Hamidreza BEHRAVAN; REZA KHORASANI; Amir Fotovat; Abdol Amir Moezei; Mehdi Taghavi
Abstract
Introduction: Sugarcane cultivation has been revived in Khuzestan province of Iran since the 1960s and due to good results, it gradually began to grow from north to south of this region. Currently, sugarcane is cultivated in more than 100,000 hectares of the provinceand almost 25% of the country needs ...
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Introduction: Sugarcane cultivation has been revived in Khuzestan province of Iran since the 1960s and due to good results, it gradually began to grow from north to south of this region. Currently, sugarcane is cultivated in more than 100,000 hectares of the provinceand almost 25% of the country needs for sugar arebeing produced in this region. Sugarcane fields of Khuzestan province are mainly rich in lime percentage and poor in organic matter and phosphorus. Soil pH in this region of the country also is about 8-8.5 and phosphorus uptake by plants and phosphorus fertilizer efficiency in these soils (alkaline and calcareous soils) are expected to be low. The optimum use of phosphorus fertilizer and proper phosphorus uptake is essential for the quantitative and qualitative function of sugarcane plants. Due to the very low mobility of phosphorus in the soil, its uptake by plants such as sugar cane is affected by number of soil and plant factors (especially plant root characteristics). Changes in these factors can lead to a reduction or increase of P uptake by the crop.
Materials and Methods: Because of the role of organic compounds in the improvement of mobility and phosphorus uptake, the use of organic material has been considered in many types of research. Organic compounds can play a direct and indirect role in plant factors and in phosphorous uptake improvement. In this regard, a greenhouse pot experiment was conducted in 2016-2017 at Farabi Agro Industry Co, 35 km south of Ahvaz, Iran (48º 36' E, 30º 59' N). This research carried out by using three levels of humic acid (immersion of settes in three concentrations of 0, 0.3 and 0.5% of humic acid) as well as three levels of phosphorus fertilizer (triple super phosphate) 0, 50 % and 100% of the recommended amount in the region (250 kg/ha) in two different harvesting periods (45 and 90 days after planting). The experiment set up as a factorial, based on complete randomized design with three replicates. In this experiment, the effects of different levels of phosphorous fertilizers and humic acid on aerial part (shoot height, shoot dry weight), underground part (root length, root dry weight and root hair length), and also root CEC of sugar cane plant in two harvest times were studied. Finally, uptake and influx of phosphorus in different treatments were investigated.
Results and Discussion: As the results show, although the range of the changes was different, the use of humic acid could improve almost all of these factors. Shoot height, shoot dry weight in humic acid treatments showed a significant increase in both harvests compared to non-used humic acid treatments and also in phosphorus fertilizer treatments as the fertilizer levels rose. These results show that humic acid can increase the uptake of phosphorus from the soil reservoir (treatments without phosphorus fertilizer) and source of soil and phosphorus fertilizer (phosphorus fertilizer treatments). The underground plant parts have also shown similar results. Root length and root dry weights have also been shown positive results in humic acid treatments. Therefore, an increase in phosphorus uptake in non-use phosphorous fertilizer treatments or phosphorous fertilizer treatments, along with humic acid, relative to non-humic acid treatments could be explained. The humic acid application seems to increase the uptake capacity of phosphorus from soil and fertilizer sources by increasing root length and root dry weight. In addition, the use of humic acid in alkaline soil can increase the solubility of phosphorus in water and therefore the phosphorus uptake by the roots of the plant could be increased. Based on the results, using humic acid due to improved phosphorus fertilizer use efficiency, phosphorous uptake by plant is expected to be increased and hence the fertilizer use would be reduced. Phosphorus influx results had not the same direction with uptake and application of phosphorus fertilizer. P influx results showed an inverse relationship with root length. In other words, phosphorus uptake was more dependent on the root growth.
Conclusion: This study showed that it is possible to use humic acid in the practical form during the cultivating of sugarcane setts, but it seems that further research is needed to examine other important points such as the use of humic acid during plant growth season and other its application forms, such as spraying or application in irrigation water.
Seyyedeh Zohreh Taghdisi heydarian; Reza Khorassani; Hojat Emami
Abstract
Introduction: The amount of soil nutrients and their availability for plants are the important aspects of soil fertility. Although micronutrients are used by plants in very small amounts, they play an active role in many plant-based processes and reactions influencing the plant growth and yield. The ...
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Introduction: The amount of soil nutrients and their availability for plants are the important aspects of soil fertility. Although micronutrients are used by plants in very small amounts, they play an active role in many plant-based processes and reactions influencing the plant growth and yield. The efficiency of absorption of micronutrient can be increased by adding some organic and mineral materials to soil. Saha et al. (41) observed an increase in micronutrient concentration of corn grain by adding organic materials to soil. Zeolite is one of the most commonly minerals used to increase agricultural production (17). The zeolites, due to their structure and porosity, are well-suited for retaining the nutrients and gradually releasing them into the root zone (40).Despite the positive effects of zeolite on some physical and chemical properties of soil, its application at high levels may adversely affect the absorption of nutrients and plant growth. Hamidpour et al. (18) who used zeolite for Zinnia flower, reported that zeolite reduced the yield of Zinnia flower. Basari et al. (4) reported that zeolite application increased soil pH and electrical conductivity (EC). Therefore, this research was carried out with the aim of assessing the influence of zeolite application, type (i.e. vermicompost and cow manure) and organic matter levels on the growth and the micronutrients uptake and determining the appropriate composition for corn.
Materials and Methods: A factorial experiment was conducted in a completely randomized design with three replications in greenhouse under controlled condition.The treatments consisted of raw zeolite (natural) in three levels (0, 6, 12% by weight), organic matter including vermicompost in three levels (0, 0.125, 0.25% or 0, 5, 10 t ha-1) and cow manure at three levels (0, 0.5, 1% by weight or 0, 20, 40 t ha-1).The soil was collected at a depth of 0-30 cm from the Mashhad Soil and Water Research Center. General soil characteristics and micronutrients concentration (iron, zinc and manganese) were determined according to standard methods (14, 27). For vermicompost and cow manure, some parameters such as pH and EC, organic carbon (46), available phosphorus and potassium (21), total nitrogen (7) and micronutrient (iron, zinc and manganese) were also measured (21). Further, pH, EC and micronutrient (iron, zinc, and manganese) were measured for natural zeolite (27). The pots were prepared by mixing 5 kg soil and experimental materials. N, P, and K were added according to soil testing. Irrigation with distilled water at field capacity level was done during the growth period. The plants were harvested75 days after sowing and after separating shoot and root, the plant materials were transferred to laboratory. Root and shoot dry weight were determined and after dry digesting of plant materials, the concentration of micronutrient were quantified by Atomic Absorption (21). The soil samples were also analyzed in order to determine the chemical properties of the soil after harvesting. Statistical analysis of the data was performed using JMP software and the mean comparison was carried out based on LSD test at 5% probability level.
Results and Discussion: The results of the experiment showed that increasing zeolite levels reduced dry weight, decreased height and uptake of zinc, iron and manganese and increased soil pH and iron and manganese concentrations. In addition, it was observed that the zeolite application had a negative effect on the plant growth and micronutrients uptake. Burriesci et al. (8) concluded that the zeolite application without fertilizing seems not to considerably increase plant growth. According to Kimberly and Nelson (24), the use of natural zeolite, without adding nutrients, leads to a competition between plant roots and zeolite for the nutrients absorption. Sarmetzidis et al. (42) showed that zeolite had no effect on the growth and yield of roses. Kolar et al. (25) reported that increasing the amount of zeolite in the geranium cultivar increased pH and the plants growth. At lower levels of zeolite, shoot fresh and dry weight was larger than that in higher levels of zeolite. Our results also denoted that the maximum amount of plant dry weight, plant height, the micronutrient (zinc, iron and manganese) uptake and the lowest soil pH were observed for the treatment of cow manure (1 %) in the absence of zeolite which had a significant difference relative to other treatments and also control. Shirani et al. (44) reported that the application of cow manure significantly increased corn dry matter. Ortiz and Alkaniz (36) showed that using organic fertilizers enhances the amount of absorbent metals such as iron, zinc and manganese as these metals are in a soluble and exchangeable form in these fertilizers. By releasing organic acids, the organic fertilizers, especially cow manure, reduce the localized pH of soil and increase the iron uptake by plants during the mineralization process.
Conclusion: According to the results, the use of zeolite increased soil pH, decreased corn growth and micronutrient uptake. Applying organic materials with zeolite can reduce the mentioned negative effect of zeolite. Cow manure at lowest level was more efficient than vermicompost at all levels. Overall, adding cow manure can improve the plant growth and micronutrient uptake by plant when the zeolite is intended to be used to modify soil physical characteristic.
majid forouhar; Reza Khorassani; Amir Fotovat; Hossein Shariatmadari; Kazem Khavazi
Abstract
Introduction: Global warming is strongly linked to the increase in greenhouse gas emissions to the atmosphere. One of the most efficient ways to reduce the amount of atmospheric CO2 is to produce a lot of biomass and convert the biomass into a biochar. Biochar is an organic carbon-rich solid that can ...
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Introduction: Global warming is strongly linked to the increase in greenhouse gas emissions to the atmosphere. One of the most efficient ways to reduce the amount of atmospheric CO2 is to produce a lot of biomass and convert the biomass into a biochar. Biochar is an organic carbon-rich solid that can be obtained from pyrolysis of various organic materials. In other words, biochar can be produced via thermal degradation of many organic materials such as vegetation biomass, animal waste, sewage sludge, etc. in absence or lack of oxygen. Biochar is more resistant to microbial degradation than its feedstock and has a mean resistance time of several decades. In connection with the use of biochar, the most researches have been done in non-fertile and highly weathered soils. The most significant effects of biochar application, have been also observed in strongly acidic soils. In many arid and semi-arid regions of the world, including Iran, the soil organic matter content is low. The lack of organic resources and their instability in the soil are considered as some of the most important challenges in improving soil fertility and plant growth and yield. To improve soil fertility by using insufficient existing organic resources, stabilizing organic matter by converting it into the biochar can be a fundamental strategy. If this strategy is applied in our country with calcareous soils, it is necessary to study the effects of different biochars on calcareous soils from different aspects .In this regard, in the present study, the effect of three types of biochar in a calcareous soil has been investigated in comparison with their feedstock.
Materials and Methods: The effects of three types of biochar and their feedstock in a calcareous soil were investigated in a 6-months period of incubation. A completely randomized design in the form of split plot experiment, was carried out. The main plots were consisted of Control, Municipal Waste Compost (MWC) and its biochar (BMWC), Sewage Sludge (SS) and its biochar (BSS) and Cow Manure (CM) and its biochar (BCW). The sub plots consisted of five sampling times as 10, 30, 60, 120 and 180 days after the beginning of incubation. Application rate of each treatment per kilogram of soil was calculated based on having the same weight of organic carbon content. So that all treatments contained 2.2 grams of organic carbon. After mixing the treatment with soil and adjusting the humidity to the moisture content of the field capacity (FC), they were transferred to the cans (with 3 holes embedded on their doors) and kept at 25°C in the incubator. During the 6-month incubation period, soil moisture was set at FC levels at intervals of two to three days. Sub samples were taken at five times. After air drying the sub samples, the chemical parameters such as EC of 1:2.5 extract, pH of 1:2.5 suspension, available phosphorus (extracted with sodium bicarbonate 0.5N) and available potassium (extracted with ammonium acetate 1N) were measured. After data collection, statistical analysis was performed using SAS software.
Results and Discussion: The soil texture was sandy loam with 21% of clay, 7% of silt and 72% of sand. Soil CaCO3 content and soil organic carbon content was 16% and 0.23% respectively. Available forms of potassium and phosphorous in soil were 76 and 6.3 mg kg-1, respectively. According to the results, under the influence of each treatment, the variation of soil available P, showed a significant increasing trend with the time. Changes in available potassium and soil pH were not significant over the time. Variation of soil salinity with time although showed an increasing trend but was not significant. Comparison of the effects of treatments showed that both biochars and their feedstock could significantly increase the available phosphorus and potassium in soil. In this regard, the effect of biochars was more pronounced than their feedstock. Among the feedstock, ranking for enhancing effect on available P, was SS > CM > MWC and among the biochars, it was BCM > BSS > BMWC. Ranking for enhancing effect on available K, was CM > MWC > SS and BCM > BMWC > BSS among the feedstock and biochars respectively. The increase in available phosphorus and potassium due to the use of biochars were much higher than that of total phosphorus and total potassium added by biochars. The soil pH decreased as a result of the application of each treatment compared to control. In this regard, the significant difference between biochars and their feedstock were not seen. Probable presence of some amounts of pyrogenic carbon with biochars can be one of the reasons for soil pH reduction. Electrical conductivity of 1:2.5 extract of soil was increased by all treatments compared to the control. Except for BSS, two other biochars significantly increased soil salinity more than their feedstock. This increasing effect on soil salinity can be partially due to the existence of some amount of ash accompanied with biochars.
Conclusions: Application of biochars derived from cow manure, sewage sludge or municipal waste compost in this experimental conditions, led to a significant increase in the amount of available phosphorus and potassium in soil compared to control and their feedstock. Therefore, the use of these biochars can have a high potential for reducing the consumption of some chemical fertilizers. From this point of view, the order of the superiority of the coal was as follows: biochar of cow manure > biochar of municipal waste compost> biochar of sewage sludge. The conversion of any of these feedstock to biochar did not have an effect on their potential for soil pH changes. Except for biochar of sewage sludge, in two other biochar, the potential for increasing soil salinity was higher than the feedstock. Considering that the durability of biochar in soil is much higher than that of its feedstock, it is possible to use suitable biochars such as those examined in this study as a great potential for the sustainable improvement of soil fertility and for reducing the use of chemical fertilizers in our country's agriculture. This requires extensive field researches for other soil properties in different soil and water conditions, with different kinds of biochars and crops.
faeze lotfi; amir fotovat; reza khorasani; Mahdi Bahraini
Abstract
Introduction: The pollution of soils by heavy metals due to human activities poses a serious concern for human and environmental health. In order to evaluate the risks of heavy metal contamination such as cadmium in soil, it is necessary to understand its bioavailability which depends on its chemical ...
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Introduction: The pollution of soils by heavy metals due to human activities poses a serious concern for human and environmental health. In order to evaluate the risks of heavy metal contamination such as cadmium in soil, it is necessary to understand its bioavailability which depends on its chemical forms in the soil. According to Tessier (1979), heavy metals can be found in various chemical forms in soil including exchangeable, bound to carbonates, bound to iron and manganese oxides and bound to organic matter and residual. These fractions significantly influence the cadmium mobility and bioavailability. Distribution of metals in chemical forms in soil depends on soil pH, amount of organic matter, oxidation-reduction potential and ionic strength. Root exudation, soil texture, cation exchangeable capacity and amount of calcium carbonate may also impact chemical forms of cadmium. Many studies have showed that plant root may affect the chemistry of heavy metals in soil root zone. The objective of this study was to evaluate the effect of organic matter on the distribution of cadmium in corn root media.
Materials and Methods: To investigate the effect of organic matter (cow manure) and root activity on chemical forms of cadmium, a greenhouse experiment was conducted using rhizobox. The contaminated soil sample used in the study was collected from Zanjan. This greenhouse experiment was conducted in a factorial design, with 2 replications, two levels of organic matter (0 and 1.5%) and three zones classified based on their distance from root. The soil samples were air dried and crushed to pass through a 2-mm sieve. The cultivation was conducted using a rhizobox. The rhizobox consisted of three parts: 1.central compartment (rhizosphere), 2.close to rhizosphere, and 3. soil bulk. Soil samples were mixed with fertilizer and packed in rhizobox. Eight pre-germinated maize seedlings were transferred to the central compartment and five days after germination, thinned to four plants. Ten weeks after planting, corn plants were harvested for analysis. The compartments of rhizobox were separated. The collected plant samples (root and shoot) were rinsed with deionized water and oven-dried at 70 °C. Soil samples were also measured for pH, CEC and total organic carbon. The chemical forms of cadmium in the soil and plant samples were identified by the sequential extraction procedure proposed by Tessier (1979). Bioavailable cadmium in soil was also extracted by DTPA-TEA.
Results and Discussion: Results showed that the highest amount of soil cadmium was found in carbonate fraction. Adding organic matter increased the soil pH, CEC and organic carbon amount, whereas none of chemical forms of cadmium were significantly affected by adding organic matter. Bioavailability of cadmium, however, decreased by adding organic matter to soil, It can be therefore concluded that increment in cadmium uptake due to increased organic matter led to decreased cadmium bioavailability. The exchangeable cadmium was negatively correlated to soil organic carbon, while bioavailable cadmium was negatively correlated to soil pH, CEC and amount of soil organic carbon. Moreover, our results indicated that the fractions of cadmium were not significantly affected by distance from the root. Moreover, adding organic matter insignificantly increased concentration of cadmium in shoots, roots and total plants.
Conclusion: In this study, among different chemical forms of cadmium, only bioavailable cadmium was significantly affected by adding organic matter to soil. Additionally, soil pH, CEC and organic carbon were significantly increased by adding organic matter. These results indicate that addition of organic matter to soil may indirectly influence chemical forms of cadmium through impacting soil properties (soil pH, CEC and organic carbon). The addition of organic matter had the most influence on carbonate fraction of cadmium which may be potentially available to plant. It seems that addition of organic matter (cow manure) may result in increase of cadmium concentration in plant. Therefore, it can be concluded that addition of cow manure to calcareous soils with neutral to slightly alkaline pH may lead to increased cadmium uptake by the plant (corn) and reduced soil cadmium concentration.
Saeed Bagherifam; A. Lakzian; A. Fotovat; R. Khorasani
Abstract
Introduction: Arsenic is a highly toxic metalloid in group 15 of periodic table. The information on environmental behaviour of arsenic, however, is still scarce. Contamination of soils and water with arsenic and antimony due to their widespread industrial application and mining activities has raised ...
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Introduction: Arsenic is a highly toxic metalloid in group 15 of periodic table. The information on environmental behaviour of arsenic, however, is still scarce. Contamination of soils and water with arsenic and antimony due to their widespread industrial application and mining activities has raised serious environmental concerns. Nearly all Arsenic-contaminated soils results from human activities and it has different environmental and sociological impacts. Various strategies and methods have been proposed for environmental management and remediation of contaminated soils. Among all methods, the phytoremediation is receiving more attention due to its cost effective and environmental friendly characteristics. In the case of arsenic contaminated soils, there are effective factors such as soil fertility, nutrients content and microorganisms function, which can improve the uptake of As by plants. Up to now, several studies have been evaluated the effects of symbiotic fungal association in plants on increasing nutrients and toxic elements uptake. Many of authors reported that the mycorrhizal symbiosis increases the uptake of toxic elements in root and shoot of plants and consequently improve the efficacy of phytostabilization and phytoextraction processes. There are conflicting results about the effect of arbuscular- mycorrhizal fungi (AMF) on As uptake by various plants. Chen et al. (4) found that Glomus mosseae symbiosis with plant reduces As concentration and enhance phosphorus content in shoot and root of plant. Whilst Cozzolino et al. (7) reported that the AMF increases as concentration in shoot and root of cabbage. Phosphorus has important role on mycorrhizal symbiosis and also As uptake by plants. Therefore, current study was conducted to evaluated effect of Glomus intraradices and Glomus mosseae symbiosis with sunflower and also soil phosphorus concentration on uptake of arsenic from arsenite and arsenate contaminated soils.
Materials and Methods:The soil sample (Typic Haplorthids) was collected, air dried and passed through 2 mm sieve and then were heated in 80 centigrade degree temperature for two times. A pot experiment was conducted in a completely randomized design with factorial arrangement and three replications in greenhouse condition. The experimental factors included two species spices of inorganic As (50 mg kg-1 of Arsenite and Arsenate), two levels of phosphorus (0 and 60 mg Kg-1) and three spices of arbuscular mycorrhizae (control, Glomus intraradices and Glomus mosseae). Soil samples spiked with Na2HAsO4.7H2O, NaAsO2 (Arsenite and Arsenate) and Ca (H2PO4)2 (phosphorus) and incubated in greenhouse condition for 4 week. Sunflower seeds were planted and seedlings harvested after 60 day of sowing and then dry weight of sunflower, concentration of As and phosphorus in shoot and root of plant and root colonization percentage determined using standard methods.
Results and Discussion:The results revealed that Glomus intraradices (GI) and Glomus mosseae (GM) symbiosis significantly (P
Mohammad Ghasemzadeh Ganjehie; Ali reza Karimi; Ali Zeinadini; Reza Khorasani
Abstract
Introduction: Playa is one of the most important landscapes in arid regions which covers about 1% of the world's total land area. Study of playas is important from different points of view especially pedology, sedimentology, mineralogy, environmental geology, groundwater and surface water chemistry. ...
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Introduction: Playa is one of the most important landscapes in arid regions which covers about 1% of the world's total land area. Study of playas is important from different points of view especially pedology, sedimentology, mineralogy, environmental geology, groundwater and surface water chemistry. More than 60 playas have been identified in Iran. Considering the fact that playas and surrounding landforms are important archive of landscape evolution and paleoenvironmental variations, it seems that less attention has been paid to them so far. Soils are known as indicators of the landscapes evolution. Previous studies in arid regions of Iran imply different periods of deposition and soil formation in playa and alluvial fans or pediments. Bajestan playa is one of the known playa in northeastern Iran, and the largest clay flat exists in this playa. There is no information on the soils and their evolution in Bajestan playa. The objective of this study were to 1) identify the soils in different landforms along a transect from alluvial fan to clay in Bajestan playa 2) determine the morphological, micromorphological and mineralogical characteristics of these soils 3) determine the periods of soil and landform evolution and 4) comparison of soils evolution of the study area to other arid regions of Iran.
Material and Methods: The study area of approximately 20000 hectares is located in southeastern of KhorasanRazavi province. The climate of the study area is hot and dry with mean annual temperature and rainfall of 17.3 °C and 193 mm, respectively. Soil moisture regime is aridic with subdivisions of weak aridic and soil temperature regime is thermic. Firstly, landforms and geomorphic surfaces of the study area were recognized based on Google Earth images interpretations and field observations. Four main landforms were recognized in the study area. The landforms from north to the south of the study area were alluvial fan, intermediate alluvial fan- clay flat, pediment and clay flat. Considering the diversity of geomorphic units, 11 soil profiles were described and diffrenet soil layers and horizons were sampled. Undisturbed soil samples were taken micromorphological studies. Some horizons were selected for clay mineralogy analysis. The mineralogy of clay fraction was determined using X-ray diffraction method.
Results and discution: All studied soils except the profiles in the pediment were classified in the Aridisols order. There were two geomorphic surfaces in alluvial fans. In the first geomorphic surface a soil with the Bk horizon buried a soil with red Btk horizon. In the second geomorphic surface, it seems that the erosion has been removed the overlying soil. The Bk horizon showed the maximum soil development in the clay flat and intermediate alluvial fan-clay flat landforms. Clay coating on sand in thin section was the evidence of clay illuviation in Btk horizon. Carbonate nodules associated with clay coating are the compound pedofeature in Btk horizon. These evidences reflect polygenetic nature of the soils and different period of climate change and soil formation. Smectite, mica, chlorite and palygorskite are the clay minerals in the studied soils. Similar to soils in arid regions of Iran, palygorskite was found in Bk, Bt and Bz horizons. The existence of Bk horizon in overlying soils, buried Btk horizon, removal of surface horizon in alluvial fan are the evidences of regressive and progressive of pedogenic processes in the study area. Btk horizon represents a warm and wetter and Bk horizon indicates a relatively wetter period in comparison to present time.
Conclusion: Btk was the most developed horizon in the study area that occurred as buried paleosol in alluvial fan. Bk, Bw, By and Bz were the common horizon in other landforms. Clay coating and red color of Btk horizon might seem as indicators of hot and humid conditions in the past, during the argillic horizon formation. Covered carbonate nodules with clay coating can also be mentioned as sign of a hot and wet period which is suitable for clay illuviation and weathering after a period of carbonate accumulation. The buried Btk horizon under alluvial layers in the alluvial fan indicates that after apedogenic period, alluvial processes have been responsible in burying this horizon. Bk horizon in overlying soil of all landforms represents a less intense period of soil formation. The dominant clay minerals in the study area were Illiite, cholorite, kaolinite, and palygorskite. The sequence of Bk and Btk horizons in this research and the occurrence of these soils in central, eastern and northeastern Iran imply the similar pedogenetic conditions in arid regions of Iran.
amir ranjbar; H. Emami; Ali reza Karimi; R. Khorassani
Abstract
Introduction: Saffron is one of the most important economic plants in the Khorasan province. Awareness of soil quality in agricultural lands is essential for the best management of lands and for obtaining maximum economic benefit. In general, plant growth is a function of environmental factors especially ...
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Introduction: Saffron is one of the most important economic plants in the Khorasan province. Awareness of soil quality in agricultural lands is essential for the best management of lands and for obtaining maximum economic benefit. In general, plant growth is a function of environmental factors especially chemical and physical properties of soil (20). It has been demonstrated that there was a positive and high correlation between soil organic matter and saffron yield. Increasing the yield of saffron due to organic matter is probably due to soil nutrient, especially phosphorous and nitrogen and also improvement of soil physical quality (6, 28, 29). The yield of saffron in soils with high nitrogen as a result of vegetative growth is high (8). Shahandeh (6) found that most of the variation of saffron yield depends on soil properties. Due to the economic importance of saffron and the role of soil properties on saffron yield, this research was conducted to find the relationship between saffron yield and some soil physical and chemical properties, and to determine the contribution of soil properties that have the greatest impact on saffron yield in the Ghayenat area.
Materials and Methods: This research was performed in 30 saffron fields (30 soil samples) of the Ghayenat area (longitude 59° 10΄ 10.37˝ - 59° 11΄ 38.41˝ and latitude 33° 43΄ 35.08˝ - 33΄ 44΄ 02.78˝), which is located in the Khrasan province of Iran. In this research, 21 soil properties were regarded as the total data set (TDS). Then the principal component analysis (PCA) was used to determine the most important soil properties affecting saffron yield as a minimum data set (MDS) and the stepwise regression to estimate saffron yield. To estimate the yield of saffron in stepwise regression method, saffron yield was considered as a dependent variable and soil physical and chemical properties were considered to be independent variables.
Results and Discussion: According to the PCA method, among the 21 studied properties, 7 out of them including calcium, iron, zinc contents, sand, calcium carbonate equivalent percent, mean weight diameter of aggregates (MWD) and manganese (Mn) had the higher Eigenvalues. Therefore, the above properties were introduced as the most important soil properties in saffron fields. Calcium carbonate had the negative effect on the availability of micro-nutrients (26). Christensen et al. (15) found that by increasing the calcium carbonate in soil due to high pH and formation of insoluble components, the uptake of micro-nutrients is especially limited.
The results of stepwise regression method (equation 1) showed that soil acidity (pH), zinc content, bulk density, MWD, iron content, salinity (EC), organic carbon and available potassium in soil were the most important properties that affect the yield of saffron, so that the determination coefficient (R2) of the regression model was high (Table 2) and it can explain 74% of the variation of saffron yield.
Y = 6924.51 – 1187.31 pH – 89.65 EC + 71.6 Fe – 826.02 Zn + 471.55 OC, + 5490.96 K + 1353.56 BD + 752.82 MWD (1)
where Y: saffron yield (kgha-1), pH: soil acidity, EC: electoral conductivity (dSm-1), Fe: iron concentration (mgkg-1), Zn: zinc concentration (mgkg-1), OC: organic carbon (%), K: soil potassium (%), BD: soil bulk density (Mgm-3), and MWD: mean weight diameter of aggregates (MM).
Based on the absolute values of standard ß in the regression model (Table 3), pH value and then after Zn concentration had the most effect on saffron yield. In general, responses of different plants to soil pH is varied, and saffron grows satisfactory in pH = 7.8 (5). Soil pH influences the uptake of soil nutrients by plants (15), so that this parameter had the most effect on saffron yield and by increasing the soil pH, the yield of saffron decreases. According to the regression model, Zn concentration was the second parameter in saffron yield. Zn has the important role in structure of plant enzymes (30). After these 2 parameters, Bd, MWD, Fe concentration, EC, Organic carbon and K concentration in soil had more effect on saffron yield (Table 3).
Conclusion: According to both PCA and regression methods, the concentration of iron and zinc and MWD were determined as the important and effective soil properties on saffron yield in the Ghayenat area. In addition, soil pH in stepwise regression method and calcium carbonate in PCA method were determined as the effective properties on saffron yield. Therefore, it is suggested that the parameters of Zn, Fe, and MWD along with soil pH and calcium carbonate which were regarded individually in two methods, were considered as the most soil properties in saffron yield.
salimeh rahemi; R. Khorassani; A. Halajnia
Abstract
With due attention to the low availability of iron in calcareous soils and different ability of plant species in iron acquisition, the study and identification of iron-efficient plants is necessary to reduce the use of chemical fertilizers. In this way, a greenhouse experiment was conducted to study ...
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With due attention to the low availability of iron in calcareous soils and different ability of plant species in iron acquisition, the study and identification of iron-efficient plants is necessary to reduce the use of chemical fertilizers. In this way, a greenhouse experiment was conducted to study of iron uptake efficiency in different wheat varieties, as a randomized complete blocks design with factorial arrangement. Treatments consisted of three levels of Fe (0, 2 and 6 mg kg-1) and three varieties of wheat (Falat ٫Parsi ٫Pishtaz) with three replications. The results showed that iron application had no effect on shoot dry weight and iron uptake in Parsi and Pishtaz varieties, but increased those in the Falat variety. The study of influx and root-shoot ratio, which are two important factors in the iron uptake by plant, showed that the Parsi and Pishtaz varieties had higher influx than the Falat variety. In the Parsi variety as well as influx, the root length had an important role in iron uptake efficiency. In the Falat variety with increasing amounts of iron uptake, relative shoot dry weight, influx and root-shoot ratio were increased. Therefore, the Falat variety in comparison to two other varieties was not an iron efficient plant. Lack of response to Fe fertilizer in the Pishtaz and Parsi varieties indicated some other specific uptake mechanisms were involved at low Fe levels in soil. Finally, the results showed that the Pishtaz and Parsi varieties were more efficient in iron uptake than Falat variety.
T. Javaheri; A. Lakzian; P. Taheri; R. Khorasani
Abstract
Organic phosphorus is the dominant part of soil phosphorus. Phytic acid and sodium Glycerophosphate are two different forms of soil organic phosphorus. Soil fungi play an important role in the conversion of these compounds into inorganic forms. Among the fungi, Aspergillus is one of the most effective ...
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Organic phosphorus is the dominant part of soil phosphorus. Phytic acid and sodium Glycerophosphate are two different forms of soil organic phosphorus. Soil fungi play an important role in the conversion of these compounds into inorganic forms. Among the fungi, Aspergillus is one of the most effective organisms in hydrolysis of organic compounds. In order to study the ability of Aspergillus fungi on the hydrolysis of Phytic acid and sodium Glycerophosphate, an experiment was conducted as a completely randomized design with factorial arrangement and three replications. The first experimental factor include five fungi isolates (four Aspergillus isolates, Trichoderma harzianum and control) and the second factor include two different organic phosphorus compounds (Phytic acid and Sodium Glycerophosphate). All isolated were grown in PDB at 28 oC and rate of hydrolysis of inorganic phosphorus was determined after 14 days inoculation. In addition, acid and alkaline phosphatase activity and medium pH were measured. The results showed that Aspergillus isolates and Trichoderma harzianum mineralized organic phosphorus significantly (p
R. Khorassani; M. Azizi; H. Rahmani
Abstract
Most of medicinal plants are able to grow in low P supply as well. In order to study the ability of some medicinal plant species, a greenhouse experiment was conducted with Salvia virgata, Achillea millefolium and Ziziphora clinopodioides Lam in a low P soil. The experiment was undertaken with three ...
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Most of medicinal plants are able to grow in low P supply as well. In order to study the ability of some medicinal plant species, a greenhouse experiment was conducted with Salvia virgata, Achillea millefolium and Ziziphora clinopodioides Lam in a low P soil. The experiment was undertaken with three levels of P (0, 15, 150 mg kg-1), two harvests and three replications as a randomized complete block design. In the second harvest and low P treatment, all species showed a high relative shoot dry matter (above 80%) which indicated a high P use efficiency of them. The range of shoot P concentration in low P treatment at the first harvest was between 0.23% and 0.29%. In this case, no significant difference was observed among different P treatments. In addition, the shoot P content of plants was almost high. As a result, all three plant species were P uptake efficient plants. The P influx in Ziziphora clinopodioides Lam was more than two other plant species. The results of the root- shoot ratio of plants at low P supplied was indicated that high P uptake efficiency of Salvia virgata was mostly due to its extensive root system, whilst, for Ziziphora clinopodioides Lam it was mostly due to its high P influx.
L. Ghorashi; Gh. Haghnia; A. Lakzian; R. Khorasani
Abstract
Iron is an essential micronutrient for plant growth. The existence of lime, low content of organic matter and excess application of phosphate fertilizer in soils are the factors affecting its availability. In this study the effects of lime, phosphorus and organic matter on growth and iron uptake of maize ...
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Iron is an essential micronutrient for plant growth. The existence of lime, low content of organic matter and excess application of phosphate fertilizer in soils are the factors affecting its availability. In this study the effects of lime, phosphorus and organic matter on growth and iron uptake of maize were evaluated. A greenhouse experiment was conducted with two levels of lime (0, 2% calcium carbonate) two levels of organic matter (0 , 1% cattle manure),three levels of phosphorus (0, 200, 400 kg ha-1 triple super phosphate). The experimental design used, was completely randomized ,factorial, with 2 replications. Results showed that application of cattle manure significantly increased shoot dry weight, iron concentration and iron uptake of maize. The application of lime had no significant effect on shoot dry weight however it decreased iron concentration and iron uptake of maize. Application of phosphorus increased shoot dry weight but decreased iron concentration and iron uptake of plant. The study of organic matter interaction with one of the other treatments showed that application of organic manure can improve the negative effects of lime and phosphorus.
A. Maadani; A. Lakzian; Gh. Haghnia; R. Khorasani
Abstract
High concentration, of heavy metals and the presence of phosphorus in soils may cause a reduction in the growth and activity of arbuscular mycorrhizal (AM) fungi and consequently, the spore production of these fungi would decrease. In order to evaluate the effect of zinc and cadmium as heavy metals and ...
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High concentration, of heavy metals and the presence of phosphorus in soils may cause a reduction in the growth and activity of arbuscular mycorrhizal (AM) fungi and consequently, the spore production of these fungi would decrease. In order to evaluate the effect of zinc and cadmium as heavy metals and phosphorus on arbuscular mycorrhizal fungi activity through measuring glomalin produced by these fungi a factorial experiment arranged as completely randomized design was carried out. Experimental factors included two fungal species G. mosseae and G. intraradices and non mycorrhiza (NM), six combinations of metals (400 mg of Zn, 25 mg of Cd, 400 mg of Zn + 25 mg of Cd, 50 mg P, 50 mg of P+ 400 mg of Zn + 25 mg of Cd, and no metal kg-1 soil sample) in three replications. The results showed that inoculated treatments produced more glomalin compared to non mycorrhizal treatments. The application of Cd, Zn and P caused a significant reduction in produced glomalin by both fungi species. The most reduction of glomalin in G. intraradices was detected in Cd treatment and in G. mosseae was in Zn treatment. The result also showed a positive correlation between the measured glomalin by Bradford assay and the percent of root colonization. According to the results of this study, glomalin in soil could be an indicator to monitor arbuscular mycorrhizal fungi activity and soil health.
Sh. Shafaei; A. Fotovat; R. Khorasani
Abstract
Iron (in zero-valent and oxide forms) is used to remove numerous organic and inorganic contaminants in environment. However, there are few reports, especially in nano scale, on the remediation of heavy metals contaminated soils using zero-valent iron in the literature. In this study, the effect of iron ...
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Iron (in zero-valent and oxide forms) is used to remove numerous organic and inorganic contaminants in environment. However, there are few reports, especially in nano scale, on the remediation of heavy metals contaminated soils using zero-valent iron in the literature. In this study, the effect of iron on the availability of heavy metals was evaluated in a calcareous soil spiked with cadmium, zinc, lead and nickel. The soil samples, in a randomized complete design with two replications, were amended with four iron materials including micrometric zero-valent iron (ZVI), nanoscale zero-valent iron (nZVI) and nano and micro scales iron oxides. Then, after 1, 2 and 4 weeks of the experiment, DTPA-extractable heavy metals in soil were determined. Results showed that DTPA extractable heavy metals significantly decreased in soil treated with zero-valent iron, compared to untreated soil The stabilization efficiency of Ni, Cd, Zn and Pb was 28%, 32%, 37% and 28% for ZVI and 12%, 0%, 25% and 21% for nZVI, respectively. In contrast, presence of iron oxides caused significant increase of DTPA extractable heavy metals in soil except for Ni. Moreover, Ni-DTPA decreased significantly with time whereas it was constant for the other elements examined. In this study, the observed capacity for heavy metals removal by ZVI was higher than other treatments whereas the stabilization efficiency of nZVI was not significant in the soil.
A. Aama Azghadi; R. Khorassani; M. Mokarram; A. Moezi
Abstract
Abstract
Nowadays, fuzzy technique is used to prepare the map in different sciences, extensively. With due attention to important role of soil fertility in modern agriculture, the preparation of soil fertility map seems to be necessary to plan for appropriate using of fertilizers for crops. This study ...
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Abstract
Nowadays, fuzzy technique is used to prepare the map in different sciences, extensively. With due attention to important role of soil fertility 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 available K and P, and soil organic matter factors in Shavor region in Khuzestan province. The fuzzy technique and the Analytic Hierarchy Process (AHP) were used for mapping soil fertility into Geographic Information System (GIS). For this, the amount of soil organic matter, and available soil phosphorus and potassium obtained form 282 profiles of soil, as the input data, were used. In the first stage the interpolation of data was done by Inverse Distance Weighting (IDW) model into GIS. Then a membership functions was defined for each factor. Finally, the map of soil fertility was prepared by using AHP technique into program of Expert Choice with adjustment rate of 0.05. Results showed that 51, 26, 12 and 11 percentage of lands were classified base on soil fertility into groups of very weak, weak, moderate and suitable, respectively. As a final result, this types of distinct soil fertility map can able us to manage the appropriate using of fertilizer.
Keywords: Geography Information System (GIS), Fuzzy logic, Analytic Hierarchy Process (AHP), Soil fertilize
R. Khorassani
Abstract
Abstract
Plant species differ in their ability to grow at low available P soils in other words, plant species differ in P use efficiency at low P supply. This ability can be investigated by comparing P uptake efficiency of plants and relative effective factors. A pot experiment was carried out in the ...
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Abstract
Plant species differ in their ability to grow at low available P soils in other words, plant species differ in P use efficiency at low P supply. This ability can be investigated by comparing P uptake efficiency of plants and relative effective factors. A pot experiment was carried out in the growth chamber and sugar beet, maize and groundnut were grown in a low available P soil in a completely randomized design with three P fertilizer levels of low, medium and high. Three harvests were performed at two different growth periods. The results showed that at low P supply, sugar beet was the most efficient plant among three species as it showed the highest relative yield. The higher P use efficiency of sugar beet was due to a higher P uptake efficiency. Phosphorus uptake for sugar beet was 29 mg P plant-1 while those for maize and groundnut were 19 and 0.8 mg P plant-1, respectively. The main reason for higher P uptake efficiency of sugar beet was its higher P influx as compared to maize and groundnut. Under low P supply during the first growing period, P influx of sugar beet was higher than that of maize and groundnut by factor 4 and 22, respectively. Finally, the higher P use efficiency of sugar beet was due to a higher P uptake efficiency which in turn was due to a high P influx.
Keywords: Phosphorus efficiency, Phosphorus influx, Sugar beet, Corn, Groundnut