Soil science
R. Motalebifard
Abstract
Introduction
Grape is one of the most important horticultural products in the world and Iran which has been noticed due to its cultivation area, high economic and nutritional values. Annually, about 68 million tons of grape are produced in the world. Iran, with 309,000 ha cultivation area and ...
Read More
Introduction
Grape is one of the most important horticultural products in the world and Iran which has been noticed due to its cultivation area, high economic and nutritional values. Annually, about 68 million tons of grape are produced in the world. Iran, with 309,000 ha cultivation area and about 3.3 million tons share of production, is the 11th largest producer of this fruit in the world. Recent studies have shown that plant nutrition and soil fertility have significant effect in the reduced yield quality in the grape fields of our country. Plant nutrition as an influential factor is a function of the interaction of nutrients and environmental conditions. Assessing the nutritional status of plants is necessary to achieve the relationship between nutrients availability in the soil, the amount of elements in the plant and yield. Plant analysis method is used to optimize fertilizer application and diagnose plant nutrition disorders. The plant analysis method is useful for evaluating plant nutrition if an appropriate method to be used to diagnose and interpret the results. Tissue nutrient status can be diagnosed by the Critical Value Approach (CVA), the Diagnosis and Recommendation Integrated System (DRIS), and Compositional Nutrient Diagnosis (CND). Only DRIS and CND provide nutrient imbalance indexes, although no threshold value has been validated yet for diagnostic purposes. CND method expresses interactions by considering the ratio of one element to all elements. In this method, high and low functional groups are separated with great accuracy with the help of mathematical and statistical methods and the application of the cumulative function of variance ratio of nutrients and chi-square distribution function. A critical CND imbalance index was derived from the chi-square distribution function. Due to the importance of grape production in the country and the lack of required nutritional norms, this study was conducted to investigate the nutritional status of grape fields using the CND method.
Materials and Methods
In order to evaluate the nutritional status of grape fields in the Hamedan province, this study was conducted in the cropping years of 2017-2020. Every year, 40 different orchards were selected in each of the regions. The orchards were selected in such a way that they had different ranges of yield and soil properties. A database containing laboratory and field data was created for each grape field. The geographical location was recorded for the orchards. In each orchard, plant (leaf) samples were prepared and analyzed based on suitable laboratory methods. At the end of the season, the yield and its components were determined by visiting each orchard. Concentrations of nitrogen, phosphorus, potassium, calcium, magnesium, iron, zinc, manganese, and copper were measured in grape leaves. The project database was completed and CND indices were calculated for each nutrient element. The selected grape fields were divided into two groups with high and low yield based on yield. The CND norms and indexes were computed according to computation steps of Parent and Dafir. The Cate–Nelson ANOVA procedure was used to partition yield data between two groups by maximizing the between-groups sums of squares to determine the threshold values for CND indexes required to compute the critical CND r2 value. We used 83 observations for developing the nutrient norms.
Results and Discussion
The results of the indices calculated by the method of CND showed that the grape fields were deficient in nitrogen and potassium among the macronutrients and iron and manganese among the micronutrient elements. There was a correlation (0.25) between nutritional balance index and yield that was significant at 1 percent probability level. Potassium index was negative in 83% of low yield orchards. After potassium, nitrogen had a negative index in 58% of medium and low yield orchards. Phosphorus had the most positive index among macronutrients and was positive in most orchards. Among the micronutrients, manganese, iron, and zinc indices were negative in 59%, 49% and 73% of the orchards, respectively. The presence of calcareous conditions in the soils of the region can be the reason for this deficiency. The boron index was positive in some orchards and negative in some other orchards. Furthermore, in total, the index of unknown factors was negative in 41% of grape fields in Hamadan province.
Conclusion
The results indicated that management of evaluated orchards was not suitable and application of chemical fertilizers was unbalanced. The results of this study can be used in grape fields to increase yield and product quality. Therefore, it is recommended to use deficient elements in the fertilization program to improve yield.
Hassan Mir; Ahmad Gholamalizadeh Ahangar; Noshin Mir
Abstract
Introduction: Increasing the production rate became considerable for farmers in various ways. Modern technologies, such as biotechnology and nanotechnology could play an important role in increasing the production and improving the quality of agricultural products. Research into the direct application ...
Read More
Introduction: Increasing the production rate became considerable for farmers in various ways. Modern technologies, such as biotechnology and nanotechnology could play an important role in increasing the production and improving the quality of agricultural products. Research into the direct application of nanotechnology into agriculture is set to increase in the future. One of the most remarkable plant growth factors is its nutrition. Titanium plays a beneficial role in increasing and stimulating plants growth. Titanium's usage in nutrition solution or spraying on the plant will increase the biomass and growth of different plant species. With respect to Nano technology enhancement in recent years the application of nano-particles is increasing. All the positive effects of titanium dioxide depend on its ability to absorb light and the main disadvantages of this combination are the low ability to absorb visible light from the sun and absorbing more UV light. It is possible to improve its effectiveness due to the high proportion of sunlight in the visible range by absorbing the visible light of nano-particles. To achieve this goal a layer of color will be added on the surface of the nanoparticles, which is called the nanoparticle sensitization by color. Due to the absorption of light by titanium dioxide nano-particles, especially ultraviolet radiation, it is assumed that the creation of a color layer on these nano-particles increases the antibacterial and fungal properties of these nanoparticles. As a result, the goal of this experiment is to investigate the possible increase in light absorption and increase the yield of the sorghum plant by titanium dioxide nano-particles of Dye-Sensitized, which, some of the parameters were investigated by treating the seeds of the plant with both nanoparticles.
Materials and Methods: This research was performed in three replications in a completely randomized design with factorial arrangement and with 12 treatments containing 6 concentrations of titanium dioxide nano-particles (0, 1, 10, 50, 100 and 500 mg.L-1), 6 concentration of titanium dioxide nanoparticles of Dye-Sensitized (0, 1, 10, 50, 100 and 500 mg.L-1). Fresh and dry weight of plants, plant nutrients content (Phosphorus, Potassium, Manganese, and Zinc), activity of ascorbate peroxidase and guaiacol peroxidase and chlorophyll content parameters have been measured.
Discussion and Results: The saffron compounds have significant peaks in the UV-Vis spectrum. The spectrum of titanium dioxide nanoparticles has a specific peak in the ultraviolet range (Area between wavelengths of 200-400 nm) however there is no trace of absorption in visible areas. The spectrum of the saffron solution has two identifiable peaks at 328 and 258 nm, and a double peak at 466 and 442 nm. The observed peak at 258 nm is related to the combination of Picrocrocin, which is the same colorless bitter substance found in saffron. The dual peaks range between 400-500 nm and the peak appearing at 328 nm are related to the carotenoids found in saffron. Crocin also has similar peaks which are likely to be overlapping with trans-isomeric peaks and not separable. The Spectrum of titanium dioxide nano-particles covered with saffron color also represents two peaks at 322 and 260 nm, and a peak at 430 nm with a specific shoulder at 458 nm. What comes from the comparison of two saffron peaks alone and saffron coated on titanium dioxide nano-particles is that the Crocin molecules contained in saffron are attached to nano-particles. According to the results, dry weight and enzymatic activity of Guaiacol peroxide and Ascorbate peroxide showed a significant increase compared to the control and had the highest performance respectively at concentrations of 10, 100 and 500 mg.L-1of titanium dioxide nano-particles of Dye-Sensitized, and showed 1.25, 2.7 and 3.28 fold. The amount of plant nutrients such as phosphorus, potassium, manganese, and zinc at concentrations of 10, 100, 500 and 50 mg.L-1titanium dioxide nanoparticles of Dye-Sensitized had a 72.34, 42.85, 73.95 and 28.17 percent increase, except fresh weight and chlorophyll a. Chlorophyll a at a concentration of 500 mg.L-1of both nano-particles showed the highest amount, but the fresh weight, unlike other parameters, showed the best performance with normal nanoparticles.
Conclusion: It seems that these nano-particles, by coloring, intensify light-related reactions compared to normal nano-particles, which results in better performance.
Majid Basirat; Hassan Haghighatnia; Seyed Majid Mousavi
Abstract
Introduction: Fertilizer recommendation in orchards based on soil testing is not accurate because findings showed that there is not significant correlation between nutrients concentration in the soil and plant. Therefore, studying the nutritional status in orchards is usually based on the plant testing. ...
Read More
Introduction: Fertilizer recommendation in orchards based on soil testing is not accurate because findings showed that there is not significant correlation between nutrients concentration in the soil and plant. Therefore, studying the nutritional status in orchards is usually based on the plant testing. In order to evaluate the nutritional status ofplants, different methods, such as Compositional Nutrients Diagnosis (CND), Diagnosis and Recommendation Integrated System (DRIS), Deviation from Optimum Percentage (DOP), Critical Value Approach (CVA) and Sufficiency Range Approach (SRA) were used. In the CND method, a determination coefficient measured which is considered as the relative superiority of this method to the others. Generally, through the CND method, a correct perception on nutritional status of plantsmay be obtained.
Materials and Methods: The nutritional status of orange orchards, Valencia cultivar, in south of Fars province (Darab town) was studiedusing the compositional nutrient diagnosis and multivariate statistical analysis methods. For this, 80 orange orchards, Valencia cultivar were selected and 30 trees in each orchard were signed. Plant samples were taken from the selected trees in the proper session and concentration of N, P, K, Ca, Mg, Mn, Zn, Fe, Cu and B weremeasured using the standard methods. Then the average yield was measured atharvest. Based on the CND method, total concentration of the nutrients in the plant was considered as a variable (Sd) plus a residual portion (Rd) that "d" is defined as the number of nutrients in the equation and Rd is defined as the residual value. Which sum of the equation equals 100 and it is based on percent. The residual/un measured nutrients and estimated by using the equation of " Rd = 100- (N+P+K+…)". Thereafter, by using the standard equations, which they were perfectly explained and presented in the material and methods section, the geometric mean of nutrients, nutrients index, nutrient balance index, and average yield and finally the reference norms were determined. In addition to the CND method, by using the Multivariate Statistical Analysis and PrincipalComponent Analysis methods, the effective and important nutrients in the yield were determined and also, ability of the CND method was evaluated. The SPSS software was used for variance analysis the data.
Compositional nutrient diagnosis (CND) analysis and multivariate analysis methods are used to study the nutritional diagnosis of Valencia orange orchards in south of Fars province. 80 valencia orange orchards were selected in the region and in each of them, 30 uniform trees were marked and sampled were taken in proper time and referenced method. Leaf elemental compositions and mean yield also were measured from selected trees for each orchard. Data analysis divided all orchards into two low and high yield groups.
Results and Discussion: The results showed that 11 orchards were as high yielding group and 69 orchards were as low yielding group and the average of optimum yields, 113 Kg tree-1, was determined as the yield goal. By using the average of measured nutrients norms for the high yielding community the concentration of the 10 studied elements was obtained which comprised: N 3.00± 0.18; P 0.17± 0.01; K 1.37± 0.12; Ca 3.32± 0.78; Mg 0.36±0.07; Mn 23± 3.35; Zn 17.3± 2.3; Fe 75± 7.3; Cu 7.81± 1.44; B 76± 19.4. Through comparison with the obtained reference norms of optimum yielding orchards, more than 50% of the studied orchards had lower N, Ca and Mn content than the obtained norm and B concentration in the high yielding group was more than 50% less than the low yielding group. Generally, the results of Multivariate Statistical Analysis and PrincipalComponent Analysis showed that N, Ca, Fe and Zn had the highest effect in changes of yield.
Conclusion: Resultsof this work showed that 13% of the studied orchards were in the high yielding group and 86% of themwere in thelow yielding group which shows the imbalance nutritional condition in the studied region. The positive effect of N and Ca on the yield may be due to the dilution effect which these nutrients can reduce the B toxicity. Abundance of Mn deficiency in the studied orchards may be due to the high concentration of Zn and Fe in the plants and antagonistic relations may be considered as the main reason. Multivariate statistical analysis methods may be used as an important tool to study the nutritional conditions of plants. Dominant percentage of the studied orchards showed low yield which may be due to the B toxicity which probably N and Ca application may be alleviated the negative effect of this element.
Sareh Nezami; Mohammad Jafar Malakouti
Abstract
Introduction: Phosphorus (P) and zinc (Zn) fixation by soil minerals and their precipitation is one of the major constraints for crop production in calcareous soils. Recent Studies show that root exudates are effective for the extraction of the large amounts of nutrients in calcareous soils. A part of ...
Read More
Introduction: Phosphorus (P) and zinc (Zn) fixation by soil minerals and their precipitation is one of the major constraints for crop production in calcareous soils. Recent Studies show that root exudates are effective for the extraction of the large amounts of nutrients in calcareous soils. A part of the root exudations are Low Molecular Weight Organic Acids (LMWOAs). LMWOAs are involved in the nutrients availability and uptake by plants, nutrients detoxification, minerals weathering and microbial proliferation in the soil. At nutrients deficiency conditions citric and oxalic acids are released by plants root in large quantities and increase nutrient solubility like P, Zn, Fe, Mn and Cu in the rhizosphere. These components are the large portion of the carbon source in the soil after exudations are mineralized by microorganisms, quickly. In addition, soil surface sorption can affect their half-life and other behaviors in the soil. In order to study the effect of oxalic and citric organic acids on the extraction of phosphorus and zinc from a calcareous soil, an experiment was conducted.
Materials and Methods: Studied soil was calcareous and had P and Zn deficiency. Soil sample was collected from A horizon (0-30 cm) of Damavand region. 3 g of dried soil sample was extracted with 30 ml of oxalic and citric acids extraction solutions at different concentrations (0.1, 1 and 10 mM) and different time periods (10, 60, 180 and 360 minutes) on an orbital shaker at 200 rev min-1.The soil extracts then centrifuged for 10 minutes (16000g). After filtering, the pH of the extractions was recorded and then phosphorus, calcium and zinc amounts were determined. Soil extraction with distilled water was used as control. Each treatment was performed in 3 replications. Statistical analysis was performed with ANOVA test followed by the Bonferroni method significant level adjustments due to multiple comparisons.
Results and Discussion: The results of variance analysis showed that the effect of different concentrations of organic acids at various times on the pH of extractions was significant at 1% level. Low concentrations of organic acids at various times had no effect on the pH of soil extractions compared to control, but organic acids at 10 mM concentration increased the pH of extractions. This high pH amount was related to the organic acid mineralization and consumption of H+ by microorganisms in the soil. The results of variance analysis also showed that the effect of different concentrations of organic acids at various times in the extraction of Ca from the soil was significant at 1% level .Citric acid extracted higher Ca from the soil compared to oxalic acid. The maximum extracted Ca was observed at 10 mM concentration of citric acid at 10 minutes of shaking time. Extracted Ca at 0.1 and 1 mM concentrations of both organic acids was almost the same at all the times. The higher extraction of Ca with citric acid was due to the Ca precipitation as oxalate. The analysis of variance for P showed that the effect of different concentrations of organic acids at various times was significant at the 1% level. Extracted P by oxalic acid was more than citric acid .The highest amount of P was obtained by 10 mM concentration of oxalic acid at 360 minutes. The amounts of extracted P by both organic acids at 0.1 and 1 mM concentrations were similar to control. Citric acid at 10 mM concentration also released lower P compared to other concentrations and control. More P extraction of oxalate than citrate was due to the Ca-oxalate formation and P release from calcium phosphate in calcareous soil. Different concentrations of organic acids at different time periods had no effect on Zn extraction from the soil and the amount of extracted Zn by organic acids was lower than control.
Conclusion: Organic acids at 10 mM concentration were effective in Ca and P extraction from the soil but had no significant effect on the Zn extraction. It seems that organic acid more than 10 mM concentrations is required for Zn extractionfrom from the calcareous soils. The type and concentration of Organic acids, soil type, shaking time and experimental conditions are important factors that affect the obtained results.
Z. Sharifi; Mohammad Taaher Hossaini
Abstract
Introduction: the use of municipal solid waste (MSW) compost in agriculture as a soil conditioner is increasing day by day because of its positive effects on biological, physical, and chemical soil properties. However, some of the composts because of contamination with heavy metals and other impurities ...
Read More
Introduction: the use of municipal solid waste (MSW) compost in agriculture as a soil conditioner is increasing day by day because of its positive effects on biological, physical, and chemical soil properties. However, some of the composts because of contamination with heavy metals and other impurities can have deleterious effects on groundwater quality, agricultural environment, food chain, plant growth and activity of soil microorganisms. Therefore, this study was conducted to investigate the physical and chemical properties, fertilizing potential and heavy metal polluting potential of two types of municipal solid waste composts with processing time between 4 to 8 years (type A) and between1 to 4 years (type B) produced in Sanandaj city with the aim of using it as an organic fertilizer.
Materials and Methods: Sanadaj city, the center of Kurdistan province, with a population of about 335,000 is located in the west of Iran. The current solid waste generation from the city is about 320 t/day, which are not separated at source of generation. About 200 t of the total produced wastes are composted using an open windrows system at the Sanandaj MSW Composting Plant, which is located in 10 km of Sanadaj-Kamiaran road and the rest are disposed at the landfill site. The compost manufactured by the composting plant has been collected around it in two different locations. The first belonges to the product of 2004-2008 (type A) and the second belonges to the product of 2009-2013 (type B). Till now, due to lack of quality information associated with these products, they have remained unused. Therefore, in this study, we sampled 3 samples composed of six subsamples (each containing 2 kg) from the products in March 2013. The samples were analyzed to determine the physical properties (including undesirable impurities, initial moisture content, particle size distribution, particle density, bulk density (ρb), porosity, and maximum water holding capacity), and the chemical properties (including organic carbon, ash content, pH and salinity) and total amounts of N, P, Ca, Mg, K, Na, Mn, Fe, Cr, Zn, Pb, Ni and Cd using standard methods.
Results and Discussion: The results showed that bulk density, ash content, and the amounts of elements based on the dry weight of compost increased with composting time, however particle size decreased. It is well known that dry bulk density increased with composting time as ash content increased and particle size decreased by decomposition, turning and screening. The decreases of particle size with composting time cause an enrichment of metals based on the dry weight of compost. It is likely due to solubilization of metals in waste by organic acid produced during the microbial decomposition of organic matter and their subsequent adsorption on finer particles due to the higher surface area and the higher ion exchangeable capacity. The evaluation of the fertilizing potential of the surveyed composts by comparing their properties with different standard sets showed that the both composts under test in this study were failed to meet the standard permissible limits with regard to glass content (on average, 21.7 times over the permissible limit), gravel content (on average, 1.4 times over the permissible limit), lead content (on average, 1.6 times over the permissible limit), and salinity content (on average, 1.4 times over the permissible limit). Furthermore, compost type B also failed to meet the standard permissible limits with regard to initial moisture content (on average, 1.4 times over the permissible limit) and ρb (0.2 gcm-3, less than permissible limit) for agricultural purposes. The results showed that excessive amount of glass impurity bigger than 2 mm, salinity and lead contents are the major problems in the use of the composts for agricultural purposes. It should be noted that according to the maximum permissible limit of lead (150-300 mg kg-1) for compost C1 quality class described by Australian standard; both the composts can be used as fertilizers or soil amendments. In order to eliminate glass impurity, remediation approaches such as fine milling and pelleting is needed to disguise the residual glasses and render it as relatively harmless. A feasible approach to eliminate these problems is probably physical fractionation of the studied composts. It allows us to assess the distribution of nutrients and contaminants values in the different physical fractions of the composts, which is useful to detect and to eliminate of the particle sizes which are the responsible for these impurities.
Conclusion: The assessment of MSW-based compost for use in agricultural soil as fertilizer or conditioner is a sustainable recycling practice owing to its nutrient content and its positive effects on soil physico-chemical properties. Thus, we evaluated the fertilizing potential of two MSW composts produced in Sanandaj city for agricultural purposes. Altogether, the results of the study showed that excessive amount of glass impurity bigger than 2 mm and salinity were the major problems in the use of the composts for agricultural purpose. As a result, the quality of the surveyed composts was not suitable for agricultural purposes without appropriate remediation of these restrictions.
A. Gholami; A. Ansouri; H. Abbas dokht; A. Fallah Nosrat Abad
Abstract
Introduction: Sulfur is the key element for higher crops and plays an important role in the formation of proteins, vitamins, and enzymes. It is a constituent of amino acids such as cysteine and methionine, which act for the synthesis of other compounds containing reduced sulfur, such as chlorophyll and ...
Read More
Introduction: Sulfur is the key element for higher crops and plays an important role in the formation of proteins, vitamins, and enzymes. It is a constituent of amino acids such as cysteine and methionine, which act for the synthesis of other compounds containing reduced sulfur, such as chlorophyll and utilization of phosphorus and otheressential nutrients.Deficiency of this nutrient in soil is usually compensated by using chemical fertilizers. However, these fertilizers have harmful effects on the environment and decrease the quality of the agriculture products. Therefore, biological fertilizers are more useful for using in agricultural ecosystems.Sulfurshould be addedto the soil, usually in a reduced form such as elemental sulfur. Use of S oxidizers enhances the rate of natural oxidation of S and speeds up the production of sulfates and makes them available to plants consequently resulting in an increased plant yield. The role of chemolithotrophic bacteria of the genus Thiobacillus through oxidation process in the soil is usually emphasized. Sulfur oxidation is the most important step of sulfur cycle, which improves soil fertility. The result is formation of sulfate, which can be used by the plants, while the acidity produced by oxidation helps to solubilize nutrients in alkaline soils. These bacteria can solubilise the soil minerals through the production of H2SO4 that reacts with these non-soluble minerals and oxidised them to be available nutrients to the cultivated plants. Arbuscular MycorrhizalFungi isan important component ofthe microbiota, mutualistic symbioticsoilfungithatcolonizesthe rootsofmost cropplants.The AM symbiosis involves an about 80% of land plant species and 92% of plant families. They have theability to enhance host uptake of relativelyimmobile nutrientsparticularly phosphorus (P) andzinc (Zn),Manganese (Mn) andiron(Fe).Arbuscular mycorrhizal fungi increased plant uptake of phosphorus, nitrogen and water absorption. Inoculation withthesefungihas increased the yield of numerous field-grown crops.
This study was aimed to evaluate the effects of thiobacillus bacteria and sulfur application on soil pH, and also their interactions with mycorrhizal fungi in order to improve nutrients uptake and grain yield of maize under alkaline soil condition.
Materials and Methods: Treatments arranged as factorial experiment were based on RCBD with three replications. Treatments consisted of mycorrhizal inoculation: inoculated (m1) and non-inoculated (m0), thiobacillus in two levels of inoculated (t1) and non-inoculated (t0) and three levels of sulfur (S0: 0 kg.ha-1, S1: 250 kg.ha-1 and S2: 500 kg.ha-1). Four-row plots were prepared with row width and intra-row space of 60 and 20 cm, respectively. Seeds of maize (Zea Mays, Sc:647) were surface sterilized in a 10% (v/v) solution of hydrogen peroxide for 10 min, were rinsed with sterile distilled water. Before sowing, 300 kg of urea per hectare were applied according to the results of soil analysis. In order to facilitate oxidation of sulfur to sulfate form, , S was applied and thoroughly mixed into top 30 cm of soil 30 days before sowing. One week before sowing, thiobacillus (Thiobacillus thiooxidans) was inoculated. Inoculum of AM fungus Glomus intraradices, were added to soil just before planting at about 2 centimeters below seed sowing dept. To measure Arbuscular Mycorrhizal colonization, root plants collected one week before harvesting, cleared in 10% KOH at 80˚C for 2 h, and then acidified in 1% HCL for 60 min. Then the cleared roots were stained in a solution of Trypan blue. For nutrient analysis, the following procedure was applied. Zn, Fe, S, and P were determined by Inductively Coupled Plasma-atomic emission spectrometry apparatus. For this purpose, ash of seed samples was prepared at 500-550 degree of Celsius and then 5 ml of HCl 37% was added and with dionized water to reach to 50 ml. Kjeldahl method was used to determine nitrogen. Analysis of variance was performed on all experimental data and means were compared using the least Significant Differences (LSD) test with SAS software. The significance level was p>0.05 unless stated otherwise.
Results and Discussion: Results showed sulfur application increased significantly the amount of S, P, N, Fe, Zn, shoot dry weight and leaf chlorophyll of maize. With increasing Sulfur, sulfur concentration in plant shoot increased with linear trend. The highest S concentration was obtained with 200 mg.kg-1 S and the lowest amount was obtained from control plots. Applications of 50, 100, 150 and 200 mg.kg-1 S increased P content about 0.45, 3.91, 4.74 and 5.56 %, respectively. The highest N contentwas obtained with 100 mg.kg-1 S. The thiobacillus significantly increased P, Fe, Zn anddecreased root colonization and soil pH compared to control. Thiobacillus bacteria increased shoot P only with application of 100 mg.kg-1 S. Mycorrhizal inoculation increased the amount of N, P, S, Fe, Zn, shoot dry weight and root colonization. Inoculation with G.intra and G.mosseae increased shoot P content about 4.18 and 3.34% in comparison with the control plots. Single or combination of sulfur and thiobacillus had a negative impact on the root colonization. Based on the results it seems that sulfur, thiobacillus and mycorrhiza in alkaline soils improved crops nutrition and growth. S application and thiobacillus interaction on S concentration of maize shoot were significant. In condition of 0 or 50 mg.kg-1 S application, inoculation of thiobacillus is recommended. Also, the effects of mycorrhiza on P shoot was significant with no application of S.
H. R. Boostani; abdolmajid ronaghi
Abstract
Sewage sludge (SS) as a source of required plant nutrients has been utilized in many countries for crops production. for investigation of SS application affect in compared to chemical fertilizer treatment (F), on dry matter yield (DMY) and concentration of some macro and micro nutrient in corn, a greenhouse ...
Read More
Sewage sludge (SS) as a source of required plant nutrients has been utilized in many countries for crops production. for investigation of SS application affect in compared to chemical fertilizer treatment (F), on dry matter yield (DMY) and concentration of some macro and micro nutrient in corn, a greenhouse experiment (5 × 3 factorial) arranged in a completely randomized design with three replicates was conducted. The first factor included SS levels (0, 10, 20, 40 and 80 gr kg-1 soil) and the second factor was soil textural classes (clay loam, sandy loam and sandy). A chemical fertilizer treatment was also used to compare its affect with that of SS application levels on growth and chemical composition of corn. For comparison of applied SS levels (one factor) with chemical fertilizer treatment in each soil textural classes was used from a completely randomized design with six treatment and three replicates. The results indicated that addition of SS significantly increased DMY of corn in all textures. Application of SS significantly increased N, P, Fe, Zn, Cu and Mn concentration in corn aerial parts and nutrients deficiencies symptoms disappeared. Nutrients concentrations in corn plants did not reach to toxic levels even at high rates of SS application and concentration of Cd and Pb were negligible and not detectable in shoot corn. Based on nutrient deficiency in calcareous soils especially Zn and Fe, application of SS for contrasting with shortage of these elements can be effective way to eliminate these nutrients shortage. In general, application of SS was superior to chemical fertilizer treatment in increasing concentration of nutrients and DMY of corn. Prior to any SS recommendations the results of this experiment needs to be verified under field conditions.
