علیرضا مرجوی

Evaluating the spatial variability of soil properties is an important prerequisite for precision agriculture. This research was conducted on 84 soil samples from different areas of Chadegan city (Isfahan province). With the aim of evaluating the spatial variability of some soil nutrient elements, including organic carbon, soil-available phosphorus, potassium, zinc, copper, manganese, and iron. The spatial correlation of each variable with a specific semi-variable and the best fitting model for each variable were selected. Interpolation was done using normal Kriging and Inverse Distance Weighting with powers of 1 to 3 methods. The accuracy of the distribution maps of these variables was evaluated by the Mean bias error (MBE) the standard root mean square error (NRMSE), and the coefficient of determination (R2). The results showed that all studied properties had moderate spatial dependence, which shows the effect of management factors such as fertilization, plowing, irrigation, etc. on these variables. The exponential model was the most accurate to predict organic carbon, phosphorus, potassium and zink variables while iron, copper, and manganese were best fitted with an spherical model. For phosphorus, iron, and copper variables, the Inverse Distance Weighting with the power of 1 (IDW-1) and for organic carbon, potassium, zinc, and manganese normal kriging methods were recognized as the best interpolation methods. According to the spatial distribution maps, the studied area is sufficient in terms of potassium, copper and manganese nutrients, and in other cases, the use of fertilizers and organic materials is necessary to increase soil fertility.

Knowing about the spatial dependence of different soil characteristics in farms is important to achieve more production and better management. The aim of this study was to evaluate the spatial variability and frequency distribution of some physical and chemical properties, including pH, EC, organic carbon, phosphorus and potassium that can be used by plants, texture and cation exchangble capacity, within the various landforms of Isfahan province. The study was conducted on 118 soil samples. The spatial correlation of each variable with a specific semi-variable and the best fitting model for each variable were selected using GS+ version 9 software. Interpolation was done using normal Kriging, Cokriging, and Inverse Distance Weighting with powers of 1 to 3. The accuracy of the distribution maps of these variables were evaluated by the mean deviation of error (MBE) and the root mean square error (RMSE). The results of the geostatistical analysis showed that potassium, sand percentage and pH had strong spatial dependent and the other characteristics had moderate spatial dependent. The exponential model was the most accurate to predict phosphorus, EC, CEC, clay and silt variables while potassium, pH, sand and organic carbon percentage were best fitted with an sphericalmodel. Also, EC had the smallest effective range (14.86 km) and pH had the largest effective range (around 71 km). For potassium, pH and EC variables, the Inverse Distance Weighting with the power of 1 (IDW-1) and for other variables the normal kriging method were recognized as the best interpolation methods.

To study the effect of different amounts of municipal compost and sewage sludge on soil properties and wheat, a field experiment was conducted in Ruddasht research station in Isfahan, for five years. Five treatments including 25 and 50 t/ha/year of municipal solid waste compost and 15 and 30 t/ha/year of sewage sludge and control treatment (non-application of organic fertilizer) were used in a randomized complete block design with three replications for five years. The organic fertilizer application increased organic matter in the soil. Also, the application of organic fertilizers, especially at higher levels, increased phosphorus, potassium, iron, copper, manganese, zinc, cadmium and lead in the soil. Also, the application of organic fertilizers increased signifivantly phosphorus, potassium, nitrogen, iron, copper and zinc in the grain and straw of wheat. The concentration of these elements increased significantly with application of organic fertilizers after five years. For manganese, this trend was reversed due to the antagonistic relationship with the iron element. The concentration of lead and cadmium in the plant was so low that it could not be measured by atomic absorption. In general, municipal waste compost and sewage sludge increased the soil organic matter and the concentration of nutrients in the plant, especially in terms of micronutrients such as zinc and iron.

This study was conducted to evaluate the effect of saline irrigation on yield and yield components of cotton genotypes. Experiments were carried out at Rudasht saline Research Station in Isfahan during 2013, 2014 and 2015. In the first year, two cotton mutant genotypes and two commercial cultivars as control were selected for the second and third years. The second year experiment was split factorial based on randomized complete block design with four replications. In this experiment, the main plots consisted of irrigation with 4 (control), 8 and 12 dS / m saline water and subplots including factorial combining of three genotypes (mutant genotype 1673, LM 1303 and Shayan) with spraying three levels of potassium sulfate (2, 4 and 6 kg / 1000 liters of water per hectare and water). The results showed that salinity of irrigated water reduced linter percentage, yield and harvest index. Among the cultivars, the highest linter percentage and its yield were observed in the LM 1303 genotype. Spraying with potassium sulfate had a positive effect on these traits and increased cotton genotypes yield under salinity conditions. The results of this study showed that in saline conditions, soluble potassium sulfate was used to reduce the effects of salinity and increase the yield of cotton genotypes. Also, the results of this study showed that the LM 1303 mutant genotype during the two years of experiment had a higher yield compared to other genotypes, and this genotype could be recommended for planting in saline areas

Degradation of water, soil and environmental resources by the excessive use of chemical materials encour aged researchers to focus on organic farming in recent years. Despite all positive effects associated with the consumption of municipal compost and sewage sludge on the physical and chemical properties of the soil, there are still many concerns about their environmental and health issues. The aim of this study was to investigate the heavy metal accumulation in the soil and plant using different amounts of municipal compost and sewage sludge in a field trial after five years.

The field study was conducted in Rudasht Irrigation and Drainage Research Station, Isfahan, Iran. A randomized complete block design with three replications within treatments was employed. The crop rotations were onion, wheat, sugar beet, corn, and onion, so there were two stages of onion cultivation. The treatments were 0 (as control), 25 ton ha-1 municipal compost, 50 ton ha-1 municipal compost, 15 ton ha-1 sewage sludge and 30 ton ha-1 sewage sludge applied per planting during five years.

Application of municipal compost and sewage sludge, especially at higher levels, increased the soil organic matter twice. In addition, the concentration of phosphorus (P), potassium (K), iron (Fe), copper (Cu), manganese (Mn), zinc (Zn), and lead (Pb) in the soil increased significantly. Concentrations of available lead (Pb) and cadmium (Cd) in the first onion planting stage in the soil were not significant, but in the second onion planting stage the lead (Pb) concentration in 50 ton ha-1 municipal compost increased significantly (from 1.9 mg kg-1 in control treatment to 5.62 mg kg-1 in 50 ton ha-1 municipal compost treatment). Application of organic fertilizers increased the essential elements (e.g., N, P, K, Zn, Mn, and Cu) in onion shoot. The highest amounts of nutrient elements in onion shoot were detected in 50 ton ha-1 municipal compost,
which was not significantly different than 30 ton ha-1 sewage sludge. In the first stage, the absorption of copper (Cu) by plant shoot was lower than the second stage as a result of increasing concentration of other elements such as phosphorus (P) and competition between various elements. The highest copper (Cu) concentration in shoots was observed in 15 ton ha-1 sludge (5.4 mg kg-1), which reached to 3.76 mg kg-1 after five years in the second stage. Application of organic fertilizers at both stages increased zinc (Zn) concentration in the onion bulb. The highest zinc (Zn) concentrations in bulbs were measured in 50 ton ha-1 compost and 30 ton ha-1 sewage sludge treatments (3.05 and 3.87 mg kg-1 for the first stage and 4.25 and 4.50 mg kg-1 for the second stage, respectively). However, the concentrations of other nutrients such as N, K, Cu and Fe in the onion bulb increased at the second stage. The highest concentrations of N (0.18%) and Fe (0.81 mg kg-1) in the bulb were measured in 50 ton ha-1 compost and the highest concentration of Cu (0.52 mg kg-1) was in 30 ton ha-1 sludge. The concentrations of lead (Pb) and cadmium (Cd) in the plant were undetectable by atomic absorption in different treatments.

Long-term consumption of municipal compost and sewage sludge increased the soil organic matter and im proved the physical and chemical properties of the soil. Furthermore, these organic resources increased the concentration of nutrient elements, especially micronutrients including zinc (Zn) and iron (Fe), in the plant. One of the main concerns about such organic resources is the possibility of soil and plant contamination by heavy metals. The results of this study showed that the multi-year consumption of these materials did not increase the heavy metal elements such as lead (Pb) and cadmium (Cd) in the soil or plant. Considering the low amount of organic matters in the soil of most parts of the country and the limited availability of various organic resources, using such organic matters in agriculture would be one of the best methods for recycling these materials and would be very important to have sustainable agriculture.

To study the effect of different amounts of municipal compost and sewage sludge on soil properties and yield of maize after one and five years of consumption, a scientific experiment was conducted in Rudasht irrigation and drainage research station of Isfahan, Iran. The applied treatments of 25 and 50 t/ha of municipal compost and 15 and 30 t/ha of sewage sludge and control treatment (non-application of organic fertilizer) before planting, were used in constant plots in a randomized complete block design with three replications. As a result of organic fertilizer consumption, the pH decreases and concentrations of some essential elements concordant with the lead element increased significantly in the soil. The amounts of micro and macro elements were also increased in harvested corns. It was clear that the concentrations of those elements have increased in soil and corn after five years compared with one year of organic fertilizer consumption. The yield of corn was increased significantly by five year of fertilizer usage in comparison with control treatment

A novel method of monitoring soil pollution by heavy metals is using magnetometry as a cost-effective, simple, efficient, and fast method. In the present study, the potential of the magnetometric method to monitor the plant nutrient elements such as iron, manganese, zinc, and copper in the bioavailable fraction was evaluated. Also, their relationship with the greenhouse soil physicochemical characteristics of two towns of Isfahan Province (Dehaqan and Shahreza) were investigated. A total of 40 topsoil samples were collected (0-20 cm depth) from the study area in summer 2014 and the magnetic susceptibility (χ) of the collected samples was measured at both low and high frequencies (χlf and χhf) using the Bartington MS2 dual frequency sensor. The results indicated that there were no significant correlations between the soil magnetic susceptibility and the bioavailable forms of Cu, Zn, and Mn in the whole of the study area. This could be probably due to lack of penetration of these elements into the lattice structure of the ferromagnetic materials. The negative correlations between magnetic susceptibility and Fe showed that the increase of the bioavailable concentration of Fe is not necessity related to its high contents in the soil magnetic structure, so, it would not affect magnetic susceptibility positively. In addition, there was positive significant correlation between the magnetic susceptibility and clay and silt content as well as a negative significant correlation with sand content. Also, the low values of soil magnetic susceptibility in the bioavailable fraction (30.30 15±"> 7.89 15×"> 10-8 m3 kg-1) reflects the dominant effect of the bedrock and the inherent characteristics of soil on metals concentrations in the region. Based on this study, it can be concluded that in order to monitor the heavy metals in the bioavailable fraction of soils, and also in areas that are not affected by certain sources of pollution, monitoring techniques based on magnetic susceptibility do not have high efficiency.

The study was conducted during 2002- 2007 in the first and last stage of a four-year rotation (sugar beet, forage maize, onion, wheat and sugar beet) at Research Station of Irrigation and Drainage Rudasht. In each year, four treatments of organic fertilizers (25 and 50 t/ha urban compost and 15 and 30 t/ha sewage sludge) with a control (no organic fertilizer) were studied in a randomized complete block design with three replications. It was revealed that the maximum organic carbon content, available potassium and lead in the soil was observed in the 50 t/ha urban compost, treatment whereas the maximum available phosphorous and copper in the soil was associated with the application of 30 t/ha sewage sludge. As time elapsed, the available zinc in the soil was enhanced significantly by application of urban compost. Utilization of urban compost as well as sewage sludge significantly enhanced the sugar beet root yield. However, the sugar content was decreased. The decrease in sugar content was greater for the sewage sludge treatment than for the urban compost treatment. In the last year of the rotation, the effect of application of the organic fertilizer on sugar yield was not significant. However, due to the increase in the root impurities resulted from the application of urban compost as well as sewage sludge, the white sugar yield in the last year showed a significant decrease in comparison with that of the first year of the rotation. It follows that continuous application of the types of organic fertilizers, particularly the sewage sludge, to the Rudasht district of Esfahan as well as regions with a fine textured soil is not recommended.

In order to evaluate salinity tolerance of six bread wheat varieties, an experiment was conducted during 2000-02 crop seasons in Roudasht Salinity Research Station, Esfahan. Effects of three levels of irrigation water salinities (four, eight and 12 dS m-1) were studied on six bread wheat cultivars including Pishtaz, Shiraz, Mahdavi, Marvdasht, Kavir and Roshan. Increase in salinity level of irrigation water caused significant decrease in grain yield, number of spikes per m2, days to physiological maturity, plant height and grain filling period. Among the varieties, Roshan and Shiraz had the minimum reduction percentage in grain yield in 12 dS m-1 compared to 4 dS m-1. In 12 dS m-1, Roshan and Shiraz produced 3987 and 3607 kg ha-1 grain yield, respectively and had the highest grain yield values among the varieties. Roshan also had the highest amounts of MP, GMP and STI (4257, 4248 and 1.20, respectively) and the lowest amounts of Tol and SSI (539 and 0.66, respectively), thus was the most tolerant cultivar to salinity among the studied cultivars. Based on the tolerance and susceptibility indices, Marvdasht was the most susceptible cultivar to salinity.

They are few reports on the effect of municiple compost on the soil properties, quality and quantity of sugarbeet. The aim of this study was to obtain information about municipile compost on the soil properties, quality & quantity of of sugarbeet.A field study was conducted at Baraan Rsearch Station with sugarbeet-wheat rotation in permanent plots. The experimental design was factorial combination with 0, 25 & 50 ton/ha municiple compost and 0, 60 & 120 kg/ha nitrogen at four replication. Compost chemical analysis showed that the lead level was higher than the permissible level. The effect of municiple compost was significant on P, K, Fe, Zn, Cu & Pb in soil. At the second years the effect of nitrogen wasn’t significant on root and sugar yield, because of high N-NO3 in irrigation water. Application of municiple compost is not recommended befor planting of sugarbeet, because of increase soil nitrate content decrease of sugar yield.