Journal of Soil Management and Sustainable Production
Year:2018 | Volume:8 | Issue:3 |Papers Count:9

Background and Objectives: Supply of micronutrients is necessary for the improvement of plant biological processes. The total amount of elements in soil is not an appropriate indicator for plant availability, because main portion of nutrients are usually as unavailable forms. Humic substances can change the chemical forms of elements in soil. Therefore, this study was done to investigate the influence of humic substance on changes of chemical forms of manganese (Mn) in some cultivated soils of Urmia region. Materials and Methods: Twenty soil samples were collected of 0-30 cm from the fields of Urmia region. Some physicochemical properties of soils were measured by standard methods. DTPA extractable Mn and clay mineralogy of soils were also determined. FT-IR spectra were analyzed to determine the functional groups of leonardite. Laboratory evaluations were carried out as a factorial in a completely randomized design with three replications. Four different soil samples were selected and were treated by 200 mg kg-1 MnSO4. H2O and were incubated for two months at field capacity moisture. Different levels of leonardite (0, 2 and 4%) were added after incubation. Laboratory evaluations were carried out as a factorial in a completely randomized design with three replications. The concentration and chemical forms of the Mn were evaluated using DTPA and sequential extraction Tessier method respectively after 20, 60 and 120 days. Results: The results showed that the quality and quantity of the clay minerals were different and the illite mineral was dominant in the studied soils. Results showed that the leonardite have different functional groups and showed significant effect on increasing plant available Mn (P<0. 001). Also, leonardite application increased the amount of Mn extractable with DTPA solution. The results showed that more than 76-85% of Mn (exchangeable, carbonate-, Fe-Mn oxides-, organic matter-bonded) was extracted in a sequences extraction method. In addition, a large part of Mn was absorbed in the oxide form (more than 50%) and lowest value in the exchange form (less than 0. 1%). Effect of leonardite on increasing Mn availability was decreased as a calcium carbonate increased in soil. As, the highest Mn available (4. 5 ppm) obtained in the Ordushahi soil with the least amount of calcium carbonate was observed. Analysis variance showed that the main effects of soil, leonardite and their interactions were significant in changing chemical forms of Mn (P<0. 001). The exchangeable, carbonate and organic carbon forms of Mn increased significantly (0. 01) as leonardite treatment. As well as a significant decrease (4. 5-11. 6%) in the section related to Fe-Mn oxides were observed. Conclusion: The results showed that the leonardite can to changes the chemical forms of elements to improve adsorption of nutrient for plants. In addition, a positive significant correlation was observed between the amount of Mn extractable with DTPA solution and chemical forms of Mn. The effect of contact time was significant on Mn availability and extracted of high Mnwith increasing the incubation time. The effect of 4% Leonardite treatment was more than 2%. Accordingly, the use of leonardite is suitable to increase of productivity and supply micronutrients and can be used as biodegradable materials in improving the quality and quantity of agricultural products.

Background and Objectives: Bean (Phaseolus vulgaris L. ) is one of the Biological Nitrogen Fixation (BNF) in pulse crops. The simple and interaction effects between microorganisms, especially fungi, phosphate and Zinc (Zn) solubilizing microorganisms and Rhizobium bacteria can have very effective impacts on nutrient uptake, plant height, branch number, germination, plant growth, nodulation, BNF, colonization and yield in different plants. This study was done to evaluate the effect of Phosphate, Nitrogen (N) and Zn bio-fertilizers on growth morphological characteristics, nodulation, BNF and root colonization in two cultivars of bean. Materials and Methods: This experiment was carried out as a factorial in a randomized complete design (RCD) with three replications. The research treatments consisted of two cultivars of Pinto bean (Talash and Sadri), four levels of Phosphurus (P) (P0: Control, P1: Use of triple super phosphate (TSP) fertilizer on the basis of soil test, P2: 50 percentage of TSP recommendation and phosphate bio-fertilizer that consist of of inoculum of Funneliformiss mosseae, Rhizophagus intraradices and Clariodeoglomus etunicatum with Azotobacter bacteria and P3: Use of P bio-fertilizer), three levels of N (N0: Control, N1: Use of urea and N2: Use of biological Nitrogen that consist of Rhizobium legominosarium bv. phaseoli strain 133-136-111 inoculation) and Zn (Zn0: Control, Zn1: 50 kg ha-1 ZnSO4 and Zn2: Use of biological Zn consist of Pseudomonas aeruginosa strain MPFM and Pseudomonas fluorescens strain 187 inoculum). Grain inoculation was done in shadow and after drying, inoculated grains were immediately cultivated. The measured properties consist of morphological growth characteristics, nodulation, nodule number and root colonization. Results: The results of experiment indicated that the effect of cultivar, P, N and Zn treatments was significant on studied parameters. The maximum of these parameters was obtained from Sadri cultivar, P2, P3, N2 and Zn2 bio treatments. The highest of studied parameters was obtained from P2Zn2, P2N2 and N2Zn2 treatments among the dual interaction effects. The concurrent inoculation of bean with mixture of mycorhizae + Azetobacter + R. leguminosarum + Pseudomonas significantly increased plant wet weight and nodule number. The triple interaction effect was significance on plant wet weight and nodule number only. The maximum amount of plant wet weight (45. 3 gram per pot) and nodule number per shrub (28 nodules) were obtained from P2N2Zn1 and P3N2Zn2 treatments respectively. Despite the lack of significance difference interactions between triplicate treatments, the maximum amount of nodule grade, colonization percentage and BNF, 16. 4, 44. 9 percent and 64. 4 Kg ha-1 respectively were obtained from P3N2Zn2 treatment. Also, the highest amount of plant dry weight, the number of germinated shrub and emergency speed, 22. 5 g pot-1, 4. 3 shrub pot-1 and 0. 54 shrub day-1 respectively were obtained from the combined treatments of P2N2Zn2 and P2N2Zn3. Conclusion: The maximum of studied parameters was obtained from P2, P3, N2 and Zn2 which represents the effective role of mycorrhizae fungi, phosphate and Zn solubilizing bacteria in increasing growth morphological properties, wet and dry weight, nodulation, colonization, BNF and reduction of P and N fertilizers. The studied parameters were increased with ombined using of double and triple of phosphate, nitrogen and zinc biotreatments. The combined use of phosphate, nitrogen and zinc, P2N2Zn2 treatment, is recommended to increase the morphological growth characteristics, nodulation and other studied parameters in this experiment.

Background and Objectives: Iron deficiency is one of the most common problems in the plant nutrition in arid and semi-arid regions soil, especially calcareous soil. Since iron oxides account for about 53. 8% of the slag, it can be used as a fertilizer. The use of copper slag of Sarcheshmeh Copper Complex sub-products was evaluated with organic compounds as the source of iron supply in calcareous soil. The purpose of this study was to study the effect of copper slag and organic compounds on the amount of extractable iron by DTPA and some characteristics of calcareous soil. Materials and Methods: In order to investigate the effect of slag on soil absorbable iron, an incubation test was performed for 3 months as a factorial experiment in a completely randomized design with three replications. The experimental factors consisted of 5 levels of organic matter (pistachio shell, cow manure 2 and 4% w/w and control sample) and 10 iron levels (copper slag, copper slag with sulfur, copper slag with sulfur and Thiobacillus, acid slag (each at two levels), Chelate Sequestrene and control sample). 10, 30, 60 and 90 days after incubation, changes in parameters such as pH, EC and iron content were measured by DTPA-TEA extractor. Results: The results showed that by applying the organic compounds' treatments during the incubation time reduced the iron extraction capability. The results showed that during the three-month incubation period, slag treatments increased soil EC. The highest amount of EC increase in slag treatment is 4 times the recommended value of the soil test based on the absorbable iron content of this compound with sulfur and Thiobacillus S4S° T at 2. 21 dS/m at the end of the incubation period. In the soil sample studied, proportional to the amount of slag, the amount of iron extracted by DTPA increased. However, during the incubation period, the iron extraction capability was reduced; however, the amount of iron increased significantly after 90 days from the beginning of incubation in S4S° T, S4S° and S4 treatments compared with the control. The interaction effect of slag treatments and organic compounds showed that the highest amount of EC and the lowest pH were related to 4% cow manure application with slag with sulfur and Thiobacillus. Meanwhile, the amount of absorbable iron in the soil from 1. 43 mg/kg in the control treatment of CS° reached 8. 17 mg/kg in the treatment of 4% pistachio shell as 4 times of the recommended value of the soil test with sulfur and Thiobacillus (P4S4S° T). Conclusion: Organic compounds during the incubation period led to a reduction in iron compared to the control sample. Slag of copper smelting has nutrient micro-elements, including iron, so that at high levels of slag consumption, the amount of iron increased, as well as the use of slag with sulfur, Thiobacillus and pistachio shell had the most amount of absorbable iron as a result, slag has the potential to be used as an iron source for plants.

Background and Objectives: The symbiotic relationship between endophytic fungi and plants due to its significant influences on the growth and yield of plants under the conditions of soil pollution has an effective role in heavy metal stress tolerance in plants. The purpose of this study is to investigate the effect of rice husk biochar and the endophytic fungus; Piriformospora indica; on some growth indicators (the shoot height, fresh weight and stem diameter) on corn and biological properties (microbial respiration and microbial biomass carbon) of a Zn-polluted soil under greenhouse condition. Materials and Methods: To do this research, suitable amount of soil from surface horizon (0-30) of a calcareous soil was collected, after air drying, samples were passed through a 2 mm sieve. This experiment was conducted in a completely randomized factorial design experiment with three factors including Zn (0, 50, 100, 200 and 300 mg kg-1 soil), rice husk biochar (0, 2 and 4 weight percent) and P. indica (non-inoculated and inoculation with fungi). Biochars were produced using the pyrolysis of rice husk (500 ° C for 4 h) in the limited oxygen conditions. For propagation of fungi and production of sufficient amount of spores, the isolates of the fungus were cultured and stored at 24 ° C in the incubator for 4 weeks. Before the corn was cultivated, after addition of biochar and zinc for 2 months, soil was incubated in field capacity moisture conditions at 25 ° C. After 8 weeks of plant growth some biological and morphological characteristics were measured. Results: At levels of 2 and 4 (% w/w) biochar, The shoot fresh weight, the shoot height and stem diameter of the control plants and non-inoculated with P. indica significantly increased by 4. 14 and 9. 18 percent, 3. 49 and 8. 43 percent, 3. 18 and 9. 25 percent respectively. Where as in the same conditions, shoot fresh weight of plants inoculation of P. indica was 5. 73 and 12. 76 percent, the shoot height was 4. 84 and 7. 67 percent and stem diameter showed a significant increase 6. 71 and 22. 61 percent compared to the control plants respectively. Also average microbial respiration and microbial biomass carbon in soil after corn harvesting in noninoculated of P. indica plants in condition at levels of 2 and 4 (% w/w) biochar of the control (without biochar) 39. 33 and 47. 83 percent and 12. 69 and 31. 30 percent significant increase respectively (P<0. 05). But the amount of these indicators of plants inoculation of P. indica at levels of 2 and 4 (% w/w) biochar of the control (without biochar) 40. 85 and 46. 63 percent and 2. 96 and 26. 48 percent significant increase respectively (P<0. 05). Conclusion: Application of 2 and 4 (% w/w) biochar resulted in significant increases in the shoot height, fresh weight and stem diameter on corn plant as well as microbial respiration and microbial biomass carbon of the soil. While this increase is more in the plants inoculation with P. indica fungi. Increasing biochar levels increases the nutrients absorption and improves plant growth. In addition, the P. indica fungi is likely to improve corn growth due to the production of growth stimulants and the increased nutritional capacity of the mineral nutrients for the plant. Also, the height, fresh weight and diameter of the shoots increased at levels of 50 and 100 mg kg-1 of Zn and decreased at higher levels (200 and 300 mg kg-1), possibly at high zinc levels due to decreased cytokinin, Iron, potassium and calcium, as well as increased ethylene and growth inhibitors inhibit corn growth.

Background and Objectives: One of the harmful effects of erosion processes is soil nutrient loss by runoff and sediment. Nitrogen and phosphorus are the main nutrients of soil in watersheds, but the accumulation of these elements in rivers and channels is the one of the most important issues in the nutrient soil loss, that can lead to the growth of aquatic plants, algae and led to Eutrophication phenomena. The aim of this study is to simulate the amount of total phosphorus and nitrogen that carried by runoff and sediment in the sub-basins of the Gheshlagh dam basin, mapping of nutrient loss in the basin and determining the critical sub-basins using the Soil and Water Assessment Tool (SWAT) model. Materials and Methods: To simulate the sediment load and the amount of soil nutrients loss, continuous and semi-distributed SWAT model was used. For this purpose, at first the DEM, network of streams, land use and soil maps were collected. The climate, soil and management databases were prepared for Gheshlagh dam basin. The observation data of runoff, sediment and water quality of 1993 to 2003 years were used for model calibration and those for 2004 to 2007 years were used for model validation using the SUFI-2 algorithm. Results: The results showed that the SWAT model has simulated discharge, sediment, phosphorus and nitrogen in Gheshlagh dam basin very well. For example, the R2, NS, r-factor and p-factor coefficients for monthly runoff calibration in Chehelgazi station were estimated 0. 80, 0. 72, 0. 78 and 0. 52 respectively and in Khalyfetarkhan station 0. 82, 0. 74, 0. 80 and 0. 54. The coefficients for phosphorus in Chehelgazi station are 0. 68, 0. 63, 0. 39 and 0. 55 respectively and in Khalyfetarkhan station 0. 69, 0. 66, 0. 55 and 0. 49. The organic nitrogen, nitrate, organic phosphorus, soluble phosphorus and mineral phosphorus were estimated to be 323, 12, 48, 0. 18 and 71 kg per hectare, receptively. The sub-basins with highest sources of soil loss are 50, 47, 43, 51, 48, 34 and 31 sub-basins, respectively, which are the source of about 30 percent of total nitrogen and phosphorus load in the basin. Conclusion: The results showed that the model can be effectively applied to determine the critical sub-basins with regard to nitrogen and phosphorus loss. The cultivated lands on steep slopes in west of basin have critical situation in terms of soil nutrient loss. In order to control soil nutrient loss of Gheshlagh dam watershed, the best management practices are reduction and control of nitrate and phosphate fertilizers, conversion of agricultural land to rangeland or forest in slopes and also creating a buffer zone along the river to reduce nitrogen and phosphorus losses entering to the reservoir basin.

Background and Objectives: Catena is defined as the range of continuous soil series which are at a toposequence and also called drainage sequence. The main objectives of this research were: 1. to study the combined effects of topography and drainage conditions and water table depth on formation and evolution of soils and 2. to investigate the hydromorphic and halohydromorphic soils of Miankaleh lowland area as wildlife habitat and tourist attractions. Materials and Methods: The study area is in the south-eastern Caspian Sea with a temperate climate, xeric soil moisture regime and thermic soil temperature regime. Three geomorphic surfaces determined in the area are consisted of hillslopes, alluvial plains and lowlands. Five representative pedons were investigated using present soil maps of the area along North-South transect. Results: The low-lying soils near sea were classified as Aquisalids and Halaquepts and gleization has occurred. Based on field observations and previous studies it appears that this region has come out of the water during the past century. In the alluvial plain in agricultural lands, Haplaquolls and Haploxerepts were dominant with high organic matter accumulation. In Haplaquolls accumulation of clay and gleization were observed. In Haploxerepts, vertic properties were dominant. Finally in hillslopes of the north-facing slope of Alborz under forest vegetation Haploxeralfs were formed with argillic horizon and decalcification has occurred. The clay mineralogical results showed that illite was dominant clay mineral in low lying and alluvial plain soils, but in hillslope under forest vegetation smectite is dominant mineral. Vermiculite is also found in the soil of hillslopes well. Due to lack of the necessary conditions for the formation of kaolinite, this mineral is inherited from the parent material. The presence of illite and chlorite minerals in area soils have a hereditary origin. Conclusion: In hillslopes due to greater leaching and forest cover, weathering was intense and more smectite and vermiculite was formed. Intensive decrease of chlorite in the pedon in the forest, because of higher weathering is rational. In this pedon, the percentage of smectite clay mineral in the subsurface horizon is significantly higher than the soil surface. In alluvial plain soil the amount of illite reduced and smectite was higher that could be the result of smectite formation from the weathering of illite. In low lying soils due to aquic condition, authigenesis of smectite has occurred and smectite in these soils are also found to be significant. As a result, smectite has two pedogenic sources i. e. neoformation from soil solution and transformation from illite and chlorite minerals.

Background and Objectives: Modelling of environment and landscape quality involves the consideration of a number of factors, including existing vegetation cover, man-made constructions, topography and soil attributes. Today, the goal of assessing the quality of the environment and the landscape is to determine the indicators and criteria by which they can preserve, restore and reconstruction the landscape. In fact, in this way, it is possible to preserve aesthetically pleasing landscapes and restore other landscapes. The objective of this study was to evaluate the quality of environment and landscape in the riverside parks of Ahvaz using fuzzy knowledge-base. Materials and Methods: To do this research, two depths of 0. 30-0. 30 cm were taken and soil samples were transferred to laboratories for laboratory studies and exposed to air and dried and soil properties, slope percentage, visual aesthetic elements of man-made and vegetation cover were measured. A visual assessment was used to investigate the plant factor (resistant and effective on aesthetics) and human elements. For this purpose, 150 photographs of coastal parks were prepared and rated by space experts. Finally, the fuzzy knowledge-base with six parameters (salinity, gradient, soil texture, man-made, resistant plants and soil fertility) and seven models were used to study and model the quality of environment and landscape of the riverside parks of Ahwaz. Results: The results of this study indicated that the average amount of soil texture, bulk density, mean weight diameter (MWD), soil salinity, sodium adsorption ratio, organic matter, Olsen phosphorous, slope, visual aesthetic of vegetation and man-made elements were sandy loam, 1. 67, 0. 33, 10. 96, 24. 94, 2. 42, 17. 81, 3. 7, 2. 26 and 0. 12 in this parks, respectively. The visual aesthetic elements of man-made and vegetation cover is also low due to lack of this elements. According to the experts of soil science, salinity, gradient, soil texture, man-made, resistant plants and soil fertility are the most effective variables for classifying the environment and landscape, so these variables can be important indicators for assessing the quality of green spaces and environment and landscape. The fuzzy knowledge-base models used in quality classification of the environment and landscape of Ahvaz riverside Parks showed that 38. 7, 58. 8 and 2. 5 percent have low, medium and high degree of quality class, respectively. Conclusion: These results showed that the soils in this parks have saline & sodic properties with high density and low aggregate stability. Saline & sodic properties and soil erosion has been recognized as the most important limiting factors in the area with low and medium quality class. Therefore, drainage systems construction and soil leaching for reduce salinity and planting of tolerant vegetation cover to control of environmental stress were recommended for restoration of green space in this area.

Background and Objectives: Digital soil mapping (DSM) predicts soil variability based on the relationship between soil classes and auxiliary information. Therefore, it is expected that if two regions have similar auxiliary information, the model developed to estimate soil variability for one of these regions could be generalized to the other. The aim of this study was to predict soil classes up to great group level of Soil Taxonomy (ST) and Reference Soil Group (RSG) level of World Reference Base for Soil Resources (WRB) across the area with little soil data (recipient site) on the basis of constructed model in area that has sufficient soil data (reference site) using DSM approaches in the Shahrekord plain of Chaharmahal-Va-Bakhtiari Province. Materials and Methods: The reference and recipient sites are located in the Shahrekord region of Chaharmahal-Va-Bakhtiari Province. The Mahalanobis distance is used to determine the distance between the mean of the reference’ s soil forming factors and the recipient’ s soil forming factors (Mallavan et al. 2010). The reference site for this study was surveyed using digital soil mapping approaches at semi-detailed scale (i. e., raster maps with pixel size 50×50 m) up to family level by Mosleh (2016). Different machine learning algorithms consisting of artificial neural networks (ANNs), boosted regression tree (BRT), random forest (RF) and multinomial logistic regression (MLR) were considered for each soil taxonomic level to identify the relationship between soil classes and auxiliary information. Fifteen pedons were excavated at the recipient site with 750 m intervals. All the pedons were described and the soil samples were taken from different genetic horizons, air dried, crashed and passed through a 2 mm sieve. The soil samples were classified the soils according to the Soil Taxonomy (Soil Survey Staff 2014) and WRB (IUSS Working Group WRB 2015) up to great group and Reference Soil Group levels, respectively. Results: The results showed that the Mahalanobis distance at the reference and recipient sites is equal. Therefore, the two studied sites are entirely similar and can be considered as Homosoil. Summary statistics of auxiliary information for the reference and recipient sites indicated that the difference between the mean of the reference’ s soil forming factors and the recipient’ s soil forming factors is negligible. Extrapolated models across the recipient site lead to similar results with the reference site. These results include: (i) no significant differences were observed between different models to predict soil classes based on the ST system; (ii) OA values showed a decreasing trend with increasing the taxonomic levels for all the studied models (Figure 3); (iii) the MLR model has the highest performance to predict the RSG. Conclusion: The results indicated that DSM could be used for prediction of soil classes in the Homosoil framework (both sites have similar auxiliary information or soil forming factors). It is expected that the accuracy of predictions is accrued if there is a high agreement between the reference and recipient sites in terms of the auxiliary information.

Background and Objectives: Wind erosion and sand dune movement as one of the most important reasons for desertification and land degradation in arid and semiarid areas, incorporates significantly in soil and natural resources damages, air pollution, health threat and socio-economic disturbances. Stabilization of sand dunes is therefore very important. One of the fundamental methods to control wind erosion and to stabilize sand dunes is the use of mulches on the soil surface. Providing a simple method using cheap materials for preparing a durable mulch in order to decrease soil losses is of high importance. In recent years the use of industrial cheap and secure wastes as mulches are attracting more attention. The present study was conducted with the aim of investigating the effect of micro silica slurry as a byproduct in the manufacture of silicon or ferrosilicon alloy, on soil losses of sand dunes. Materials and Methods: Therefore, an experiment was carried out in factorial arrangement as a completely randomized design at 3 replicates. Wind erosion meter (wind tunnel) was used to measure the soil losses. For preparing the treatments, trays with the sizes of 100 cm (length) × 30 cm (width) × 2 cm (depth) were filled with sand samples and their surfaces were level. Filled trays with sands were used for mulching. Micro silica slurry was sprayed over trays in 4 coverage percentages (25%, 50%, 75% and 100%), two thicknesses (one and two-layer) and two times (7 and 60 days). Sand trays were then weighed and exposed to a wind speed of 15 ms-1 for 20 minutes (similar to the intensive wind flows of the studied area). Trays were weighed again and the amount of eroded materials were determined according to the weight differences of trays. Results: Results showed that soil losses decreased significantly (P≤ 0. 01) with the increase in coverage percentage and thickness of micro silica slurry. Soil losses decreased more than 2 times at the micro silica slurry coverage surface of 100 percent in comparison with the coverage surface of 25 percent and soil losses decreased 55. 3% in treatments containing two layers of micro silica slurry in comparison with one layer treatments. The 50 percent micro silica slurry with the coverage percentage of 100% and tow layer thickness represented the best results in decreasing soil losses. Conclusion: Despite the significant effect of micro silica slurry mulch on decreasing the soil losses, its efficiency has been decreased during the time. But as the soil losses are low in treatments containing two layers, it seems that more soil losses can be controlled by increasing the mulch thickness.