Journal of Soil Management and Sustainable Production
Year:2015 | Volume:5 | Issue:3|Papers Count:17

Background and Objectives: Soil pollution by heavy metals is considered as important environmental problem that received more attention nowadays. Copper is one of essential microelements for plant that in high concentration will cause soil pollution and toxicity effects on plant. This element can accumulate in soil via mining activity and using pesticides. Many copper mines are in use in Iran and around the world. Ornamental plants have a special position in beautifying the industrial and urban landscapes and recognition of hyper accumulator species for amendment of contaminated soils has a considerable value.Material and Methods: The effect of different levels of copper (0, 50, 100, 200, 400 and 800 mg copper per kg soil) from copper sulfate source in presence or absence of mycorrhiza fungi on growth characteristics of Zinnia flowers were studied in this research. The selected mycorrhiza were isolated from Zinnia plant root with high colonization percentage and had also colonization percentage of more than 80 percent with clover and sorghum. A factorial experiment with a completely randomized design with 5 replications was conducted in greenhouse conditions. The Plants were harvested after a period of 70 days and some parameters such as shoot and root length, leaf number, leaf area, root volume, shoot and root dry weight, root mycorrhizal colonization percentage and copper concentration in shoot and root were measured.Results: The results of field evaluation showed that root mycorrhizal colonization of Zinnia were up to 96 percent and the colonization percent was more in sandy soil and also salinity had significant negative effect on colonization percent. The greenhouse results showed that the effect of mycorrhizal fungi on all parameters was significant at the 1% level and Mycorrhizae enhanced shoot dry weight, root fresh and dry weight and root copper concentration by 91, 83, 92 and 71 percent respectively than non-mycorrhizal control. The effect of copper levels were significant on shoot length at 5% and on the other parameters at 1% percent level. The level of 800 mg/kg of copper decreased the number of leaves, root length, mycorrhizal colonization percentage and leaf area by 39, 31, 25 and 97 percent compared to control respectively. The interaction between copper and fungi had no significant effect on shoot length and leaf area, but were significant on leaf number at 5% and on the other parameters at 1% level. Using mycorrhizal inoculants decreased the negative effects of copper application and resulted in a considerable difference between measured index.Conclusion: The results showed that increasing in copper application resulted in increasing copper concentration in shoots and roots of plants and the concentration in roots of inoculated plants were higher and in shoots were lower than none inoculated. However inoculation of plants with mycorrhiza resulted in a higher accumulation of copper in roots and decreased its translocation to shoot, but total uptake of copper in shoots of inoculated plant was significantly higher. So based on the result of this research, this ornamental plant can be used for remediation of polluted soils by high concentration of copper.

Background and Objectives: Many factors are affecting absorption of heavy metals. So that the type and amount of soil colloids, controller parameters such as pH, ion concentration of the solution, the concentration of metal cations, the existence of competing metal cations and organic and inorganic ligands are involved (1). Given the importance of arsenic and cadmium, as one of the most serious environmental pollutants and the effects of these metals on human health and animals and entering the food chain, investigating the problem of arsenic and cadmium and the response of different plant species faced with various levels is important. In this study the effects of some soil properties on uptake of arsenic and cadmium bySilybum marianumwas studied.Materials and Methods: The surrounding area of asphalt plant of Kalaleh city in Golestan province, was divided into 6 pieces (A, B, C, D, E, F), with an area of approximately one hectare. Plots A and D on both sides of the river, are the nearest areas to asphalt plant. Also a Non-polluting area as a control was considered. Soil samples of 0-30 cm soil depth in 3 replicates were collected randomly with plant samples in 3 points of each region and 3 were repeated at every point. Samples in a place closed and in the open air dried and then crushed using mechanical means and then from 2 mm sieve passed. Some soil physicochemical parameters such as pH, salinity, cation exchange capacity, organic carbon and the amount of arsenic and cadmium in the soil andSilybum marianum were measured.Results: Arsenic accumulation in plants collected from plots A and D (6.83 and 6.18 mg arsenic per kg of plant dry weight) is greater than the plant permitted limit. The highest uptake of cadmium was observed in plot A (1.58 mg Cd per kg of plant dry weight) and then plot D (1.41 mg Cd per kg of plant dry weight) that in both plots were more than permitted standard limits.In the present study, between the CEC and soil organic carbon, with arsenic and cadmium uptake by the plant, a negative correlation was observed, so that areas with lower CEC and soil organic carbon, arsenic and cadmium levels were higher in plants.Conclusion: In the present study, the arsenic amount in plants in areas with high acidity and salinity was higher. Considering that bioaccumulation factor in the roots and shoots for both metal, in all plots was smaller than one, the plant cannot be as a hyper accumulator for these metals.

Background and Objectives: Soil pollution with heavy metals is increasing significantly and created major environmental problems worldwide. Cadmium and Lead are among the heavy metals entering into the soil through various means such as the burning of fossil fuels, municipal solid waste, chemical fertilizers, pesticides, sewage sludge, etc. Several studies have shown that the use of phosphate fertilizers resulted in the transfer of heavy metals to agricultural crops. On the other hand, potential of calcareous soils in the stabilization of P have caused the need for using natural modifier along with phosphate fertilizers for increasing their effectiveness.Materials and Methods: In order to compare the native phosphate rock and imported triple superphosphate treated with sulfur and Thiobacillus in transferring lead and cadmium into Pistachio seedling, cadmium and lead contamination in imported triple superphosphate and native rock phosphate samples were first analyzed and then, the ability of the two phosphorus fertilizers treated with elemental sulfur and Thiobacillus to accumulate lead and cadmium in pistachio seedlings was evaluated. For this purpose, a pot experiment was conducted as factorial based on completely randomized design with three replications including three levels of phosphate fertilizers (control (P0), 2000 mg phosphate rock per kg soil (PR) and 67 mg triple superphosphate per kg soil (TSP)), two levels of elemental sulfur (0 (S0) and 2000 mg sulfur per kg soil (S1)) and two levels inoculums (no inoculation (T0) and Thiobacillus inoculation (T1)). Cadmium and lead concentrations in shoots and roots were measured and also analyzed in both phosphate fertilizers.Results: Results showed that the mean value of cadmium concentration in imported triple superphosphate with 17.75 mg Cd/kg fertilizer was about 5 times higher than cadmium concentration in native rock phosphate with 3.05 mg Cd/kg fertilizer. Lead concentrations in imported triple superphosphate and native rock phosphate were found 0.932 and 1.05 mg Pb/kg respectively and no statistically significant difference was observed between two fertilizers. Application of triple superphosphate had the greatest effect on shoot cadmium concentration (10.5%) compared to the phosphate rock. Using Thiobacillus increased significantly shoot cadmium concentration (6%) and cadmium translocation factor. Application of phosphate fertilizers decreased lead concentration in shoot and the highest lead concentration was observed in the control treatment.Conclusion: In general, the results indicated that the application of phosphate fertilizers not only didn’t cause lead transmission to the plant but also inhibited lead entrance to the plant, but the use of sulfur and Thiobacillus along with phosphate fertilizers increased lead uptake in plant in comparison with application of only phosphate fertilizers, so that, it was classified with control treatment in one group. Imported triple super phosphate fertilizer also raised shoot cadmium concentration up to 10.5% in compared to phosphate soil because of high cadmium contamination. A very little Cadmium pollution in phosphate soil suggests the good quality of phosphate soil sources in our country compared to imported triple superphosphate. However, further studies in this context, will provide more specific results.

Background and Objectives: Soil pollution by heavy elements such as cadmium, zinc and lead, because of adverse effects of the elements on human health and living organisms, have been a matter of concern in recent decades. Lots of effort has been made to block the entrance of these elements into natural and biological cycles. For this purpose, different methods for decreasing the availability of the elements have been assessed and chemical and physical approaches have been used. But the methods are expensive and sometimes destroy the physical and chemical properties of soils. Thus, it is better to use biological methods to decrease the availability of heavy metals in soils since these methods are inexpensive and environmentally friendly.Materials and Methods: An experiment was aimed to assess the effects of biological fertilizers on yield and yield components of tomato under cadmium stress. This experiment was factorial and had a completely randomized design and three replications. Three combinations of biological fertilizers including M1: Azotobacter bacteria + Mycorrhizal fungi +Azosperillium bacteria, M2: Mycorrhizal fungi + Bacillus bacteria + Pseudomonas bacteria + Azotobacter bacteria, M3: Pseudomonas bacteria + Azotobacter bacteria + Mycorrhizal fungi and M0: treatment without biological fertilizers (control) was used. The levels of soil cadmium were 0, 5, 10, 20, 40 and 80 mg Cd/kg soil.Results: The results of this study showed that application of biological fertilizers increased yield and growth indices of tomato and caused the concentrations of micronutrients to increase in aerial part and the root of this plant. The highest yield was obtained from the M1 treatment, so that it was significantly different from the other treatments. By contrast the M3 treatment was not significantly different from the control. The yield and growth indices of tomato plant decreased as the levels of soil cadmium increased. The cadmium level of 80 mg Cd/kg soil decreased tomato yield by 67% compared with control.Conclusion: The results of this research showed that inoculation of soils with biological fertilizers decreased the adverse effects of cadmium on tomato plants and due to higher yield and performance of the M1 treatment, this treatment is recommended for decreasing the adverse effects of cadmium in polluted soils.

Background and Objectives: According to the difficulty of the soil erodibility concept, some indicators have been used for its evaluation. Climate as one of the soil formation factors, has a major impact on the indicators. The present study was done in order to determine the effect of different climates on physical indicators of the quality of loess soils in Golestan province.Materials and Methods: In order to the study, a climosequence of north-east to south-west in the sloping loess hills of the Province with pasture and in different climate conditions was chosen. Samples were taken from seven areas with six replications and from the depths of 0 to 30 and 30 to 60 cm along the climosequence. Amezketa, plasticity, soil specific surface, cation exchange capacity and soil texture indicators were measured.Results: The results showed that the changes in some of the indicators in the climosequence follow a particular trend. The changes in the average of the Amezketa index, along the climosequence, was variable from 0.05 to 0.23 and do not follow a specific trend. The changes in the soil specific surface were variable from 51.95 to 145.52 m2/gr. The changes in the plasticity, soil specific surface and cation exchange capacity along both transect increased and Amezketa index, by increasing the rainfall, increased along climosequence.Conclusion: According to the results, aggregate formation and aggregate stability with the soil particle size ratio, caused the changing of the erodibility indices of loess soils.

Background and Objectives: Soil saturated hydraulic conductivity is the most important physical parameter, but its measurement often is difficult because of practical and/or costrelated reasons. In this research, expert system approaches with one type of the nonparametric lazy learning algorithms, a k-nearest neighbor (k-NN) algorithm, was compared and tested to estimate saturated hydraulic conductivity (Ks) from other easily available soil properties.Materials and Methods: In this research 151 soil samples were collected from farmlands around Bojnourd and saturated hydraulic conductivity (Ks) was estimated from other soil properties including soil textural fractions, EC, pH, SP, OC, TNV, rs and rb. To evaluate artificial neural network systems all the data were divided into 3 parts, 50% for training, 25% were allocated for the test and other data for validation. Design of MLP models (Multilayer Perceptron) was performed by sigmoid functions and hidden layer. ANN for all models was selected with Levenberg-Marcoardet algorithm to training as a hidden layer threshold logsig function for hidden layer and tansig for output layer.Results: Results showed that the accuracy of the parameter estimation, using parametric method of artificial neural network to compare with k-nearest neighbors for terms of all the parameters (with r=0.97, EF=0.946, RMSE=8.798, ME=28.446 and CRM=-0.144) compared to other methods input models was acceptable.Conclusion: The results showed that different techniques have estimated, hydraulic conductivity coefficient partially. The non-parametric method k-nearest neighbor, focus on the estimation of the regression line 1: 1 has been studied more than the other methods. The best result was for artificial neural network method with all information bank. Performance index knearest neighbor method (EF=57 to 71%), is powerful indication of this technique for estimation of soil hydraulic conductivity based on other easily available parameters, including particle size distribution, soil saturation extract, electrical conductivity (EC), saturation percentage of soil (SP), the organic carbon (OC), total of neutralizing value (TNV), bulk and apparent specific density of soil. ANN method can be used to estimate saturated hydraulic conductivity especially when new data set available.

Background and Objectives: Nowadays soil contamination with heavy metals is considered as one of the most serious environmental concerns. Among the heavy metals, lead due to inverse impacts on human health and substantial environmental problems causes major concern. Accordingly, this study was carried out with the aim of assessing the ability of different corn cultivars in the accumulation of lead in their parts (shoot and root) and transfer it from the roots to the shoots.Materials and Methods: The Experiment was conducted in a greenhouse condition and was tested in a factorial experiment in completely randomized design with three replicates. Lead chloride salt (PbCl2) was used for contaminated soil. Treatments included four lead levels (0, 100, 200 and 400 mg Pb.kg-1) and eight varieties of maize (260, 301, 302, 370, 500, 604, 647 and 704). Shoots and roots height was measured by a metal ruler. To determine Pb concentration of plant samples, dry ashmethod was used and after extraction Pb concentrations were measured in roots and shoots by atomic absorption spectroscopy (Shimadzu-AA6400).Results: According to the obtained results, dry weight of shoot and root decreased with increasing lead-chloride concentration in the soil. Moreover, it was observed that in most varieties (except for 260), the lead-chloride (especially for 400 mg/kg) caused reduction of the shoot height and root length compared to the control treatment. The results showed that the amount of lead accumulated in the roots was higher than shoots and with increase of lead levels in the soil, concentration of lead in plant tissues (roots and shoots) has significantly increased (P<0.05). The highest lead concentration of shoot (54.33 mg/kg DM) and root (325.11 mg/kg DM) were observed in 400 mg/kg and also both of them were in the variety of 704. The amount of transfer factor and bio-concentration of shoot and root biomass were less than one.Conclusion: Results showed that maize varieties studied in the current experiment accumulated more Pb in roots compared to shoots. Therefore, the amount of transfer factor (TF) was less than one. However, Pb can be toxic to humans and animals causing of health effects. So, it should be considered, especially in land under maize cultivation that is used for livestock feed.

Background and Objectives: The presence of heavy metals in the environment is causing ever-growing concern due to their toxicity, carcinogenicity and non-biodegradability. Nickel may enter and accumulate in agricultural soils through various ways. One of the most important chemical processes which affects the behavior and bioavailability of heavy metals is sorption of metals from liquid phase on the solid phase. This process controls the concentration of metal ions and complexes in the soil solution and can influence their uptake by plant roots. Sorption isotherm is a useful method to study metals retention in soils as it gives much useful information about sorption capacity of soils. The aim of the present study was to investigate the sorption properties of Ni by calcareous soils of Iran and its relation with some soil properties to better understand the fate of this metal in calcareous soils.Materials and Methods: Nickel (Ni) sorption characteristics in 20 calcareous soils of Iran were investigated in a range from 5.87 to 751.23 mgL-1 Ni concentration in solution using sorption isotherms of Langmuir, Freundlich and Redlich-Peterson. The “Curve Expert” software was used to fit the models of sorption isotherms. The high coefficient of determination (r2) and low standard error of estimate (SEE) were used as a criterion for selecting the best model.Results: The Ni sorption isotherms could be fitted by the Freundlich model (r2=0.92-1.00; mean 0.99). The dimensionless parametern that may indicate the sorption site energy distribution for different soils was between 2.07 and 3.15 and average of 2.46. Also the coefficient of determination and standard error of estimate showed that adsorbed behavior of Ni by calcareous soils can be described by Langmuir adsorption equation (r2=0.94-0.99; mean 0.98). The maximum sorption of studied soils for Ni ranged from 1369 to 5378, with average of 3605 mg/kg. The coefficient of bonding energy (KL) in different soils was between 0.008 and 0.029 with an average of 0.015 L/mg that indicate narrow range of this parameter among the studied soils. The distribution coefficient (Kd) ranged from 22.6 to 122.5 with average of 54.8 L/kg.According to the coefficient of determination (r2=0.94-1.00; mean 0.99) and standard error of estimate (SEE=47.9-163.3; mean 96.9), the Redlich–Peterson equation achieved the best fit to the data of Ni sorption in studied soils. The maximum Ni sorption (qmax) correlated with organic matter (r2=0.50, P<0.01), clay content (r2=0.75, P<0.01) and cation exchange capacity (r2=0.76, P<0.01). The coefficient of Ferundlich (Kf) positively correlated with organic matter and clay content while Ridlich-Pterson parameters were not correlated with the soils properties.Conclusion: The isotherms of Ni sorption showed the completely nonlinear behavior for all soils. Freundlich, Langmuir and Redlich-Patterson equations well fitted to Ni sorption data. The results of this study showed that the cation exchange capacity, clay and organic matter content of soils are the most important properties which could affect Ni sorption while Ni sorption was not affected by calcium carbonate equivalent (CCE).

Background and Objectives: Plants growth in agricultural soils are affected by several biological factors. Plant growth promoting bacteria can improve growth and yield of agronomic plants through direct and indirect mechanisms. Minimizing consequences of using high amount of fertilizers and obtaining sustained level are the aims of sustainable agriculture. Using microorganisms due to improving soil fertility and nutrients uptake, lead to increase growth and yield of plants and ameliorate soil health. The aim of this research was to isolate and purify bacterial isolates from animal manures, to evaluate their plant growth promotion characteristics and identify the selected isolates.Material and Methods: In order to characterize growth promotion properties of bacteria in this study, 10 samples of animal manures from different regions were collected.27 isolates based on halo production, growth rate and morphological characteristics in NBRIP medium were purified and then their typical PGP including auxin, Siderophore, HCN production, insoluble phosphates solubilization and secretion of protease, Cellulase, a-amylase and phytase were evaluated and finally selected isolates based on 16SrRNA were identified.Results: Among all of the isolates, maximum phosphorous from tri-calcium phosphate (373 mg/l) and aluminum phosphate (13.3 mg/l) was released by isolates NO.7. Significant negative correlation (r=-0.86, P£0.01) between maximum solubilization of tri-calcium phosphate and pH was observed. Isolate NO.21 produced greatest amount of auxin (52.8 mg/l). Only isolates NO.30 and 53 were positive in HCN production. Among 27 isolates only three of them had the ability to secret protease, cellulase and a-amylase. The utmost halo was measured by isolate NO.49 in production of these three enzymes. Evaluation of extracellular phytase production showed that only 6 isolates were capable to produce the enzyme. The analysis of the 16S rRNA of the selected isolates showed highly similarity to bacteria belonging to the generaEnterobacter, Sphingobium, Serratia. Only one of the three selected isolates produced weak halo in CAS-agar medium and another two isolates didn’t show the siderophore prodction capability.Conclusion: Plant growth promotion characteristics of bacterial isolates, in this research, showed that some of the isolates had the potential to be used as PGPB. Those isolates capable of producing protease, amylase and cellulase enzymes not only have usability in agriculture but also because of the importance of this group of enzymes, especially protease and amylase in industry, can also be considered.

Background and Objectives: Argillic horizons are subsurface horizons which contain considerably more phylosilicate clays than upper horizons show evidences of clay illuviation.In some soils evidences of illuviation of clay are obvious, whereas, some soils due to weathering and insitu formation of clay particles, evidences of clay illuviation disappear. Under such circumstances, as a key tool, micromorphology properly helps for recognition of argillic horizons.Materials and Methods: In this study argillic horizons in calcareous soils of a semiarid region, with xeric and mesic soil moisture and temperature regimes, in the west of Urmia Lake were studied. Thus, a toposequence in different physiographic positions including piedmont plains, plateau, hills and mountains was investigated. In each land type, three soil profiles were dug and described and their morphological properties were determined. Disturbed samples for physical and chemical studies and undisturbed and oriented samples for micromorphological studies were obtained from characteristic horizons. Physical and chemical properties of soils were determined using standard methods. In order to perform micromorphic studies, thin sections with the thickness of 25-30 microns were prepared from undisturbed and oriented samples and were studied using polarizing microscope under cross polarized (XPL) and plain polarized (PPL) lights.Results: Field observations revealed the presence of argillic horizons only in piedmont plains and plateau land types and the physico-chemical and micromorphological results confirmed their presence as well. According to the results, argillic horizons had redder Hue, higher clay content and ratio of fine clay to total clay than the overlying horizons. Thin section observations showed that clay skins are present as coatings with a thickness of 0.08-0.34 mm on the faces of voids and skeletal grains and comprise 2-7% of thin sections of argillic horizons and in some cases, they have filled all of pore spaces. Regarding to semiarid climate of this region and presence of high quantities of calcium carbonate equivalent in these soils, the genesis of argillic horizons in this region was probably related to the wetter past climate and thus, argillic horizons in these soils are relict features from a wetter climate in lower Quaternary. In some of these studied soils clay coatings have been engulfed by calcium carbonate and in some cases, they have been disappeared completely. The engulfment of clay coatings by calcium carbonate shows that the climate of this region has been changed from wet to arid which caused to calcium carbonate accumulation in argillic horizons and changing them to the complex argillic- calcic horizons and thus, these soils are polygenetic.Conclusion: Presence of argillic horizons in these soils shows that this region was geomorphologically stable and the stability of this area along with other suitable condition for translocation of clay particles in profile (such as wetter climate) have led to formation argillic horizons in this area.

Background and Objectives: Field saturated hydraulic conductivity (Kfs) is one of the most important soil properties that considerably contribute to soil quality. However, specifically in the structured soils, the measurement of Kfs is difficult and time-consuming. Therefore, verifying the simple and fast methods for Kfs measurement is needed for effective soil monitoring. This study was conducted to investigate the effect of ring size (rings with diameters of 5.5, 10.88, 16 and 31.8 cm) on the Kfs measured with simplified falling head (SFH) single ring method in a structured clay loam soil. Furthermore, the effect of conventional tillage on Kfs was assessed and the Kfs measured with double ring (DR) method and SFH procedure was compared.Materials and Methods: The simplified falling head (SFH) method of rings with diameters of 5.5, 10.88, 16, 27.83 and 31.8 cm was used. In DR method diameter measuring 83.27 cm and diameter ring buffering 50 cm and infiltration with way costant head was measured. Factor of discrepancy between the values of field saturated hydraulic conductivity (Kfs) was measured with different ring sizes with model simplified falling head (SFH) single ring and traditional double ring (DR) methods. Statistical analysis in a completely randomized design between DR method and different sizes were used in SFH. The comparison of the level of five percent by SNK using SAS (9.1.3) was performed.Results: Results showed that while the ring size affected the measured Kfs, the discrepancy between Kfs results of given ring size compared to the smallest ring size (d=5.5 cm) was practically negligible (factor of discrepancy£0.27). The effect of tillage operations on the measured Kfs was substantial (discrepancy between Kfs results of 2.1 to 3.1). The SFH and DR techniques yielded statistically different means of Kfs. However, the discrepancy between the Kfs values obtained with the SFH method using the largest ring size and the Kfs values determined with DR method was practically negligible (factor of discrepancy<0.37). The coefficient of variation of Kfs values obtained with DR was also higher than the SFH measurements.Conclusion: The duration of the infiltration runs with SFH approach was appreciably shorter than the DR method. In conclusion, the mean Kfs values obtained with SFH technique were appropriate to monitor the effect of tillage. Further studies are needed to test the suitability of SFH technique to monitor hydraulic conductivity of various soils for different purposes.

Background and Objectives: Soil and water salinity are the major limiting factors for plant growth and crop production. Water and soil salinity almost limit plant growth through increasing osmotic pressure, specific toxicity of some ions such as sodium and color and nutritional imbalance. In addition, salinity stress reduces root and plant growth via increasing hormone level. One of the strategies to deal with salinity is inoculation of seeds with plant growth-promoting rhizobacteria (PGPR).Materials and Methods: The efficiency of four strains of Fluorescent pseudomonads was determined in view of the concentration of nutrients nitrogen, phosphorous and potassium in rice under irrigation with saline water. In this research, a pot experiment was carried out as factorial experiment in a completely randomized design with four replicates. Treatments included five levels of saline irrigation water (700, 1400, 2800, 4200 and 5600 ms/cm from sea water source) and four inoculations (P. putida 4, P. putida 11, P. putida 108 and P. fluorescens 169) and control. Rice was transplanted in pots after they were inoculated with desired strains.During growing period, the pots were irrigated with treatment of salinity up to saturation point.In the flowering stage, flag leaf samples were collected to determine nitrogen, phosphorus and potassium concentration. The amounts of nutrients in seed samples were determined after rice harvesting.Results: Results showed that the maximum nutrient concentration measured in leaf and seed of rice were observed in salinity 700 ms/cm and increase in salinity level led to decrease in nutrient concentration in the leaf and seed significantly (P<0.01). Inoculation with test strains, on the other hand, led to increase in nutrient concentration. Results also indicated that interactions between bacteria and salinity significantly raised nitrogen and phosphorous level in the rice leaf and seed (at P<0.01). There were no significant differences between strains in N content of leaf at all salinity levels.Conclusion: Inoculation of rice with various strains of bacteria Fluorescent pseudomonads and putidaaffected the concentration of nutrients under irrigation with saline water in rice and caused to increase these elements more than control. Therefore, in saline conditions, strains of Fluorescent Pseudomonas can be used as growth promoting bacteria of rice plant.

Background and Objectives: Effective use of water in agriculture is one of the most important precedence in world especially in arid and semiarid regions. Using superabsorbent materials for holding moisture in soil, prevention from its evaporation and to increase irrigation efficiency is one of the practical methods in soil and water science. Pumice is one of these superabsorbent materials that is a non-crystalline mineral made up of aluminum silicate. This mineral have high ability for moisture absorption and holding. This research was performed in the Khajeh research station on the basis of randomized complete block design with three replications in the plots with dimension of 4´5 meter to investigate the effect of different amounts of pumice on water holding capacity in the soil, growth and yield of spring safflower in rainfed condition.Materials and Methods: Experimental treatments were five rates of pumice (A: 0, B: 5, C: 10, D: 15 and E: 30 ton ha-1). Before cultivation, amounts of pumice was calculated for each plot and then mixed with soil to depth of 20 cm. Then, seeding cultivation was performed and the number of germinated seeds was determined at first ten days of cultivation. Soil volumetric water content and plant height was measured at various times during growth season and 1000 grain weight and grain yield of safflower was measured in the end of the growth season.Results: The results showed that in treatment A (no pumice), mean volumetric water content through growth period was lowest (3.87%). With increasing pumice in soil, volumetric water content stored in soil showed considerable increment, as in treatment E (30 ton ha-1 pumice) which obtained highest amount of soil moisture (12.20%). Treatment of 30 ton ha-1 pumice increased volumetric water content and measured plant parameters more than other treatments.This treatment (30 ton ha-1 pumice) led to significant increase 47, 43 and 74 percentage respectively in germination, 1000 grain weight and grain yield (P<0.01) and significantly increased 14 percentage of plant height (P<0.05).Conclusion: Adding pumice to soil improves soil physical conditions (total porosity, water holding capacity of soil and prevent the formation of crust on the soil surface) and leads to increase in growth and yield of plants. Therefore, pumice with having light and porous texture and high ability in water absorption, leads to increase in soil porosity, decrease bulk density and decrease in crust formation in soil surface and it provides suitable physical condition for root growth. Also with absorption of rain water and keeping moisture in soil, prevents from water deficit stress of plant through growth season. On the other side, because pumice compared to its similar material (perlite and vermiculite) is very inexpensive, so its application in wide areas in rainy conditions for increasing yield and production can be economic.

Background and Objectives: Drought, high and low temperatures are the most important abiotic stresses in chickpea cultivation.90 percent of world chickpea is produced where the production depends on rainfall and drought in the late season, is the main growth limiting factor. Improving plant root characteristics (root length and root volume) is one of the ways to increase drought tolerance in chickpea. Mycorrhizal symbiosis increases drought resistance of host plants through different mechanisms such as improving plants nutrition in drought stress, leaf water potential, length and depth of roots, root contact with the soil surface and plant metabolites balance. The aim of this study was to investigate the effects of drought and AM fungi on some chickpea growth indices.Materials and Methods: To study the effects of water stress and mycorrhizal fungi inoculation on chickpea, a greenhouse experiment as split plot was carried out in Maragheh Agricultural Research Station in a non-saline calcareous soil. Soil moisture levels, namely: Field capacity, (moisture in the 0.3 bar tension) moderate drought (moisture in the -5 bar tension) and severe water stress (water content in the -10 bar tension) were considered as main plots and inoculation with mycorrhizal fungi (Glomus mosseae, G. intraradices both fungi and un-inoculated control) and also inoculation with mesorhizobium ciceri (with and without bacteria) were as sub-plots. Seeds of chickpea cultivar ILC 482 were planted in pots containing 15 kg sandy loam soil, After 95 days, plants were harvested and some of their growth indices were measured.Results: Results indicated that the effect of moisture on number of pods per plant, number of seeds per pod, shoot and root dry weight, plant height and root volume was significant. Mesorhizobiuminoculation significantly increased all of measured parameters (except flowering time) compared with the control, while mycorrhizal inoculation was significant on plant height. The interactive effects of water and mycorrhiza and also interactive effects of water, mycorrhiza and Mesorhizobium were significant on shoot dry weight only. Chickpea shoot dry weight decreased by 47.3% and 78.5% with decreasing soil moisture from field capacity to -5 bar and - 10bar respectively, while this decrease was by 40.5% and 71.2% inG. mosseae inoculation and by 37.7% and 72.5% inG. intraradices. In case of co-inoculation of two fungi, the decrease was by 78% at -10 bar, while at -5 bar tension, shoot dry weight not only did not decrease but also increased by 22%.Conclusion: Water stress considerably decreased the number of grain per plant. Mycorrhizalfungi inoculation relieved the reduction of dry weight due to water stress and actually helped plant. Fungi beneficial effect was better in the occurence of Mesorhizobium bacteria.

Background and Objectives: Irregular land use, land degradation and increasing yield per surface area unit supplicate to be inevitable optimal land utilization. Therefore, land evaluation, planning and management are necessary to achieve a sustainable development. Following this trend, MicroLEIS (Mediterranean Land Evaluation Information System) has evolved towards an agro-ecological decision support system. The goal of this study is land planning of some parts of Khajeh region.Materials and Methods: Soil morphological and analytical data were carried out for 26 land units. Then, bioclimatic deficiency, land capability and qualitative land suitability (For Sunflower, Maize and Melon) and forest or pastures were determined using MicroLESE models.Results: Based on Terraza model, rainfed cultivation is possible with less than 20% yield reduction for all crops except maize. Based on Cervatana model 9 land units (27.8 of total area) were categorized as S3 and N and 17 land units (72.2 of total area) were classified as S1 and S2.Land suitability evaluation of susceptible lands using Almagra model revealed that 18.1, 39.9 and 13.2 can take place in moderately suitable (S3), suitable (S2) and excellent (S1) respectively.Results of applying Sierra model, were obtained any forest species communities suitable for the study area. Therefore, within the framework of the land evaluation decision support system MicroLEIS, a data processing tool (Sierra2 model) was developed for evaluating the relative suitability species and 5 species is suitable for this land unit.Conclusion: MicroLEIS DSS appears to be useful in semi-arid regions, for example Khajeh, to formulate sustainable agricultural systems.

Background and Objectives: Environmental issue is one of the most important components of global macro policies, therefore, one of the main prerequisite of many activities in macro level is compatibility with environment. Environmental pollution is one of the most significant challenges that is faced by human society in 21st century. Agriculture sector compared to the other sectors of economy is more closely related with environment. Environment from one hand provide main factors such as soil and water which are needed for production of agricultural crops and on the other hand its affected by pollution resulted from production activities of agricultural sector especially pollution due to over consumption of chemical fertilizers and pesticides. In recent decades consumption of chemical fertilizers have had undesired effects and outcomes such as soil and water pollution which in turn resulted in health condition of human beings as well as rest of living creatures. The aim of this study is to investigate the effect of reducing the consumption of fertilizer and water to cultivated area of crops in Behshahr County.Materials and Methods: In this study with application of Positive Mathematical Programing (PMP) effects of policies reduction of water and fertilizers consumption on cropping pattern of agricultural products of agronomy sub sector of Behshahr County of Mazandaran Province was investigated. Required data were gathered through Jahad-e-Agriculture organization and regional water organization of study area and statistical center of Iran. Information regarding cost of production and farmers income were gathered through direct interviews with farmers of Behshahar County. In this research simple random sampling methods was used thus 133 farmers were interviewed.Results: The results show that implementing the policy of reduction the amount of fertilizer used by 49 percent, will reduce cultivated area of all crops and the most part of reduction will occurs in the area under rainfed rapeseed. If the policy of fertilizer reduction of 56 percent comparing to current level of consumption of fertilizer is implemented the area under cultivation of agricultural crops will reduce and most of this reduction will ensue in the area under the cultivation of rainfed wheat. Under the policy of reducing the amount of irrigation water by 13.93 percent, cultivated area of all irrigated crops decrease and rainfed crops (Rainfed wheat, Rainfed barley and Rainfed rapeseed) will not change.Conclusion: As it is obvious from the results, reduction in the consumption of chemical fertilizers has more effects on rainfed crops, it is suggested that reduction in level of fertilizer consumption in the areas which contain rainfed crops is performed cautiously. Thus, noting to the results of this research work it is suggested that in order to prevent the reduction in the area under the cultivation of irrigated crops it is required to improve irrigation efficiency by usage of under pressure irrigation so that production of irrigated agricultural crops would not be effected by reduction of consumption of irrigation water.

Background and Objectives: Maintaining soil productivity is one of the key factors in sustainable agriculture. Erosion often causes changes in soil physical, chemical and biological properties as well as reducing soil productivity over a long-term period of time. Therefore, determining soil erosion tolerance is necessary for sustainable agriculture production. There are several methods to evaluate the effects of erosion on crop yield and soil productivity such as productivity index, which is one of the most common methods. PI model is a relatively simple model that needs limited variables. That is why it is widely used in areas where there are limited data.Materials and Methods: In this study, the long-term effects of erosion on soil productivity in the typical Kohin watershed were evaluated. For this purpose, four profiles were drilled and described in the area. Modified productivity model was used to evaluate soil productivity changes, resulting in long term effects of erosion. Productivity reduction rate of 5% over 100 years was considered as the threshold to determine soil loss tolerance, based on soil and climate conditions of the area. The average annual erosion rate was estimated using the cesium-137 method.Results: The results showed that the average annual erosion rate of Kohin watershed was 44 tons per hectare per year based on cesium-137 activity method in the last 50 years, equivalent to a loss of 7.3 mm of topsoil every year. Therefore, soil productivity reduces about 0.58 percent annually due to current erosion. Considering productivity reduction rate of 5% over 100 year as an acceptable threshold, soil loss tolerance of Kohin soil series was calculated about 4.7 tons per hectare per year.Conclusion: In order to sustain soil productivity and agricultural production up to 100 years, it is necessary to reduce the amount of erosion around 90 percent. Considering the sediment delivery ratio of 0.25, the average annual sediment load was obtained about 1.1 tons per hectare per year, which is acceptable in terms of environment. Both organic matter content and available water content had the highest impact on soil productivity index. Therefore, it is recommended to take appropriate management measures toward increasing soil organic matter in order to enhance soil productivity of Kohin series.