Soil science
H. Asgari; M. Barani Motlagh; S.A. Movahedi Naeini; A. Babaei
Abstract
Introduction
Wheat is considered the most important grain and one of the vital food products in Iran. After nitrogen, phosphorus is the most important nutrient required by plants and holds a high priority for the growth, yield and quality of plants. However, due to the introduction of phosphorus in ...
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Introduction
Wheat is considered the most important grain and one of the vital food products in Iran. After nitrogen, phosphorus is the most important nutrient required by plants and holds a high priority for the growth, yield and quality of plants. However, due to the introduction of phosphorus in various reactions in the soil, a small amount of consumed phosphorus fertilizer is removed by the plant and the rest of it is left in a non-absorbable form in the soil. The efficiency of using phosphorus fertilizers and the availability of this nutrient is considered as a limiting factor for the production of agricultural products in calcareous soils with alkaline reaction of Iran. Since graphene and its oxidized form, with large amounts of active oxygen groups and high specific surface area, have been proposed by many studies as non-toxic and biocompatible materials in the production of compounds with improved efficiency of using nutrient, therefore to increase the efficiency of phosphorus consumption in soil, in this study, phosphorus was loaded on graphene oxide (GO-P). The present study aims to assess the influence of this compound as a source of phosphorus and its mixing with triple superphosphate fertilizer (GO-P-TSP) compared to triple superphosphate soluble fertilizer (TSP) on the amount of water retention of fertilizers in soil and phosphorus concentration in aerial parts of wheat plant.
Methods and Materials
Graphene oxide was prepared based on the modified Hamers method. Then graphene oxide was adjusted to certain pH and iron sulfate as a source of iron ions was added to the graphene oxide suspension with vigorous stirring. The mixture was stirred for one hour and then centrifuged for 30 minutes. Then the supernatant was removed and the residue of the compound was dry frozen. In the next step, pH was adjusted with sodium hydroxide (NaOH) solution. Then a certain weight of potassium dihydrogen phosphate salt (KH2PO4) was added to the above suspension. The mixture was stirred for one hour and centrifuged for 30 minutes. After centrifugation, the supernatant was removed and the remains of the phosphorus composition based on graphene oxide were dry frozen. Loading tests were performed in three replicates. pH, EC, bulk density, total concentration of phosphorus and iron and X-ray diffraction spectroscopy (EDS) analysis were measured in the sample of phosphorus composition based on graphene oxide. Then three fertilizer formulations were selected, which included (1) triple superphosphate fertilizer, (2) synthesized phosphorus fertilizer based on graphene oxide, and (3) mixing graphene oxide-phosphorus compound with triple superphosphate fertilizer in a ratio of 50:50% phosphorus.
To investigate the water retention behavior of fertilizers in the soil, dried samples of the three studied fertilizer formulations was added into a sandy soil completely and weighed. At the same time, dried sandy soil without fertilizer was placed in another beaker as a control. Then each beaker was added distilled water and weighed. The beakers were weighed once every three days at room temperature until they reached constant mass. The water-retention behavior of the soil was calculated.
In order to investigate the effect of three fertilizer formulations on phosphorus availability, soil with low amount of phosphorus was selected and physical and chemical properties of the soil sample were measured at a depth of 0-30 cm. A greenhouse experiment on wheat planting was conducted using a randomized complete design with 3 replications. The treatments included three fertilizer formulations at three fertilization levels (10, 15, and 20 mg kg-1) with 3 replications. The control treatment was performed without phosphorus fertilizer. Plants were harvested 72 days after planting, washed with distilled water and dry with tissue paper. The samples were air-dried and then oven dried at 70˚C to a constant weight in a forced air-driven oven. After harvesting, the weight of fresh and dry matter and phosphorus concentration in the soil and aerial parts of the plant were measured. Statistical data were analysed using SAS software (9.4) and the mean values were compared using LSD tests (at 1 and 5% level).
Results and Discussion
The composition of phosphorus based on graphene oxide (GO-P) in powder form had 35.5% of total P2O5, 31.1% of soluble in water P2O5, 19.6 of total iron and 15.28% of total potassium. The result of EDS analysis confirmed the loading of phosphorus on graphene oxide. The pH of the phosphorus composition based on graphene oxide was 5.8, approximately 2.5 units higher than triple superphosphate fertilizer. The bulk density of the compound (GO-P) was significantly lower than triple superphosphate fertilizer. The EC of the compound (GO-P) was similar to the EC of the triple superphosphate fertilizer. Soil water retention with synthesized phosphorus fertilizer based on graphene oxide (GO-P) was higher than soil (control) and other compounds added to soil. Experimental results showed that the addition of prepared fertilizer formulas (GO-P and GO-P-TSP) increased water retention in the soil for a longer period of time, while in the soil without adding fertilizer and triple superphosphate treatment, respectively, from 10 and 11 days, the absorbed water completely evaporated. Therefore, the combination of soil with GO-P and GO-P-TSP compared to the soil without fertilizer and the combination of soil with triple super phosphate (TSP) fertilizer had better water retention behavior. The greenhouse experiment results of wheat planting showed that all treatments were significant (P<0.01). Among all the treatments and measured levels, the control treatment showed the lowest value. The highest concentration of phosphorus in aerial parts of wheat (0.31%) and in soil after harvesting (9.5 mg kg-1), fresh (10.6 g per pot) and dry weight (2.03 g per pot) of aerial wheat plants were related to the treatment of phosphorus compounds based on graphene oxide at the level of 20 mg kg-1.
Conclusion
The highest concentration of phosphorus in aerial parts of wheat was related to the treatment of phosphorus compound based on graphene oxide at the level of 20 mg kg-1. Therefore, with more research in the future to produce "nutritious plants" in sustainable, efficient and flexible agricultural systems, we can benefit from technologies based on carbon materials.
Soil science
T. Nazari; M. Barani Motlagh; S.O. Rastegar; M.H. Sedri
Abstract
IntroductionPhosphorus is an essential element for all living organisms, and it cannot be replaced by any other element. Phosphorus has however a limited resource, and it is estimated that the extracted phosphorus resources (Apatite) will last for another 50 to 100 years. One of the most widely used ...
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IntroductionPhosphorus is an essential element for all living organisms, and it cannot be replaced by any other element. Phosphorus has however a limited resource, and it is estimated that the extracted phosphorus resources (Apatite) will last for another 50 to 100 years. One of the most widely used technologies for recycling phosphorus is the precipitation of phosphorus from sewage sludge and leachate. Phosphorus Recovery as struvite (NH4MgPO4.6H2O) from sewage sludge has attracted special attention due to its potential for use as an ecological and slow release fertilizer. Struvite is a white, grain-like solid, odor-free and sludge–free ingredient, composed of magnesium, ammonium and phosphate at equal molar concentrations. Therefore, this study is designed to examine the effect of struvite replacement with triple superphosphate fertilizer on some physiological parameters and phosphorus availability in wheat plants in calcareous soils deficient in phosphorus. Methods and MaterialsSoil with phosphorus deficiency was collected from 0-30 cm depth under arable lands of Hajjiabad-e Seyyedeh located in Ghorveh township, Kurdistan Province, Iran. The soil was air-dried and ground to pass through a 2-mm sieve, followed by laboratory analysis to determine its physico-chemical properties. The struvite used in the research was obtained by optimizing the three main factors of sulfuric acid concentration, solid-to-liquid ratio, and time for the leaching process, and the three key factors of Mg:P ratio, N:P ratio and pH for the precipitation process by Response Surface Methodology. To achieve the aim of this study a factorial experiment was carried based on completely randomized design with 4 replications. The factors included the application of different proportions of struvite replaced with triple superphosphate (S0:P100, S25:P75, S50:P50, S75:P25 and S100:P0) and 4 levels of phosphorus (0, 50, 100 and 150 kg TSP ha-1) and a total of 54 pots. The application rate for struvite was calculated based on total phosphorus (P2O5). Then 10 wheat seeds were planted in each pot at 2-cm depth which after plant emerging and greening, declined to 4 plants in each pot. The pots were randomly moved twice a week during the growth period to eliminate environmental effects. Irrigation and weeding operations were applied by hand. Plants were harvested 60 days after planting (beginning of flowering), washed with distilled water and dried with tissue paper. The samples were air-dried and then oven dried at 70˚C to a constant weight in a forced air-driven oven. Phosphorus concentrations in plant extracts were measured by the molybdenum vanadate or yellow method and chlorophyll content (a, b and ab) and carotenoids using the Arnon method. The statistical results of the data were analyzed using SAS software and LSD test (at 5% level) was used for comparing the mean values. Results and DiscussionBased on the obtained results, all the investigated treatments and their interactions were significant at p<0.01. However, the interaction effect of fresh weight shoots and height was significant at p<0.05. The comparison of the average data showed that the highest amount of fresh weight shoots (7.79 g pot-1), dry weight shoots (1.130 g pot-1) and height (29.66 cm) was obtained from the application of S75:P25 150 kgTSP ha-1. By use of struvite instead of triple superphosphate fertilizer, the phosphorus concentration and uptake of wheat increased at all three fertilizer levels, so that the highest phosphorus concentration (0.174%) was obtained from S75:P25 150 kg TSP ha-1. However, there was no statistically significant difference for S100:P0 (0.169%) treatment. The highest amount of phosphorus uptake in wheat with an average of 0.197 g pot-1 was obtained from the S75:P25 treatment (150 kg TSP ha-1), compared to the treatment of 100% struvite (S100:P0) and 100% triple superphosphate fertilizer (S0:P100) with the averages of 0.158 and 0.109 g pot-1, respectively, showing 19.79 and 44.67 percent increase. Also, the results showed that the treatment of 150 kg TSP ha-1 100% struvite (S100:P0) compared to 100% triple superphosphate fertilizer (S0:P100) increased the amounts of chlorophyll a, b, ab and carotenoids by 7.78, 3.82, 6.44 and 6.84 percent, respectively. ConclusionDespite struvite's low solubility, it is a highly soluble phosphorus fertilizer for plants . However, the reasons for this apparent contradiction and also the specific mechanisms of struvite dissolution are still unclear. Hence, further accurate measurements at different pH and EC conditions with different physical and chemical properties of soil studying phosphorus fractionation in soil will help to better understand the use of struvite. Therefore, it is recommended to optimize the timing and application rate of struvite in relation to the demand for different agricultural and garden crops.
Agricultural Meteorology
S. Shiukhy Soqanloo; M. Mousavi Baygi; B. Torabi; M. Raeini Sarjaz
Abstract
IntroductionWheat (Triticum aestivum L.) has become very important as a valuable strategic product with high energy level. The importance of investigating environmental stresses and their role in predicting and evaluating the growth and crops yield is essential. A wide range of plant response to stress ...
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IntroductionWheat (Triticum aestivum L.) has become very important as a valuable strategic product with high energy level. The importance of investigating environmental stresses and their role in predicting and evaluating the growth and crops yield is essential. A wide range of plant response to stress is extended to morphological, physiological and biochemical responses. Considering the rapid advancement in computer model development, plant growth models have emerged as a valuable tool to predict changes in production yield. These growth simulation models effectively incorporate the intricate influences of various factors, such as climate, soil characteristics, and management practices on crop yield. By doing so, they offer a cost-effective and time-efficient alternative to traditional field research methods. Material and MethodsThis research was conducted in the research farm of Varamin province, which has a silty loam soil texture. The latitude and longitude of the region are 35º 32ʹ N and 51º 64ʹ E, respectively. Its height above sea level is 21 meters. According to Demarten classification, Varamin has a temperate humid climate. The long-term mean temperature of Varamin is 11.18 ° C and the total long-term rainfall is 780 mm. In this study, in order to simulate irrigated wheat cv. Mehregan growth under drought stress, an experimental based on completely randomized blocks (CRBD) including: non-stress as control (NS), water stress at booting stage (WSB), water stress at flowering stage (WSF), water stress at milking stage (WSM) and water stress at doughing stage (WSD) with three replications during growth season 2019-2020 was carried out in Varamin, Iran. Crop growth simulation was done using SSM-wheat model. This model simulates growth and yield on a daily basis as a function of weather conditions, soil characteristics and crop management (cultivar, planting date, plant density, irrigation regime). Results and DiscussionBased on the results, the simulation of the phenological stages of irrigated wheat cv. Mehregan under water stress condition using SSM-wheat model showed that there was no difference between observed and simulated values. Summary, the values of day to termination of seed growth (TSG) were observed under non- stress, stress in the booting stage, flowering, milking and doughing of the grains, 222, 219, 219, 221, 221 days, respectively andsimulation values with 224, 221, 220, 221, respectively. However, with their simulation values, there were slight differences with 224, 221, 220, 221, respectively. Acceptable values of RMSE (11.7 g.m-2) and CV (3.5) indexes showed the high ability of the SSM model in simulating the grain yield of irrigated wheat cv. Mehregan under water stress conditions. Grain yield values were observed in non-stress conditions of 5783, water stress in booting, flowering, milking and doughing of the grain stages in 5423, 5160, 5006 and 5100 kg. h-1, respectively. While the simulated values were 5630, 5220, 4920, 4680 and 4880 kg. h-1, respectively. Based on the findings, observed and simulated values of leaf area index (LAI) were observed under water stress condition in the booting, flowering, milking and doughing of the grain stages (4.3 and 4.47), (4.33) and 4.46), (4.4 and 4.57) and (4.4 and 4.58) cm-2, respectively. Evaluation of the 1000-grain weight of irrigated wheat cv. Mehregan under the water stress showed that the SSM model was highly accurate. RMSE (4.6 g.m-2) and CV (1.8) values indicate the ability of the SSM model to simulate the 1000-grain weight of irrigated wheat cv. Mehregan. Also, the simulated values of the harvest index were 34.7 % in non-stress conditions, which decreased by 6 % compared to the observed value. Harvest index values were observed under water stress conditions in the in the booting, flowering, milking and doughing of the grain stages in 30.2, 29.3, 29.9 and 29.5 %, respectively. Compared to its observed values, it was reduced by 3, 3.5, 5, and 5.5 %, respectively. ConclusionBased on the findings, the slight difference between the observed and simulated values demonstrates the SSM model's capability to accurately capture water stress impacts on the phenological stages, grain yield, and yield components of irrigated wheat cv. Mehregan during critical growth stages, including booting, flowering, milking, and doughing. The results indicate that the SSM model is effective in simulating wheat growth under water stress conditions, showcasing its potential as a valuable tool for modeling irrigated wheat growth. The model's ability to account for water stress and its effects on various growth parameters makes it a reliable and efficient tool for predicting crop performance in water-limited environments.
Soil science
P. Kabiri Samani; M.H. Salehi; H.R. Motaghian
Abstract
Introduction In addition to the minerals, weathering in soil which depends on soil forming factors and processes, plants rhizosphere release components which affect soil minerals and finally their weathering. If the soil is polluted by heavy metals, root exudates will be influenced resulting in ...
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Introduction In addition to the minerals, weathering in soil which depends on soil forming factors and processes, plants rhizosphere release components which affect soil minerals and finally their weathering. If the soil is polluted by heavy metals, root exudates will be influenced resulting in decreasing microbial activity. Many studies showed minerals weathering in rhizospheric medium for both natural soils and pure clay minerals but information about the effect of pollution of rhizosphere on clay minerals weathering is limited. This study was conducted to investigate the effect of cadmium pollution on the transformation of clay minerals in wheat rhizosphere in a dominant soil of Shahrekord plain (Chaharmahal soil series).Materials and methods Soil samples were collected from 0-20 cm depth of Chaharmahal soil series based on the 1:50,000 scale soil map. A factorial experiment as completely randomized design with three replications and three cadmium levels (0, 5, and 10 mg kg-1 from cadmium) was performed in two environments including bulk soil and rhizospheric soil (18 samples in total) in greenhouse conditions for 16 weeks. Necessary care was taken during the growth period and the soil moisture was kept constant at the field capacity. At harvest time, the rhizosphere soil was separated from bulk soil. Then, the soil samples were air dried and passed through a 2 mm sieve. The mineralogy was examined by X-ray diffraction (XRD) in the studied soil after plant harvest (including rhizospheric soil and bulk soil) in unpolluted samples. Then, results were compared with minerals in polluted rhizosphere media. Dissolved organic carbon (DOC) and pH in the rhizosphere and bulk soils were also determined.Results and Discussion The results showed that the effect of contamination on soil pH was not significant but the pH value in rhizosphere soil was significantly lower than the bulk soil. The average pH in the soil was 7.8 and in the rhizosphere reduced to 7.5. The interaction of medium (rhizosphere and bulk soil) and contamination on the amount of dissolved organic carbon was significant (p < 0.01). The amount of dissolved organic carbon in the rhizosphere at 170.6 mg Kg-1 was significantly higher than the bulk soil (104.6 mg kg-1), which could be due to root secretions. In the rhizosphere, increasing the contamination level to 5 mg kg-1 decreased by 19% and contamination of 10 mg kg-1 caused a 21% decrease in dissolved organic carbon. The amount of dissolved organic carbon in the rhizosphere was 39% higher than the bulk soil. The average of dissolved organic carbon in the rhizosphere and bulk soil was 170.6 and 104.6 mg kg-1, respectively. Based on mineralogical results, mica, smectite, chlorite, kaolinite and palygorskite minerals were detected in the bulk soil. Comparison of clay minerals samples in the bulk soil and rhizosphere showed that the trioctahedral chlorite transformed to hydroxy-interlayer vermiculite (HIV) in the rhizosphere soil. The presence of HIV was identified by an increase in the intensity ratio of the 10 and 14 angstrom peaks after K-saturation. In rhizospheric soils, the intensity of the 14 angstrom peak decreases in K-550ºC treatment. Furthermore, in the rhizospheric soils, a clear increase in the intensity of the 10 angstrom peak was observed from K-air dried to K-550ºC treatments which can be related to the presence of HIV which can be attributed to the changing conditions of the rhizosphere, including reducing pH and increasing the dissolved organic carbon and the activity of microorganisms. Comparison of diffractograms for clay fraction of rhizospheric soil with different contamination levels after cultivation showed that the type of minerals in contaminated levels was similar to non-contaminated conditions, but the amount of trioctahedral chlorite was the highest in higher contaminated soil. The peak intensity of 14 angstrom in potassium saturated sample heated at 550°C was lower in non-contaminated soil. Also, at the level of 10 mg kg-1 cadmium contamination, the chlorite peak had the highest intensity which indicates less chlorite was transformed to HIV in the contaminated soils.ConclusionsThe results showed that DOC in the rhizosphere soil was significantly higher than the bulk soil, whereas pH significantly decreased in the rhizosphere soil compared to the bulk soil. In both the rhizosphere and the bulk soils, increasing the contamination caused a decreasing trend in dissolved organic carbon. Mineralogical results of the rhizospheric and the bulk soils showed that trioctahedral chlorite was transformed to hydroxy-interlayer vermiculite (HIV). In addition, rhizosphere contamination reduced the chlorite transformation. The results suggest that soil contamination with a negative impact on plant activity and soil could even prevent the availability of nutrients from the clay minerals structure.
mohammadreza dalalian; fatemeh zabihi; anvarossadat paknejad; mina khoshkhan
Abstract
Introduction: Destruction of soil structure and reduction of soil organic matter are major problems of cultivated soils which result from improper tillage operations, excessive consumption of chemical fertilizers and low consumption of organic and green fertilizers. One method for maintaining sustainable ...
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Introduction: Destruction of soil structure and reduction of soil organic matter are major problems of cultivated soils which result from improper tillage operations, excessive consumption of chemical fertilizers and low consumption of organic and green fertilizers. One method for maintaining sustainable agriculture is to add organic and inorganic amenders. By producing resistant aggregates, organic matters improve soil structure and enhance soil permeability, FC moisture and water availability capacity. Furthermore, through enhancing organisms’ activities, especially earthworms, organic matters improve soil hydraulic conductivity and reduce bulk density. Organic matters may be added to soil through different way, however, the effect of each one on the soil’s physical properties is different. Chicken feather (CF) is readily available through henhouses and slaughterhouses, however, significant amounts of CF are destroyed by burning and burying them. Potassium Humate (PH) is a potassium salt from humic acid. Humic acid is extracted from various natural sources such as humus, peat, lignite and coal. Vermicompost (VC) is a compost which is produced by a non-thermal process. The impact of CF on different soil properties has not been studied yet. Accordingly, we investigated the impact of adding differing weight percentages of three types of amenders (PH, CF and VC) on the physical properties of soil under wheat cultivation at different moisture levels.
Materials and Methods: The experiment was conducted in factorial form based on randomized complete block design with 27 treatments in three replications. The first factor included the above-mentioned amenders; the second factor included three weight levels of these amenders (0%, 2.5% and 5%); the third factor included three moisture levels (0.5FC, 0.7FC and 0.9FC). The amenders were uniformly mixed with the soil up to the depth of 10 cm; then, wheat seeds were planted and moisture treatments were carried out during the growth period (from late April 2016 to September 2016). The soil moisture of the plots was controlled during the experiment period using the gravimetric method. For investigating the changes in the soil’s physical properties, samples (disturbed and undisturbed) were taken from the plots before and after the experiment. The following physical parameters were measured: bulk density (BD), soil moisture in field capacity (FC), permanent wilting point (PWP), wet aggregate stability (WAS), saturated hydraulic conductivity (KS), penetration resistance (PR), retention curve slope at inflection point (Si), mean weight diameter of aggregates (MWD) and mass-size fractal dimension of aggregates (Dm). Statistical analysis was done by SPSS software and means were compared via Duncan test. Tables and graphs were generated by Excel software.
Results and Discussion: Variance analysis and means comparison indicated that using amenders reduced bulk density for 89%. Reduced bulk density was caused by high keratin (91%) in CF, high porosity and the production of coarse pores in soil. On the other hand, VC with many pores led to increased aggregation and reduced bulk density.
Results revealed that consuming CF increased soil moisture to field capacity (FC) (87%). CF had more significant impacts on increasing FC at high moisture levels. Thanks to its keratin structure, feather operates like a sponge which enhances soil porosity; hence, it absorbs more moisture and improves FC. Furthermore, results indicated that increasing the amounts of amenders led to increased soil moisture in PWP (91%). By increasing the amount of amenders in soil, aggregation and soil porosity increased which led to enhanced PWP.
Large amounts of CF, PH and soil moisture (0.9FC) resulted in 3.7 times enhancement of Ks. CF led to the production of large soil pores and reduced soil density which resulted in improved soil structure and increased Ks. Thanks to its adhesion properties, PH increased Ks.
Increasing the amount of amenders and the level of soil moisture in all three types of organic matters (especially CF) caused the 2.5 times enhancement of WAS.
The results revealed that increasing soil moisture and amenders led to reduced Si (101%). Given all three types of amenders, PH had the highest impact on the reduction of Si. Moreover, soil penetration resistance (PR) was reduced as a function of increasing the soil moisture level.
Contrary to the expectation, MWD was reduced as a result of increasing amenders. Furthermore, it was found that, given little soil moisture, increasing the amount of amenders resulted in increased Dm; however, given high soil moisture, increasing the amount of amenders led to decreased Dm. Thus, it should be noted that adding amenders improved the stability of aggregates over long time periods and at high soil moisture levels.
Conclusion: One major strategy for improving soil physical and chemical properties is using modifiers, especially organic matters. In this study, we investigated the impact of chicken feather on physical properties of soil and compared its effect with those of potassium humate and vermicompost under different levels of soil moisture and wheat cultivation.
The results indicated that consuming amenders resulted in reduced Bd but increased FC, PWP, Ks and WAS. In other words, it improved physical properties of soil. Moreover, Si decreased as a result of increasing soil moisture and organic matters. Among the three types of amenders, potassium humate had the highest impact on reducing Si. PR was reduced as a function of increasing soil moisture. However, increasing organic matter led to decreased MWD. Furthermore, it was unexpectedly found that, given low soil moisture, Dm increased as a result of increasing the organic matters weight. Nevertheless, in high levels of soil moisture, Dm decreased as a function of increasing organic matter. Thanks to positive impacts of organic matters (especially CF which is cheaper and more accessible than other amenders) on soil’s physical properties, they are highly recommended for soil improvement. Regarding future studies, investigation of the effect of these amenders on soil chemical properties under different soil textures is suggested.
Nosratollah Najafi; Rashed Ahmadinezhad; Naser Aliasgharzad; Shahin Oustan
Abstract
Introduction: Chemical fertilizers can supply all the nutrients required by plants, but their high consumptions cause environmental pollution and increased agricultural production costs. Organic fertilizers can improve the biological, physical, and chemical properties of soil and improve soil fertility ...
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Introduction: Chemical fertilizers can supply all the nutrients required by plants, but their high consumptions cause environmental pollution and increased agricultural production costs. Organic fertilizers can improve the biological, physical, and chemical properties of soil and improve soil fertility and productivity. However, these fertilizers alone cannot provide all the requirements of plants for different nutrients. In addition, these fertilizers are not sufficiently available to farmers everywhere. So, in order to increase effectiveness of organic and chemical fertilizers, to decrease environmental pollutions and to achieve sustainable agriculture, integrated application of organic and chemical fertilizers is recommended. Nitrogen (N), phosphorus (P) and potassium (K) are essential elements for plant nutrition and growth. Wheat as a strategic crop is the most important cereal and plays a very important role in human and animal nutrition and health. The deficiencies of N, P and K in the most agricultural soils often reduce the growth and yield of wheat. Therefore, the appropriate concentrations of these nutrients in wheat seed, leaf and stem are important not only for the optimum growth of the wheat plant and its quality improvement but also for the health of humans and animals.
Materials and Methods: This research work was carried out to study the effects of combining farmyard manure (FYM), municipal solid waste compost (MSWC) and municipal sewage sludge compost (MSSC) with different levels of urea on seed, leaf and stem yields of wheat (Triticum aestivum L.) cultivar Alvand and concentrations of N, P and K in seed, leaf and stem in a randomized complete blocks design with 15 treatments and three replications under field conditions at Khalatposhan Agricultural Research Station, University of Tabriz, Tabriz, Iran. The treatments included were: 1) control (without fertilizers), 2) 150 kg urea/ha, 3) 300 kg urea/ha, 4) 30 ton MSWC/ha, 5) 30 ton MSWC/ha + 150 kg urea/ha, 6) 60 ton MSWC/ha, 7) 60 ton MSWC/ha + 150 kg urea/ha, 8) 30 ton MSSC/ha, 9) 30 ton MSSC/ha + 150 kg urea/ha, 10) 60 ton MSSC/ha, 11) 60 ton MSSC/ha + 150 kg urea/ha, 12) 30 ton FYM/ha, 13) 30 ton FYM/ha + 150 kg urea/ha, 14) 60 ton FYM/ha, 15) 60 ton FYM/ha + 150 kg urea/ha. The size of each plot was 2.0m × 1.9m. At the end of growth period, the plants were harvested and different sections of wheat plant (seed, leaf and stem) were separated and the yield of each section was determined. The concentration of N in seed, leaf and stem were then measured by Kjeldahl method. After dry ashing of the seed, leaf and stem samples, the concentrations of P and K in their extracts were measured by spectrophotometer and flame photometer instruments, respectively.
Results and Discussion: The results showed that application of 300 kg urea/ha increased the wheat grain yield and concentrations of N, P and K in seed, leaf and stem but it decreased the stem yield. Application of 150 kg urea/ha had no significant effect on the leaf yield but its integration with 60 ton MSWC/ha significantly increased the leaf yield of wheat. The combining of 150 kg urea with 30 and 60 ton FYM, MSWC and MSSC per hectare increased yields of wheat stem and seed and their N and P concentrations as compared with the control and application of solely organic fertilizers. The use of FYM, MSWC and MSSC significantly increased the wheat grain yield and concentrations of N, P and K in seed, leaf and stem relative to the control but their effects on yields of leaf and stem depended on the type and rate of organic fertilizer. The highest yields of grain, stem and leaf and the highest concentrations of N, P and K in wheat grain, stem and leaf were observed under combined application of 150 kg urea and 60 ton FYM, MSWC and MSSC per hectare. The minimum yields of seed, leaf and stem and the minimum concentrations of N, P and K in different organs of wheat plant were observed in the control treatment. The average wheat yield component was in the order of seed > stem > leaf. The mean concentrations of N, P and K in different sections of wheat were in the order of seed > leaf > stem, seed > leaf > stem and stem > leaf > seed, respectively. The grain yield of wheat had positive and significant correlations (p<0.01) with concentrations of N, P and K in different organs of wheat, which indicates the role of N, P and K nutrition of wheat plant in increasing its seed yield.
Conclusions: The wheat seed had higher concentrations of N and P and lower concentration of K compared to leaf and stem. In general, in order to decrease nitrogen fertilizers use, enhance N, P and K nutrition of wheat plant, improve wheat seed quality, decline environmental pollution and increase wheat yield, application of 150 kg urea and 60 ton manure per hectare is recommended. However, if there is not enough manure, 150 kg urea and 60 ton municipal solid waste compost or municipal sewage sludge compost per hectare can be applied at similar conditions.
Mohammad Reza Emdad; arash tafteh; saeed ghalebi
Abstract
Introduction: Simulation models have been used for decades to analyse crop responses to environmental stresses. AquaCrop is a crop water productivity model developed by the Land and Water Division of FAO. It simulates yield response to water of herbaceous crops, and is particularly suited to address ...
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Introduction: Simulation models have been used for decades to analyse crop responses to environmental stresses. AquaCrop is a crop water productivity model developed by the Land and Water Division of FAO. It simulates yield response to water of herbaceous crops, and is particularly suited to address conditions where water is a key limiting factor in crop production. It is designed to balance simplicity, accuracy and robustness, and is particularly suited to address conditions where water is a key limiting factor in crop production. AquaCrop is a companion tool for a wide range of users and applications including yield prediction. Aquacrop has high accuracy and performance for yield prediction than other models regarding to irrigation and fertilizer management base foundation. Using Aquacrop model for crop yield simulation in different soil and water managements has high accuracy and its use requires calibration and validation. The use of models saves time and cost and, if calibrated and validated, acceptable results are expected.
Material and Methods: This research was carried out in order to calibrate and validate the Aquacrop model for simulating wheat grain yield in the three selected pilots in Hamidiyeh province of Khuzestan province in two years of cultivation.In this regard, three different plots with a total area of about 10 hectares were selected in Hamidyeh region. Sampling, measuring and determining the parameters of soil, water, plant, irrigation management (information required for the Aquacrop model) and the existing conditions of the area were carried out.The climatic data required in Aquacrop model was collected from synoptic meteorological weather station of Ahvaz. Irrigation water quality with mean water salinity of 1.9 dS/m has a good quality for irrigation. In the first year, 5 irrigation events (with a total volume of 9500 cubic meters per hectare) are available to the wheat plant at different stages. In this regard, based on meteorological data and field and vegetation data that was taken from the field level in the first year, the Aquacrop model calibration and performance variations were carried out at different times of irrigation using a simulation model. In order to validate the results simulated by the model, the best scenario provided by the model in the second year was implemented at selected farm level and its results were compared with the simulation results by the model.
Results and Discussion: Aquacrop model calibrated for the first year and then compared for different scenarios of irrigation timing (3-6 irrigation event).The amount of grain yield and total in 4 irrigation intervals are not different with the corresponding values in 5 irrigation intervals. Irrigation rotations were considered in accordance with routine irrigation rotations of the region during planting, tillering, stemming, flowering and seed filling (5 turns) for 4 steps of irrigation step and for 3 irrigation stages, the tiller and stem elongation was deleted. The model showed that, using four irrigation timing is the most appropriate irrigation scenario. Using the results of the model with considering 4 irrigation times, wheat was planted in the second year for model validation. In the second year, the average of measured and simulated wheat grain yield was 3.8 and 4.4 t/h (with 14% error).Average values of total yield and simulated wheat seeds in 4 and 5 irrigation intervals were not different, while the amount of water consumed in 4 irrigation intervals decreased by 20% compared to 5 irrigation intervals. On the other hand, water use efficiency increased by up to 21% in 4 irrigation intervals compared to 5 irrigation intervals. Also, according to the simulation, it was observed that increasing the irrigation interval at the arrival stage, while not significantly increasing the grain yield and the total, did not increase the water use efficiency in order to increase the water consumption (one irrigation interval) Reduced. Considering 3 irrigation timing, the grain yield decreased by 15%. Due to the reduced yield in three irrigation intervals than the more irrigation intervals, this scenario is not recommended for performance reasons. So, according to the simulation, at least 4 irrigation intervals (during planting, stemming, flowering and seed filling) are recommended to maintain proper production level in existing conditions. Comparison of statistical indices between measured and simulation values of wheat grain yield in both years showed that the coefficient of correlation, normalized root mean square error (RMSE) and agreement index were 0.9, 0.14, and 0.89 respectively, which indicates the proper performance of the model for simulating yield of wheat for two consecutive years. The average grain yield of simulated wheat has been estimated at 3.8 ton / ha, which estimates 14% of grain yield less than actual experimental conditions compared to its measured value, indicating the accuracy and efficiency of this model in simulating wheat yield in the present situation. With considering 4 irrigation events, the water use efficiency of wheat grain yield increased by 0.7 kg/m3, which confirms the ability and accuracy of the Aquacrop model for simulating grain yield of wheat and also improving water use efficiency.
Conclusions: The results of this study showed that the simulation of wheat yield in the first year (2.6 t/ha) has a close proximity to the measured values of yield (3 t/ha). Also, validation of the model with changing conditions in the second year showed that the simulated yield of wheat (4.4 t/ha) also had a good agreement with its measured value (3.8 t/ha), which indicates the high accuracy of this model in simulating wheat grain yields every two years. Therefore, this model has the efficiency and accuracy in simulating wheat yield in research conditions.
Vida Hemmati; Hadi Asadi Rahmani; Shokofeh Rezaee
Abstract
Introduction: Wheat is one of the most important food crops. In modern agriculture, due to the increase in human population and the detrimental effects of pesticides such as environmental pollution, concerns about human and animal health, adapting suitable alternatives which have none of these dangerous ...
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Introduction: Wheat is one of the most important food crops. In modern agriculture, due to the increase in human population and the detrimental effects of pesticides such as environmental pollution, concerns about human and animal health, adapting suitable alternatives which have none of these dangerous effects would be necessary. This is possible by increasing the production of bio-fertilizers. Plant growth-promoting rhizobacteria (PGPR) are the beneficial rhizosphere bacteria that can enhance plant growth directly or indirectly through a wide variety of mechanisms. PGPR can stimulate plant growth directly by supplying nutrients such as phosphorous and nitrogen or by the production of phytohormones such as auxins, cytokinins (CK), gibberellins (GAs) or ACC deaminase synthesis. They can also promote plant development indirectly by the suppression of pathogens by different mechanisms such as biosynthesis of antimicrobial molecules or antibiosis induced systemic resistance (ISR), rhizosphere competition, cell wall degrading enzymes like chitinase and HCN production. In this study, amplified ribosomal DNA restriction analysis was performed for screening the bacterial isolates. Then phosphate solubilization, siderophore and auxin release activities and effect of bacterial isolates on wheat seed germination traits were studied.
Materials and Methods: In order to isolate wheat rhizosphere bacteria, soil samples were taken from the wheat rhizosphere of Tehran, Qazvin, Zanjan, West and East Azerbaijan, Kurdistan and Hamadan provinces. Genomic DNA of each isolate was extracted by using a modified cetyl trimethylammonium bromide (CTAB) method. Amplified ribosomal DNA restriction analysis with HpaII and RsaI restriction enzymes was done for genetic screening. Growth stimulating factors were evaluated by auxin production, siderophore production, and inorganic phosphate solubilizing activity. Siderophore production was determined by measuring the diameters of the colony (mm) and of any orange halo (mm) formed from the blue medium surrounding bacterial growth on CAS Blue Agar medium. To examine Pi solubilization capability, 2µ bacteria suspension was placed on the plates containing Sperber’s medium. Cultures were incubated at 25 ± 2 °, when the diameters of the colony and of the halo zone surrounding it were measured and the mean ± SE of the ratios of halo (mm)/colony (mm) calculated. In order to evaluate the production of auxin, isolates were grown in 100ml flasks containing 25ml TSB medium for 48h on a rotary shaker. 1 ml supernatant was mixed with 2ml of Salkowsky reagent after centrifugation at 10000g for 15min. The absorbance of the complex was read at 535nm in a Spectrophotometer. To investigate the effect of bacterial isolates on germination traits, radicle and plumule fresh and dry weight, radicle and plumule length, germination percentage, germination rate, and germination average rate were measured. The data were analyzed with using SAS 9.1. Mean comparisons were performed by LSD and main effective interaction was found significant at P < 0.05.
Results and Discussion: 20 isolates of wheat rhizosphere bacteria were subjected to amplified ribosomal DNA restriction analysis. The 16S rDNA region was amplified by polymerase chain reaction and PCR products were digested by HpaII and RsaI restriction enzymes. From each pattern, one sample was sent to sequencing. Different species including; Chryseobacterium ginsenosidimutans, C. lathyri, C. piperi, C. taiwanense, Novosphingobium aromaticivorans, Pedobacter duraquae, and Sphingomonas koreensis were identified from the wheat rhizosphere. Bacteria were tested for their plant growth promoting qualities. All of the strains produced auxin from 1.90 to 25.93. Mean comparison of the data showed that the highest level of auxin was produced with F1 and the lowest amount was observed by F18. Phosphate solubilization measured as a halo zone on Sperber’s medium was observed with F6 and F56 isolates. The ratio of the diameter of the halo zone to the colony diameter was 2.86 with F6. The highest level of siderophore production by wheat rhizosphere bacteria, observed as halo formation around colonies on CAS Blue Agar medium, was obtained with F46, followed by F45 and F3. The ratio of the diameter of the orange halo surrounding bacterial growth to the colony diameter was 2.86 with F46. The result showed that the effect of wheat rhizosphere bacteria on germination traits such as radicle fresh and dry weight, plumule fresh weight, radicle and plumule length, germination percentage, germination rate, and germination average rate was significant at the one percent level and the effect of wheat rhizosphere bacteria on plumule fresh weight was significant at the five percent level.
Conclusion: Plant growth promoting bacteria enhance the growth and development of plants with different ways. These bacteria affect the growth and development of crops by phosphate solubilization, production of hydrogen cyanide, siderophore, and hormones such as auxin, gibberellic acid and cytokinins. According to the result, due to growth promoting characteristics such as siderophore and auxin production, phosphate solubilization, and the improvement of the seed germination traits, it can be possible to prepare bacterial inoculant for the field experiment in order to increase the availability of nutrients and improve the growth of plants.
shahrzad kabirinejad; mahmoud kalbasi; amir khoshgoftar manesh; M. Hoodaji; Majid Afyuni
Abstract
Introduction: Preceding crops as a source of organic matter are an important source of micronutrient and can play an important role in the soil fertility and the micronutrients cycle of soil. In addition to the role of the organic matter in increasing the concentration of micronutrients in soil solution, ...
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Introduction: Preceding crops as a source of organic matter are an important source of micronutrient and can play an important role in the soil fertility and the micronutrients cycle of soil. In addition to the role of the organic matter in increasing the concentration of micronutrients in soil solution, attention also should be paid to the role of the kind and the quantity of the root’s exudates that are released in response to the incorporation of different plant residues in the rhizosphere. Present research was conducted with the objective of studying the effect of the kind of preceding crops: Trifolium (Trifolium pretense L), Sofflower (Carthamus tinectirus L), Sorghum (Sorghum bicolor L), Sunflower (Heliantus annus L) and control (fallow) on the chemical forms of copper in the wheat rhizosphere and the bulk soil and Cu uptake by wheat and also investigating the correlation between the fractions of Cu in soil and Cu uptake in wheat.
Materials and Methods: The present research was conducted as split plot in a Randomized Complete Block design (RCBD) with 3 replications and 5 treatments, in field conditions. In the beginning, the preceding crops were cultivated in the experimental plots and after ending growth, preceding crops were harvested. Then the wheat was cultivated in the experimental plots. Finally, after harvesting the wheat, soil samples were collected from the two parts of the root zone (the wheat rhizosphere and the bulk soil). The soil samples were air dried ground and passed through a 2-mm sieve and stored for chemical analysis. Soil pH (in the soil saturation extract) and organic matter (Walkley–Black wet digestion) were measured in standard methods (1). The Total Organic Carbon (TOC) was measured by Analyzer (Primacs SLC TOC Analyzer (CS22), Netherlands). The available Cu in soil was extracted by DTPA and determined using atomic absorption spectroscopy (2). The fractionation of soil Cu was carried out using the MSEP method (3).
Results and Discussion: The results showed that the preceding crops significantly decreased soil pH, also significantly increased the DOC and DTPA-extractable Cu.These changes were higher in the Trifolium preceding treatment in the rhizosphere soil. Also, the preceding crops significantly decreased Carbonate -Cuand Residual-Cu fractions in the wheat rhizosphere compared with the bulk soil. The preceding crops (except Trifolium) significantly increased Oxide-Cu fraction. The soil Oxide- Cu fraction was higher in the rhizosphere in comparison with the bulk soil. The preceding crops increased the Organic-Cu in both the wheat rhizosphere and the bulk soil and it was higher in Trifolium treatment. The preceding crops increased Cu uptake by wheat and Organic-Cu positively correlated with Cu uptake by wheat.
Conclusion: The Organic-Cu fraction increased in the rhizosphere compared with the bulk soil, whereas Oxide- Cu, Carbonate–Cu and Residual-Cu fractions decreased. According to the results, the observed increase in the copper concentration of organic fraction in the rhizosphere was due to the decrease in the copper concentration of carbonate, oxide and residual fractions. In fact, the main process is the transmission of copper from carbonate, oxide and residual fractions to another fraction. Also, the results showed that the root exudates of the preceding crops and wheat affected the different forms of copper in the soil solid phase. Furthermore, the results of copper forms correlation analysis with Cu uptake by wheat showed that the Organic-Cu fraction had more important role in supplying copper was needed for wheat. Therefore, the preceding crops increased the copper concentration of organic fraction in the rhizosphere compared with the bulk soil, and these changes are associated with increasing the amount of copper uptake in wheat.
M. Delghandi; S. Broomandnasab; B. Andarzian; A.R. Massah-Bovani
Abstract
Introduction In recent years human activities induced increases in atmospheric carbon dioxide (CO2). Increases in [CO2] caused global warming and Climate change. Climate change is anticipated to cause negative and adverse impacts on agricultural systems throughout the world. Higher temperatures are expected ...
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Introduction In recent years human activities induced increases in atmospheric carbon dioxide (CO2). Increases in [CO2] caused global warming and Climate change. Climate change is anticipated to cause negative and adverse impacts on agricultural systems throughout the world. Higher temperatures are expected to lead to a host of problems. On the other hand, increasing of [CO2] anticipated causing positive impacts on crop yield. Considering the socio-economic importance of agriculture for food security, it is essential to undertake assessments of how future climate change could affect crop yields, so as to provide necessary information to implement appropriate adaptation strategies. In this perspective, the aim of this study was to assess potential climate change impacts and on production for one of the most important varieties of wheat (chamran) in Khouzestan plain and provide directions for possible adaptation strategies.
Materials and Methods: For this study, The Ahvaz region located in the Khuzestan province of Iran was selected.
Ahvaz has a desert climate with long, very hot summers and mild, short winters. At first, thirteen GCM models and two greenhouse gases emission (GHG) scenarios (A2 and B1) was selected for determination of climate change scenarios. ∆P and ∆T parameters at monthly scale were calculated for each GCM model under each GHG emissions scenario by following equation:
Where ∆P, ∆T are long term (thirty years) precipitation and temperature differences between baseline and future period, respectively. average future GCM temperature (2015-2044) for each month, , average baseline period GCM temperature (1971-2000) for each month, , average future GCM precipitation for each month, , average baseline period GCM temperature (1971-2000) for each month and i is index of month. Using calculated ∆Ps for each month via AOGCM models and Beta distribution, Cumulative probability distribution function (CDF) determined for generated ∆Ps. ∆P was derived for risk level 0.10 from CDF. Using the measured precipitation for the 30 years baseline period (1971-2000) and LARS-WG model, daily precipitation time series under risk level 0.10 were generated for future periods (2015-2045 and 2070-2100). Mentioned process in above was performed for temperature. Afterwards, wheat growth was simulated during future and baseline periods using DSSAT, CERES-Wheat model. DSSAT, CERES4.5 is a model based on the crop growth module in which crop growth and development are controlled by phenological development processes. The DSSAT model contains the soil water, soil dynamic, soil temperature, soil nitrogen and carbon, individual plant growth module and crop management module (including planting, harvesting, irrigation, fertilizer and residue modules). This model is not only used to simulate the crop yield, but also to explore the effects of climate change on agricultural productivity and irrigated water. For model validation, field data from different years of observations were used in this study. Experimental data for the simulation were collected at the experimental farm of the Khuzestan Agriculture and Natural Resources Research Center (KANRC), located at Ahwaz in south western Iran.
Results and Discussion: Results showed that wheat growth season was shortened under climate change, especially during 2070-2100 periods. Daily evapotranspiration increased and cumulative evapotranspiration decreased due to increasing daily temperatures and shortening of growth season, respectively. Comparing the wheat yield under climate change with base period based on the considered risk value (0.10) showed that wheat yield in 2015-2045 and 2070-2100 was decreased about 4 and 15 percent, respectively. Four adaptation strategies were assessed (shifting in the planting date, changing the amount of nitrogenous fertilizer, irrigation regime and breeding strategies) in response to climate change. Results indicated that Nov, 21 and Dec, 11 are the best planting dates for 2015-2045 and 2070-2100, respectively. The late season varieties with heat-tolerant characteristic had higher yield in comparison with short and normal season varieties. It indicated that breeding strategy was an appropriate adaptation under climate change. It was also found that the amount of nitrogen application will be reduced by 20 percent in future periods. The increase and decease of one irrigation application (40mm) to irrigation regime of base period resulted in maximum yield for 2015-2045 and 2070-2100, respectively. But, reduction of two irrigation application (80mm) resulted in maximum water productivity (WPI).
Conclusions In the present study, four adaptation strategies of wheat (shifting in the planting date, changing the amount of nitrogenous fertilizer, irrigation regime and breeding strategies) under climate change in Ahvaz region were investigated. Result showed that Nov, 21 and Dec, 11 were the best planting dates for 2015-2045 and 2070-2100, respectively. The late season varieties with heat-tolerant characteristic had higher yield in comparison with short and normal season varieties. It indicated that breeding strategy was an appropriate adaptation strategy under climate change. It was also found that the amount of nitrogen application will be reduced by 20 percent in future periods. The increase and decease of one irrigation application (40mm) to irrigation regime of base period resulted in maximum yield for 2015-2045 and 2070-2100, respectively.
F. rejali; A. Esmaelzad; K. Saghafi; V. hemati
Abstract
Introduction: Biofertilizers have been identified as alternative to chemical fertilizers to increase soil fertility and crop production in sustainable farming systems. One of the most useful kind of biofertilizers include plant growth promoting rhizobacteria (PGPR). Azospirillum is an associative rhizobacteria ...
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Introduction: Biofertilizers have been identified as alternative to chemical fertilizers to increase soil fertility and crop production in sustainable farming systems. One of the most useful kind of biofertilizers include plant growth promoting rhizobacteria (PGPR). Azospirillum is an associative rhizobacteria which can be very useful for plants such as wheat. It can help plant by fixing nitrogen through biological way, causing root development, plant strength improvement in primary phases, causing germination percent increment, improving plant tolerance in stress situations (drought, salinity, soil compaction and pathogens), secreting plant promoting hormones like cytokinin, Oxin and finally yield increment will be observable. Modern agriculture largely relies on the extensive application of agrochemicals, including inorganic fertilizers and pesticides. Although pesticides are important, their effects on nontarget organisms are of great concern because this poses a risk to the entire ecological system. The fungicides may also adversely affect the soil microflora, especially the types of microorganisms that can applied to seeds as bacterial inoculants. Considering useful effects of plant growth promoting rhizobacteria especially Azospirillum on Wheat, this study was done in order to survey interaction effects between fungicide and available biofertilizers in Iran market.
Materials and Methods: Effect of carboxin tiram in 2 levels (applied, non-applied) as fungicide, on efficacy of wheat plant (Chamran Cultivar) and final crop yields under association conditions with 5 Azospirillum species (A.brasilense, A.lipoferum, A.halopraeferense, A.irakense, A.sp) using powdery and liquid formulation were studied in a greenhouse test for four months in Soil and Water Research Institute.At first some properties of used soil, including soil texture, pH, EC,organic carbon and available soil K, P, Fe, Zn, Mn and Cu were measured by laboratory methods.Nutrient Broth medium were used for bacterial inoculum production with 108 bacterial cound per ml in final suspention. Using factorial experiment in a Completely Randomized Design (CRD), 2 bacterial inoculants factors (5 inoculation level and a non-inoculation level), CarboxinThiram fungicide levels (applied, non-applied) and two inoculants formulations (liquid and powdery) with four replicates per treatment and a total of 96 experimental units (pots), the most effective contribution of different species of Azospirillum bacteria with Chamran wheat varieties were evaluated in the presence of the fungicide. Studied Parameters included number of tillers, node interface, flag length, number of grains per spike, grain weight per spike, shoots wet weight, 1000 grain weight and shoot dry weight of wheat plant. Data were analyzed with SASS and Excel softwares. The comparison was done by Tukey test.
Results and Discussion: Regarding ANOVA table (table 2), liquid and powdery formulations of Azospirillum with different species had significant effect on 8 of 11 studied traits including number of tillers, plant hight, spike length, node interface, flag length, number of spikes per square meter , grain weight in spike, shoot wet weight, shoot dry weight. Fungicide had effect on 2 traits such as number of grain per spike and grain weight spike independently. Bacteria and fingicide interaction had significant effect on number of tillers, node interface, flag length, number of grain per spike, shoot dry weight (p< 0.01) and shoot wet weight (p< 0.05).
Numeric comparsion between similar treatments in presence and absence of fungicide, it can be concluded that although fungicide presence had no significant positive effectson studied traits, it did not have any negative effects eigther.Even it could increase traits quantity by affecting on bacteria. Also, regarding to Table 5, comparing fungicide effect on bacteria with studied trait in two formulations, it can be concluded that fungicide presence with bacteria was effective on quantity of some trait in powdery formulation and some in liquid formulation.These findinds may be the result of fungicide effects in controlling soil born pathogens in compatable treatments with used bacterial inoculums.
Conclusions: As final result, using A.lipoferum with both formulations and A.halopraeferense with powdery formulation, because of high compatibility with carboxin thiram fungicide can be advised in case of fungicide application. This advice can have good effects on functional traits such as number of tillers, grain weight in spike and shoot dry weight.To consider the effects of environmental conditions on the final results we propose to do this experiment in field scale in some Iranian provinces with different climatic conditions.The use of different concentrations of carboxin tiram and also different kinds of PGPR and other fungicides must be consider in future experiments.
Alireza Hosseinpur`; hamid reza motaghian
Abstract
Introduction: Application of organic fertilizers in agricultural soils with low organic matter content is one of the best ways of nutrientsaddition to these soils. Different organic fertilizers have different effects on nutrient availability in soil. Moreover study of the distribution of nutrients in ...
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Introduction: Application of organic fertilizers in agricultural soils with low organic matter content is one of the best ways of nutrientsaddition to these soils. Different organic fertilizers have different effects on nutrient availability in soil. Moreover study of the distribution of nutrients in the soil allows investigating their mobility and bioavailability. The nutrients availability and kinetics of nutrients desorption into the soil solution is often closely related to the distribution of nutrients to different fractions in the soil. It has been assumed that the factors influencing metal fractionation and availability in soil include rate of amendment application, amount of nutrients in amendment, root-induced pH changes, metal binding by root exudates, root-induced changes of microbial activities, and metal depletion because of plant uptake.
Materials and Methods: In this study, availability and fractionation of Zinc (Zn) and Copper (Cu) were compared in one calcareous soil amended with 0, 0.5, and 1% (w/w) of cow manure and vermicompost in a completely randomized design. Also, wheat was planted in treated and untreated soils in greenhouse condition.Available Zn and Cu were determined using different methods (DTPA-TEA, AB-DTPA, and Mehlich 3). For Zn and Cu fractionation, the soil samples were sequentially extracted using an operationally defined sequential fractionation procedure, based on that employed by Tessier et al. (1979) in which increasingly strong extractants were used to release Zn and Cu associated with different soil fractions. Five Zn and Cu -fractions were extracted in the following sequence: Step 1: exchangeable fraction (a 8 ml volume of 1.0 MNaOAc (pH= 8.2) for 120 min. at room temperature)., Step 2: carbonate-associated fraction (a 8 ml volume of 1.0 MNaOAc adjusted to pH 5.0 with acetic acid for 6 h at room temperature, Step 3: iron-manganese oxides-associated fraction (20 ml of 0.04 M NH2OH.HCl in 25% (v/v) HOAc for 6 h at 96 0C)., Step 4: organic matter-associated fraction (3 ml of 0.02 N HNO3 adjusted to pH 2 and 5 ml 30% H2O2 (adjusted to pH 2.0 with HNO3) and at 85 0C for 2 h in sequence, followed by 3 ml of 30% H2O2 (adjusted to pH 2.0 with HNO3) the sample was heated to 85 0C for 3 h with intermittent agitation. After cooling, 5 ml of 3.2 M NH4OAc in 20% (v/v) HNO3 was added and agitated continuously for 30 min. Finally step 5: residual fraction was determined using 4 M HNO3 (a 12.5 ml volume of 4 M HNO3, for 16 h at 80 0C). Concentrations of Zn and Cu in all extractants were determined by AAS.
Results and Discussion: The results showed that the effect of treatments on amount of extracted Zn by different methods were significant (P0.05). The minimum and maximum of extracted Zn by DTPA-TEA were in untreated soil (0.73 mg/kg) and treated soils with 1% manure (1.30 mg/kg) and treated soils with 1% manure (1.17 mg/kg), respectively. The results showed that the effect of treatments on Zn associated with Fe-Mn oxides and Zn associated with organic matter was significant (P0.05). The correlation between extracted Zn and Cu by DTPA-TEA and AB-DTPA with Fe-Mn oxides fraction were significant (P
A. Fallah Nosrat Abad; Sh. shariati
Abstract
The high cost of fertilizers in farming systems, soil pollution and degradation of soil are factors that caused to full use of available renewable nutrient sources of plant (organic and biological) with optimal application of fertilizers in order to maintain fertility, structure, biological activity, ...
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The high cost of fertilizers in farming systems, soil pollution and degradation of soil are factors that caused to full use of available renewable nutrient sources of plant (organic and biological) with optimal application of fertilizers in order to maintain fertility, structure, biological activity, exchange capacity and water-holding capacity of the water in soil. Therefore, in recent years, according to investigators biofertilizers and organic farming as an alternative to chemical fertilizers has been drawn. Through this study, we examined the effects of triple superphosphate, organic matters and phosphate solubilizing microorganisms on quantitative and qualitative yield of wheat and nutrient uptake. The experiment was carried out in the factorial based on randomized complete block design. The factors were: 1-phosphate solubilizing bacteria in three levels including control, Pseudomonas Putida and Bacillus Coagulans bacteria, 2- triple superphosphate in five levels of 0, 25%, 50%, 75% and 100% and 3-organic matter in 2 levels of 0 and 15 ton/ha in the soil with high phosphorous accessibility (13 mg/kg soil) but lower than sufficient limit for plant 15 mg/kg soil). The results showed that the highest amount of yield has been recorded in Pseudomonas Putida bacteria treatment with organic matter and 25% phosphate fertilizer. As a result, at the conditions of this experiment phosphate solubilizing bacteria and organic matter significantly had higher yield than control and their combination with phosphate fertilizer had significant effect on reducing phosphate fertilizer use.
M. Jiriaie; E. Fateh; A. Aynehband; E. Sepehr
Abstract
Introduction: Providing the nutritional requirements of agricultural crops by non-chemical resources is a new approach in the organic farming that has attracted the attention of both the researchers and the consumers in recent years. Therefore, it is highly important to find new fertilizer resources ...
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Introduction: Providing the nutritional requirements of agricultural crops by non-chemical resources is a new approach in the organic farming that has attracted the attention of both the researchers and the consumers in recent years. Therefore, it is highly important to find new fertilizer resources that are both economically able to provide the nutritional needs of the crop plants and have no adverse effects on the consumers and the environment.
Materials and Methods: With this approach, an experiment was conducted in the research station of Shahid Chamran University of Ahvaz, Iran in 2012-13. The experimental design was factorial based on randomized complete blocks design with three replications. The treatments including Mycorrhizal fungi in three levels (i.e. no use of strain; use of Glomus intraradices strain; and use of Glomus mosseae strain), bacteria Azospirillum lipoferum in two-levels (i.e. non-inoculated and inoculated) and wheat cultivars in three levels (i.e. Chamran; Dena; and Behrang). The measured parameters include the concentration of macronutrients (i.e. nitrogen, phosphorus and potassium) and some micronutrients (i.e. zinc, iron and manganese) in two part seed and the root of wheat.
Results and Discussion: Surveying the elements content in the root and the grain indicated a significant and positive effect of the use the Azospirillum and Mycorrhiza to improve the concentration of the elements in wheat cultivars. However, the simultaneous use of these microorganisms led to an increase of the effects of their application on their assessed traits.Finally the highest concentration of N (2.21 present), P (0.50 present) and Fe (33.88 mg.kg-1) were observed in the grain; the highest concentration of K (0.93 present and 0.54 present) and Mn (43.11 and 23.63 mg.kg-1) were observed in the grain and root, respectively. Moreover, the highest concentration of Zn in the root (19.70 mg.kg-1) was obtained from inoculation of C.V Dena seeds with Azospirillum and the use of G. mosseae. Also, in the general case of Mycorrhiza fungi use (between 6 to 20 present) and seed inoculation with Azospirillum lipoferum (between 8 to 25 present), the improved nutrient content in the seeds as well as greatest impact of Mycorrhiza use is in increasing the content of the grain Zn (20 present) and the lowest effect of Mycorrhiza using is in increasing the nitrogen content in seed (6 percent). Considering the elements content in the grain, the use of bacteria also showed that the greatest impact on increasing the use of bacteria Azospirillum lipoferum is in increasing the iron content in seeds (25 present) and the least impact of the use of Azospirillum lipoferum is in increasing the seed’s manganese (8 present). Moreover, the use of Mycorrhiza fungi (between 7 and 23 present) and seed inoculation with Azospirillum lipoferum (4 to 16 present) improved the contents of nutrients in wheat roots compared with the control group. Here, too, the greatest impact for Mycorrhiza application was in increasing the content of the Zn in the root (23 present) and the lowest effect of Mycorrhiza application was in increasing the potassium content in the root (7 percent). Moreover, considering the elements content in the roots in the case of being treated with Azospirillum lipoferum, the results showed that upon increasing the use of bacteria, the greatest impact of Azospirillum lipoferum in increasing elements content in the roots was an increased iron content in the root (16 present) and the minimum effect of the bactericidal application was in increasing the potassium root (4 present). Comparing the two species of Mycorrhizal fungi that have been used in the experiment, although application Glomus intraradices showed satisfactory results, the use of the species Glomus mosseae to increase the content of the element in seeds and roots has had a greater role. Moreover, the combined effects of these microorganisms have not only had an antagonistic effect of reducing the amount of content, they have also been more effective than being applied separately (between 7 and 12 present).
Conclusion: Generally associated with most of the measured elements, the treatment of seed inoculation with Azospirillum lipoferum and usage of Glomus mosseae in Dena cultivar that was a durum wheat, showed the highest concentration of the mentioned elements in the roots and seeds. Probably this has been due to the smaller grains in Dena than the other cultivars, which led to an increase in the ratio of the elements in the grain. Therefore, it seems that the use of the biofertilizers can be the perfect solution to eliminate the nutritional requirements of wheat. Moreover, it has the very important effect of the enrichment of this crucial product in the people’s dietary patterns in this country with the required elements.
Keywords: Azospirillum, Nutrition, Wheat, Root, Elements concentration, Mycorrhiza
P. Keshavarz; M. Forouhar; M. Dadivar
Abstract
Introduction: World cereal demand is growing at the present in accordance with the global expansion of human populations.Bread wheat is the most widely grown cereal grain with 65% (6.5 million hectares) of the total crop cultivated area in Iran. Deficiency of micronutrients in cereal cropping is one ...
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Introduction: World cereal demand is growing at the present in accordance with the global expansion of human populations.Bread wheat is the most widely grown cereal grain with 65% (6.5 million hectares) of the total crop cultivated area in Iran. Deficiency of micronutrients in cereal cropping is one of the major worldwide problems. Zinc (Zn) is an essential micronutrient for plants. It plays a key role as a structural constituent or regulatory co-factor of a wide range of different enzymes and proteins in many important biochemical pathways. Nearly half of the world’s cereal-growing areas are affected by soil zinc deficiency, particularly in calcareous soils of arid and semiarid regions. High pH levels and bicarbonate anion concentration in these soils are the major factors resulting in low availability of Zn. About 40% of the soils, used for wheat production in Iran are Zn-deficient, which results in a decrease in growth and wheat grain yield under field conditions. Although application of zinc fertilizers is a common practice to correct Zn deficiency, growing varieties with high Zn efficiency has been reported to be a more sustainable approach. There is significant genetic variation both within and between plant species in their ability to maintain significant growth and yield under Zn deficiency conditions. Plant response to Zn deficiency and Zn fertilization are two distinct concepts. Knowing about these variations, can be very essential and useful for making correct fertilizer recommendation.
Materials and Methods: In order to investigate Zn efficiency in various wheat genotypes, a factorial experiment as a randomized complete block design was carried out with three replications in agricultural research center of Khorasan razavi (Torough Station), during 2009-2011. Treatments consisted of two levels of Zn fertilizer (0 and 40 kg/h as ZnSO4) and six genotyps of wheat including: three cultivars and one line of bread wheat (Alvand, Falat, Toos, and C75-5 respectively), two species of wheat known as Thriticosecale and Durum. The plot size was 9*3.6 (32.4 m2). Soil fertility status showed 0.05% nitrogen, 7.2 mgkg-1 phosphorus, 180 mgkg-1 potassium and 0.52 mgkg-1 DTPA extractable zinc. At defined phonological stage (SG6 based on Fix’s Index) Zn concentration in shrub was measured. Also grain yield and Zn uptake by grain were determined at the end of ripening stage. Zinc use efficiency, agronomic efficiency and apparent recovery efficiency were calculated according to “Graham, et al.”, “Craswell and Godwin” and “Raun and Johnson” respectively. Zinc use efficiency can be defined as the ratio of grain yield or shoot dry matter yield produced under Zn deficiency to that produced under Zn fertilization.
Results and Discussion: Grain yield is the most integrative trait of a particular genotype. The results showed that Zn application increased significantly grain yield by 12.61% in comparison with control. This result is supported by Ziayeian and Malakouti (1999). Who reported that Zn application significantly increased the wheat yield (17%). In our research the highest grain yield increase due to Zn application was found in durum wheat (23.5%), and the lowest grain yield increase, were found in Toos cultivar (1.3% yield increase). Cakmak and et al (1997) also obtained more yield with the application of zinc in durum wheat. Application of Zn increased Zn concentration and uptake in grain, 8.6% and 21.5% respectively. Also, application of Zn significantly increased Zn concentration in shoot (36.5%) over the control. Similarly, Moshiri et al (2010) reported increase of Zn concentration in shoot with application of Zn fertilizer. Zn use efficiency in bread wheat genotype, Durum and Thriticosecale wheat was ranked as: Durum < C75-5 < Alvand < Falat < Triticale ~ Toos. The findings of Khoshgoftarmanesh et al (2004) showed that, Durum wheat is Zn inefficient genotype. According to our research results, Toos and Falat cultivars and Thriticosecale have higher efficiency than Alvand and C75-5 cultivars and Durum wheat. The results also suggest that to obtain higher yield in Durum wheat, soil and foliar application of Zn is more necessary in comparison with other genotypes especially Toos and Thriticosecale.
Conclusion: wheat genotypes were different in their response to Zn deficiency and Zn supply. Thriticosecale and Toos were the most Zn efficient genotypes, whereas Durum and C75-5 were the most responding to Zn supply. So, without considering these differences, accurate fertilizer recommendation cannot be achieved. For organic farming and low input agriculture systems in regions similar to this experiment location (Torough Station), Thriticosecale and Toos could be suggested. However, for improvement of wheat grain yield and achieve desired quality in calcareous soil, most of the time, it is necessary to use the Zinc fertilizers.
J. Givi
Abstract
In addition to qualitative and quantitative land suitability evaluation, economical evaluation can be carried out as well, based on net or gross benefit per surface area unit. The present research was done to evaluate land suitability, qualitatively and economically,, by different methods for irrigated ...
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In addition to qualitative and quantitative land suitability evaluation, economical evaluation can be carried out as well, based on net or gross benefit per surface area unit. The present research was done to evaluate land suitability, qualitatively and economically,, by different methods for irrigated maize, wheat, potato and barley in Shahrekord area. In this regards, qualitative land suitability class was determined by matching land characteristics with the studied crops growth requirements, using simple limitation method and ALES program. Economical land suitability evaluation was carried out, using "internal rate of return", "gross profit", "net present value" and "benefit/cost ratio" methods which are included in the ALES program. The results showed that qualitative suitability class in all of the studied land units for irrigated maize, wheat and barley is S2 and for irrigated potato in 73% of the units is S2 and in 27% of them is S3. As the "net present value" method is used, % 73 and % 27 of the land units are classified as S2 and S1, respectively for all of the studied crops. For wheat and maize, all of the land units are classified as S1, as gross profit, benefit/cost ratio and internal rate of return methods are used. For potato and barley, using gross profit and internal rate of return methods, % 73 and % 27 of the land units are classified as S2 and S1, respectively and as the benefit/cost ratio method is used, economical land suitability class in all of the land units is S1.
Mahdi Delghandi; Saeid Boroomand Nasab
Abstract
Field experiments for quantifying optimal breeding strategies are time-consuming and expensive. Crop simulation models can provide an alternative, less time-consuming and inexpensive means of determining the optimum breeding strategies. These models consider the complex interactions between weather, ...
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Field experiments for quantifying optimal breeding strategies are time-consuming and expensive. Crop simulation models can provide an alternative, less time-consuming and inexpensive means of determining the optimum breeding strategies. These models consider the complex interactions between weather, soil properties and management factors. CERES-Wheat is one of best models which can simulate the growth and development of wheat. Therefore, in present paper DSSAT 4.5-CERES-Wheat was evaluated for predicting growth, phenology stages and yield of wheat (cultivar of Chamran) for Ahwaz region. For this purpose, one Experimental research was designed at the experimental farm of the Khuzestan Agriculture And Natural Resources Research Center (KANRC), located at Ahwaz in 2010-2011 growth season. Using results of this research and two another research, CERES-Wheat model was evaluated. Results of evaluation showed that most and less NRMSE were abtained for simulation of maximum Leaf Area Index (6%) and phenology stages (2%), respectively. Therefore, it can conclude that CERES-Wheat is a powerful model in order to simulation of growth, phenology stages and yield of wheat.
Ahmad Gholamalizadeh Ahangar; B. Kermanizadeh; S.K. Sabbagh; A. Sirousmehr
Abstract
This investigation was conducted in order to evaluate the direct effects of organic and bio - fertilizers on yield components of two native wheat cultivars, Bolani and cross - Bolani. The experiment conducted as a factorial in a completely randomized design with three replications. Treatment includes ...
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This investigation was conducted in order to evaluate the direct effects of organic and bio - fertilizers on yield components of two native wheat cultivars, Bolani and cross - Bolani. The experiment conducted as a factorial in a completely randomized design with three replications. Treatment includes fertilizer factor: vermicompost (F1), vermicompost + compost (F2), vermicompost + mycorrhiza (F3), compost + vermicompost + mycorrhiza (F4), compost (F5), mycorrhiza + compost (F6), mycorrhiza (F7) and control (no fertilizer application F8) and cultivar factor includes two cultivar Bolani (C1) and cross - Bolani (C2). The results showed that the interaction effect of combined treatments (F7C2) of high yield (1.13 g.pot-1) obtained. The treatment combination (F7C2) of (0.355) was highest harvest index. The high correlation between weight per plant with plant height, spike length, grain yield and harvest index were observed. Generally the combined application of vermicompost and mycorrhiza cultivar cross - Bolani is more suitable for grain production.
Abstract
Biofertilizers can be used as complementary in sustainable agriculture. The main target of this study was effects of nitrogen and phosphorus fertilizers and chemical fertilizers on wheat yield and yield components in two soil types. Experimental design as the factorial formed completely randomized design ...
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Biofertilizers can be used as complementary in sustainable agriculture. The main target of this study was effects of nitrogen and phosphorus fertilizers and chemical fertilizers on wheat yield and yield components in two soil types. Experimental design as the factorial formed completely randomized design with three replications was executed. Experiment Factors included two soil types (sandy loam and clay loam) and 9 fertilizer treatments. For the experiment implementation used 100 gram per hectare of Nitrokara (Azorhizobium caulinodans) and Barvar 3 phosphorus (Pseudomonas putida, Strain P13, Pantoea agglomerans, Strain P5 and Pseudomonas putida, Strain MC1) biofertilizers in single and combined forms by method of seed inoculation. The results showed positive effects of clay loam type and inoculation of two biofertilizer types especially in the presence of 50% of chemical fertilizers on shoot dry weight, root dry weight, number of grains per spike, 1000 grain weight and wheat grain yield. The results showed 100% chemical fertilizer and phosphorus biofertilizer in combination with 50 % of chemical fertilizer treatments showed the highest effect in most characteristics and control treatment showed the lowest effect in this characteristics. Nitrokara biofertilizer in combination with 50% of chemical fertilizer had the maximum 1000 grain weight. Phosphorus biofertilizer in combination with 50% of chemical fertilizer on wheat yield and yield components showed a better effect than Nitrokara biofertilizer.The results of this research showed by combining biological and chemical fertilizers can reduce consumption of chemical fertilizers.
Z. Lotfi Arpachaei; Abazar Esmali; kazem hashemimajd; n n
Abstract
In modern agriculture, the preparation of soil fertility map seems to be necessary to plan for appropriate using of fertilizers for crops. This study was conducted to prepare a distinct map for evaluating soil fertility according to soil chemical properties in 136 soil samples of Ardabil plain in Ardabil ...
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In modern agriculture, the preparation of soil fertility map seems to be necessary to plan for appropriate using of fertilizers for crops. This study was conducted to prepare a distinct map for evaluating soil fertility according to soil chemical properties in 136 soil samples of Ardabil plain in Ardabil province. To achieve this purpose, the available K and P, total N, EC, pH and organic matter of soil were mapped using geostatistical Kriging estimator into Geographic Information System (GIS) by ArcGIS9.3 software. The Analytical Hierarchy Process (AHP) was used for weighting soil fertility factors as the input data. Then a membership functions was defined for each factor by factorial scoring and the map of soil fertility was prepared and classified for wheat and potato by using AHP technique into GIS program. The results showed that 74.84, 3.59, 19.3 and 2.32 percentage of lands for wheat cropping were classified based on soil fertility into groups of weak, moderate and suitable, respectively while for potato it was 24.88, 27.57, 7.19 and 40.34 percentage, respectively. As a final result, this type of distinct soil fertility map for different crops could assist us to manage the appropriate using of lands and fertilizers.
H.R. Motaghian; A. Hosseinpour; jahangard mohammadi; Fayez Raiesi
Abstract
Rhizosphere is a small zone and has quite different chemical, physical and biological properties from bulk soil. This research was conducted to investigate the availability and fractionation of copper in the wheat rhizosphere and bulk soils by using rhizobox at greenhouse conditions. Three seeds of wheat ...
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Rhizosphere is a small zone and has quite different chemical, physical and biological properties from bulk soil. This research was conducted to investigate the availability and fractionation of copper in the wheat rhizosphere and bulk soils by using rhizobox at greenhouse conditions. Three seeds of wheat were plant in the rhizobox. After 8 weeks, plants were harvested and rhizosphere and bulk soils were separated. Total organic carbon (TOC), dissolved organic carbon (DOC), microbial biomass carbon (MBC) and available Cu (by using 7 chemical procedures) and Cu-fractions were determined in the rhizosphere and bulk soils. The results indicated that TOC, DOC and MBC in the rhizosphere were increased significantly (p
M. Ghaemi Baygi; mahmood raeini; M. Mousavi Baygi
Abstract
Evapotranspiration is one of the important elements of the hydrologic cycle in agricultural projects. Energy balance (the bowen ratio) is a method for estimating evapotranspiration of plant which is based on measurements of temperature and humidity gradients in two different heights of a plant. An experiment ...
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Evapotranspiration is one of the important elements of the hydrologic cycle in agricultural projects. Energy balance (the bowen ratio) is a method for estimating evapotranspiration of plant which is based on measurements of temperature and humidity gradients in two different heights of a plant. An experiment was conducted in agriculture faculty of Ferdowsi university of Mashhad by using three Lysimeter to estimate evapotranspiration of Gascogne wheat and the resulting were compared with direct method. Required data for measuring the amount of evapotranspiration using energy balance method was obtained throughout plant phenology with one hour intervals using energy balance (model 5200 – DIK) estimation device of evapotranspiration was daily calculated. The rate of daily evapotranspiration that obtained by using energy balance method amounted to 2.4 mm which is in a high correlation (0.98) with the Laysimeter result that was 2.4 mm. The range of Bowen ratio changes was between -1.5 to 1.9 during the day which the negative values occurs after sunset that is the sensible heat flux begins to decrease. The value of Boven ratio gradually increase so that it's maximum value between 8 AM to 9 AM, and then followed a decreasing trend until the afternoon.
E. Iranshahr; E. Sepehr
Abstract
A factorial completely randomized design experiment with three replications was carried out in greenhouse to evaluate the phosphorus (P) acquisition and utilization efficiency of 20 wheat genotypes in a river sand fertilized with rock phosphate (RP) and soluble P (PS). Results showed significant differences ...
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A factorial completely randomized design experiment with three replications was carried out in greenhouse to evaluate the phosphorus (P) acquisition and utilization efficiency of 20 wheat genotypes in a river sand fertilized with rock phosphate (RP) and soluble P (PS). Results showed significant differences in shoot dry weight (SDW), shoot P concentration, shoot P content, P acquisition (PACE), P utilization (PUTE) and P efficiency. Marvdasht and Hamun with 8.3 and 5.6 g dry weight showed the highest and lowest response to soluble P fertilizer application, respectively. The average of PACE for all genotypes was 0.04 which Azadi and Karaj1 were the most and least efficient in P acquisition compared to other genotypes. PUTE ranged from 0.6 (Azadi) to 1.12 (Moghan 1) with the average of 0.82 (RP) and 0.31 g DW mg-1 P (PS). Among wheat genotypes, Karaj 1 (4.5%) and Azadi (14.5%) showed the lowest and highest P efficiency, respectively. There was no correlation (R2=0.18) between P efficiency and shoot P concentration of genotypes, but the relationship between P efficiency and shoot P content was highly significant (R2=0.77).
S. Akhavan; M. Shabanpour; M. Esfahani
Abstract
In order to study the effect of soil compaction on root and shoot growth of wheat plants (Shahriar variety), a greenhouse pot experiment was conducted in Guilan University. The study design was factorial with completely randomized in three replications. Treatments included three compaction levels; (normal ...
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In order to study the effect of soil compaction on root and shoot growth of wheat plants (Shahriar variety), a greenhouse pot experiment was conducted in Guilan University. The study design was factorial with completely randomized in three replications. Treatments included three compaction levels; (normal compaction, compaction of ten percent and twenty percent) and two type of soil texture (clay and sand) will include 18 pots. Soil mechanical resistance index measured with the device influence the resistance gauge significant differences among treatments indicated. Root and shoot traits measured included plant fresh weight and total shoot dry weight, leaf dry weight (LDW), stem dry weight (SDW), root fresh weight (RFW), root dry weight (RDW), leaf area (LA), root area (RA), root volume (RV), root length (TL), root dry weight ratio of shoots, leaf area to root ratio (LA/RA), root length density (RLD), root surface area density (RSD), root mass density (RMD), dry root mass density (DRMD) and nitrogen content of roots, significant difference in the levels indicated treatments. The results showed that increasing the compaction of soil are affected characteristics related to the shoot and root of wheat plants, and twenty percent of the compaction (influence resistance 1200 KPa in the clay soil and 762.76 Kpa in the sandy soil) is limited roots and shoots growth than the natural soil.
