فهرست مطالب مجید فکری

Due to the lack of suitable water resources and poor soil quality (high salinity, low organic matter, and plant nutrient deficiency), the increase of arable lands in arid and semi-arid regions has faced severe challenges. The use of organic amendments is recognized as a critical strategy for plant production in such soils. Nowadays, humic acid (HA) is known as one of the eco-friendly fertilizers that not only preserves soil quality but also plays a significant role in increasing the production of high-quality agricultural yields. The present study was conducted to extract humic acid from two sources of cattle and sheep manures and compare their effect on maize growth characteristics and inorganic phosphorus (Pi) forms in a calcareous soil compared to the commercial HA.

25 kg of sheep and cattle manure were collected from the farm of Shahid Bahonar University in Kerman and composted separately under controlled conditions for three months. Humic acid was extracted from composted manure using 0.5 N NaOH (1:10 material: extractant) in a dark environment under no oxygen conditions. The extracted HA's chemical and structural features, such as pH, EC, elemental composition, and functional groups, were determined. To investigate the effect of extracted humic acid on the growth of maize and soil inorganic P forms, a completely randomized design with seven treatments, including 0.1 and 0.2% of cattle manure extracted humic acid (CM-HA), 0.1 and 0.2% of sheep manure extracted humic acid (SM-HA), and 0.1% and 0.2% levels of commercial humic acid (HA), and a control treatment was designed in four replicates. The seedlings of maize were planted in treated pots and kept for 70 days under greenhouse-controlled conditions. At harvest time, the fresh and dry weights of the shoot and roots were measured. Soil Pi fractions, including H2O-extractable P, NaHCO3-extractable P, NaOH-extractable P, and HCl-extractable P, were also determined after maize harvesting.

The results showed that commercial humic acid had the highest pH and the lowest EC compared to the extracted acids. In contrast, humic acid extracted from cattle and sheep manure was more acidic than the commercial HA. The results of FTIR indicated the presence of phenolic hydroxyl, carboxyl, and aromatic rings in the extracted and commercial humic acids. The results showed that only 0.1% of commercial humic acid had no significant effect on maize's shoot fresh and dry weight. In contrast, other extracted acids, especially SMHA, significantly increased both growth characteristics of maize. In all treatments, the overall distribution of Pi forms was HCl-P > NaHCO3-P > NaOH-P> H2O-P. The results showed that HA application at the rates of 0.1% and 0.2%, mainly extracted HA from sheep manure, increased the contribution of more labile forms of inorganic phosphorus, including H2O-P and NaHCO3-P in the soil.

Since extracted HA from sheep manure and cattle manure have better quality than commercial HA and more effectively affect the growth of maize and labile forms of Pi, these resources can be used as an alternative for HA extraction and HA-based fertilizer production. In general, 0.2% of extracted humic acid from sheep manure had a more influential role in increasing the labile P forms in the soil and the growth of maize plants compared to other treatments.

Considering the environmental problems caused by heavy metals in surface and underground water, surface adsorption can be considered as a promising alternative to reduce heavy metal ions in water resources. In this study, cadmium absorption by pistachio pulp biomass and their produced biochars at 300 and 500 0C in 1401-1402 at Shahid Bahonar University of Kerman was investigated. The properties of biomass and the produced biochars were determined. The effect of pH (2-7), contact time (5-1440 minutes) and different initial concentrations (200-10 mg L-1) on cadmium absorption was evaluated. In addition, pseudo-first-order and pseudo-second-order kinetic models as well as Freundlich and Langmuir isotherm models were evaluated. The obtained results showed that the percentage of carbon increased and the percentage of hydrogen, nitrogen and sulfur decreased with pyrolysis of pistachio pulp biomass. SEM images showed that the surface of biochar is more irregular and rough than the biomass. Also, the optimal pH was 5 and the solution reached equilibrium in 120 minutes. Adsorption of cadmium by adsorbents showed a better fit with pseudo-second-order kinetic model and Langmuir isothermal model. The maximum cadmium absorption capacity by pistachio pulp biomass, biochar 300 and biochar 500 was 40.5, 58.2 and 72.5 mg g-1, respectively. The results of this study showed that the amount of cadmium absorption increased with the increase of pyrolysis temperature and pistachio pulp biochar has a high capacity to adsorb cadmium from aqueous solution.

Extraction of humic substances from animal manures can be considered as one of the optimal management solutions for these wastes. This research aimed to identify the characteristics of humic acid from two sources of cattle and sheep manure at two levels of 100 mg and 200 mg and compare their effects with commercial humic acid on the growth of soybeans in a completely random design in greenhouse conditions. Based on the spectrophotometric ratio, E3/E5, the lowest molecular weight was related to humic acid extracted from sheep manure. The infrared spectroscopy results indicated the presence of phenolic hydroxyl, carboxyl, and aromatic ring functional groups in extracted and commercial humic acid. Phenolic OH was abundant in humic acid extracted from sheep manure, and the peak related to aromatic and aliphatic ring was removed in commercial humic acid. The results showed that humic acids extracted from sheep manure in the amount of 200 mg caused 62% increase in the fresh weight of the shoot, 48% in fresh weight of the root; and cattle manure in the amount of 200 mg increased the height of the shoot by 31%. But, the use of commercial humic acid could not influence the mentioned traits. Based on the results of this study, sheep manure can be considered a suitable source for extracting humic acid; and its application to soybean can be recommendable due to its effect on growth indicators, at the rate of 100 mg.

Pollution and accumulation of heavy metals in the soil are the most important environmental challenges that threaten the lives of plants, animals and humans. One of the effective methods to reduce the harmful effects of heavy metals in contaminated soils is the application of biochar as a soil amendment. In this study, the efficiency of almond soft husk and rice husk biochars (temperature of 500 °C) as well as their modified biochars with NaOH and HNO3 were investigated to reduce soil contamination by copper. The experiment was performed in a factorial experiment in a completely randomized design with three replications. For this purpose, two biochar treatments of almond soft husk and rice husk (unmodified and modified with NaOH and HNO3) were used in two levels (without biochar as a control and 4% by weight). Copper was added in the soil of each pots in three levels (0, 50 and 200 mg kg-1) from the copper sulfate salt source (CuSO4.5H2O). In this regard, different kinetics desorption models of copper were evaluated. Copper concentrations in different time periods (from 30 minutes to 48 hours) were determined using EDTA method in the samples. The results showed that the application of modified biochars at different times caused a significant reduction in copper desorption compared to the control treatment. There was a statistically significant difference between almond soft husk and rice husk and also between different Modified biochar at 5% level. Modified rice husk is more effective than almond soft husk. Sodium hydroxide-modified rice husk biochar reduced copper by 21% and 37%, respectively, compared to almond soft husk modified biochar at 50 and 200 mg kg-1 in 480 minutes, respectively. The power function was introduced as the best Copper desorption kinetics equations due to its high values coefficient of determination (R2) and low values standard error of estimation (SE).

providing the food needed by the world's ever growing population has led to changes in cultivated areas, water resources, and the overuse of chemical fertilizers and consequent environmental pollution. Providing essential nutrients to the plant is one of the most important factors related to the optimum production of agricultural crops. In recent years, most of essential nutrients are provided through the natural fertility of the soil and chemical fertilizers. Today, one of the most important ways to increase soil fertility is the use of fertilizers. Consistent and excessive use of fertilizers such as nitrogen and phosphorus (in the form of ammonium salts, urea, nitrate or phosphate compounds) in recent years has caused problems in the agriculture and environment. In recent years, the efficiency of application of nitrogen, phosphate and potash fertilizers has been about 30-35, 18-20 and 35-40-40, respectively. This indicates that a large part of the fertilizer used remains in the soil or enters the aquatic ecosystems and negatively affects the natural balance and biodiversity of agricultural lands. Accordingly, to overcome these problems, it is necessary to use solutions such as better water and fertilizer management, change in the structure of fertilizers and the use of new technologies. One of the effective methods to overcome the problems of low efficiency of chemical fertilizers is to develop the controlled release fertilizers. Slow-release fertilizers can be a good way to overcome the problems expressed by common chemical fertilizers. Release control fertilizers are usually prepared using the coating method and reducing the solubility of water-soluble fertilizers by creating a physical barrier. The biggest problem with slow release fertilizers is their high production cost. Therefore, it is necessary that the fertilizers covering chemical fertilizers be economical and compatible with the environment and have desirable coating properties. Nanocomposites are among the polymer coatings that have received much attention in recent research. Among the many materials used to form nanocomposites, polysaccharides such as cellulose, starch for economic reasons, biocompatibility, non-toxic and biodegradable are widely used compared to synthetic polymers. Despite many studies in the field of fertilizer production, the use of slow release fertilizers as a source of required nutrients and also the use of hydrophilic and hydrophobic polymers such as pure cellulose compounds with conventional fertilizers have not been studied. The need for this research is to use cellulose from agricultural waste in slow release of chemical fertilizers in order to increase the efficiency of fertilizers, prevent its overuse in agriculture, and also waste agricultural waste around orchards. In this study, cellulose compounds were extracted from paper, palm and pistachio branch and these cellulose compounds were then used to slow the release of urea fertilizers.

First, the sufficient amounts of pruned wastes from branch of palm, pistachio, and paper waste, were collected from agricultural regions in Kerman Province; then they were transferred to the laboratory of Kerman Agricultural Research Center. After washing and drying, the samples were ground. In the next step, 10 g of each of the air-dried cellulosic sources was passed through a 60-mesh sieve in an Erlenmeyer flask with 200 ml of 1% NaOH solution for 1 h. Then, it was entirely washed with distilled water and the resulting contents in the Erlenmeyer flask were re-boiled along with a mixture containing 300 ml of 80% acetic acid plus 30 ml of 67% nitric acid for 30 min at 120°C. At the end of the reaction time and partial cooling of the mixture, the cold distilled water was added to the reaction mixture and the resulting cellulose pastes were then washed thoroughly with distilled water until reaching the neutral pH. At the end, the samples were air-dried. Finally, the cellulose samples were washed with distilled water and air dried. In the second stage, slow release of urea fertilizer with cellulose from palm wastes in a ratio of 1 to 2 (fertilizer to cellulose) was made and they were made in the form of small tablets. Nitrogen release kinetics from these fertilizers in soil up to 90 days were measured and kinetic equations were also investigated.

After cellulose extraction of wastes, FTIR device was used to identify the extracted celluloses and compare them with Sigma Aldrich pure cellulose. The peaks obtained from the FTIR apparatus were similar to the pure cellulose peaks. The yield of extracted cellulose in the form of paper waste was 70%> palm branch 33%> branch of pistachio 28%. In the second stage, the extracted cellulose was used to cover urea fertilizer in a ratio of 1 to 2 (urea fertilizer to cellulose) and the desired fertilizer was made in the form of small tablets with diameter of 0.5 cm and height of 2 cm. The SEM scanning electron microscope was used to study the structure of the manure. Microscopic images showed that the urea fertilizer placed as white spherical particles around the cellulose rod particles, indicating that the urea fertilizer particles adhered to the cellulose particles without any adhesive. The FTIR diagram of the fertilizer showed that the shift of the diagram upwards at the common wavelengths in urea and pure cellulose and a strong physical bond is established between them. Nitrogen release kinetics for all treatments that were less than pure urea fertilizer and significant differences observed between treatments and pistachio branch cellulose caused a slower release of urea fertilizer. The kinetic equation of the power function was selected as the best model for fitting the kinetic data. The studied wastes in this study have a high potential for producing pure cellulose to slow the release of urea fertilizer.

Soil spectroscopy has overcome many limitations of conventional soil analysis methods due to its rapid, accurate, cost-effective, and non-destructive nature. This study was aimed to investigate the capability of soil spectral data in estimating some key soil properties and comparing different spectral preprocessing methods in determining the performance of the partial least squares regression (PLSR) model. For this purpose, 100 soil surface samples were collected from the study area which was located between Neyriz and Estahban regions in the east of Fars Province. The samples were analyzed for organic carbon (OC), electrical conductivity (EC), calcium carbonate equivalent (CaCO3) and gypsum using standard laboratory methods. Then, the spectral reflectance of the soil samples was recorded in the range of 350-2500 nm and various spectral pre-processing methods were applied to the data. Afterwards, the soil properties were estimated using PLSR. The results indicated the desirable capability of PLSR method in estimating the amount of gypsum (RPD >2, R2 = 0.81, RMSE = 3.87) and its acceptable ability for OC, EC and CaCO3 (2< RPD < 1.4). Also, the best modeling systems for OC, gypsum and EC were obtained as the first derivative with Savitzky-Golay smoothing method (FD-SG), the standard normal variate method (SNV), and the second derivative with SG smoothing method (SD-SG), respectively. Besides, non-preprocessing data of soil CaCO3 provided better estimations than various pre-processing methods. Overall, the results revealed that the visible spectrum range provided the best performance for estimating of OC and EC, and the NIR range for CaCO3 and gypsum.

The increase in population has led to the production of large amounts of agricultural wastes that pollutes the environment. Today, the use of agricultural wastes to extract cellulose and nano-cellulose is increasing. In this study, cellulose and nanocrystalline cellulose were extracted from three types of palm waste, including fibers, leaves and palm clusters and used to identify cellulose and compare it with pure cellulose SigmaAldrich from devices using FTIR, TGA and XRD. Cellulose extraction yield was measured at 25% in palm fibers, 20% in green leaves and 33% in clusters. The FTIR and XRD spectra of isolated cellulose was similar to pure cellulose and the degree of crystallization was in order of leaf > fibers > clusters. The loss of weight for all cellulose samples in TGA charts at 350 oC was similar to that of pure cellulose and the nanoparticle length range of these cellulose was determined by the FE-SEM electron microscope 20 to 36 nanometers.

Fluoride is widely used in industries and release to the environment via their effluents. One method of fluoride removal is adsorption using inexpensive adsorbents. The purpose of this sturdy was to compare the efficiency of pistachio pulp biochar in fluoride removal from water.In this study, pistachio pulp biochar was produced through pyrolysis at 600 °C for 3 hours with a heating rate of 25 °C min-1. To determine the adsorption isotherms, 20 mL of fluoride solution with different concentrations (zero, 3, 6 and 9 mg L-1) of NaF salt was added to 0.5 g biochar and then the samples were shaken for 24 hours and finally the adsorption data were fitted to Langmuir, Freundlich and Temkin isotherm models. In order to investigate the effect of time on fluoride adsorption, 20 ml of fluoride solution with initial concentrations of  3, 6 and 9 mg L-1 was added to 0.5 g biochar and samples were shaken for different times (15, 30 , 45, 60, 90,75, 105, 120, 135, 165, 180, 195, 210, 225 and 240 minutes). Then, the concentration of Fluoride was measured. The results showed with increasing the retention time, the percentage of fluoride adsorption by biochar increased and after 240 minutes for concentrations of 3, 6 and 9 mg L-1 were obtained 70.89, 63.05 and 54.66, respectively. The pseudo-first-order and pseudo-second-order models were introduced as the best kinetic models of fluoride adsorption compared to other models. The results of fitting data to the Langmuir, Freundlich and Temkin isotherm models showed that Langmuir model provides a better description of the fluoride adsorption process by biochar. The maximum fluoride adsorption (306 mg kg-1) was obtained by biochar from the Langmuir model.

Today, soil pollution is an important environmental issue that should be taken into account. Industrial activities cause pollution and accumulation of heavy metals in the soil. Soil pollution significantly reduces the quality of the environment and threatens human health. Heavy metals are one of the most important pollutants in the environment, which has received a lot of attention in recent decades. Heavy metal pollution is a serious problem in developing countries and urban areas. Among heavy metals, lead is found in large amounts in the Earth's crust, which has several effects on human health and the environment. Lead is an essential element for the plant and one of the most important pollutants, which is toxic even at very low concentrations. Its presence in the culture medium has a negative effect on germination rate, water status in the plant, dry root weight and aerial part of the plant, photosynthesis, absorption of nutrients and enzymatic activity. Much research has been done to use alternative and modern methods to clean the environment of heavy elements. One way to stabilize heavy metals in the soil is to use biochar. Due to its cation exchange capacity and high specific surface area, biochar is able to reduce the pollution caused by organic pollutants and heavy metals, stabilize heavy metals and improve the condition of plants and soil in terms of pollution. The aim of this study was to investigate the effect of modified biochars rice husk and almond soft husk on lead desorption kinetics in contaminated calcareous soil. To conduct this research, a sufficient amount of soil from a depth of zero to 30 cm was collected from the farm of Shahid Bahonar Agricultural College in Kerman. Physical and chemical properties of the studied soil were measured after air drying and passing through a 2 mm sieve. To prepare the biochars (rice husk and almond soft husk), the residues, after collection, were air-dried and ground and then packaged in aluminum foil to limit the oxygenation process. They were then placed in an oven at 500 0C for four hours to produce a charcoal called biochar. Also, to prepare the modified biochar (NaOH and HNO3), one gram of biochar was added to 100 ml of distilled water and then 10 ml of concentrated acid (or 10 g of alkali) was added to it. Stirring at 60 0C for 24 hours. Finally, it was filtered using a centrifuge and washed several times with distilled water to neutralize the pH. The produced powder was dried at 70 0C for 24 hours. The lead desorption kinetics experiment was studied at several times (5, 15, 30, 60, 120, 240, 480, 960, 1440 and 2880 minutes) in two levels of biochar (0 and 4 wt %) and three levels of lead (0, 300 and 600 mg kg-1), which were incubated for 5 months under field moisture in a greenhouse. The kinetics results showed that the desorption of lead has the same pattern in all the time studied. Early rapid desorption occurred in the early desorption times (initial 30 minutes) followed by low-velocity desorption (8 hours) and finally, equilibrium was observed in the treated and control samples. The significant difference between the amount of lead released from the treated soils and control indicated a positive effect of both used engineered biochars on reducing lead desorption. The highest amount of lead desorption was observed in soil without biochar, while the lowest desorption rate occurred in treatments of rice husk and almond soft husk modified by sodium hydroxide. The application of modified biochar rice husk highly reduced lead desorption, compared to modified biochar almond soft husk. According to the results, the modified biochar with sodium hydroxide caused a significant reduction in lead desorption compared to other treatments, and this reduction was more in biochar rice husk than the almond soft husk one. It can be stated that rice husk biochar has been more successful than almond soft husk biochar due to its more porous structure and cation exchange capacity. Among the equations used for lead desorption estimation, the two-constant rate equation was selected as the best model for data fit due to high explanatory coefficient (R2) and low standard error (SE). According to the above, the use of biochar can be recommended as a modifier in lead contaminated soils.

Cadmium (Cd) is one of the most common and dangerous environmental contaminants. The effect of soft almond husk compost and its biochar was studied in the kinetic of cadmium desorption on a calcareous soil in the field of Shahid Bahonar Agricultural College, Kerman. For this purpose, compost and biochar of soft almond husk were used in three Levels (0, 2 and 4 % w/w) and were added to calcareous soil contaminated with three levels of cadmium (0, 40 and 80 mg kg-1). Sampling from treated soils was carried out 45 and 90 days after the contamination of soils with cadmium. Samples from treated soils were extracted by EDTA in 5 to 2880 minutes in different periods of time and the concentrations of cadmium were measured. The results showed that the application of compost and soft almond husk biochar reduced the desorption of cadmium compared to the control. The lowest amount of cadmium desorption occurred at level 4% w/w biochar and compost, while biochar had the highest reduction amount in the desorption of cadmium compared to the soft almond husk compost. Based on the experimental results, the cadmium desorption was highest in all treatments at initial times and decreased over the time. In other words, 50% of cadmium desorption occurred in the first 2 hours. In 90-day sampling compared to 45-day one, cadmium desorption from soil showed the highest decrease. Based on the determination of coefficient and standard error, the power function equation is considered as the best predictor of the cadmium release kinetics trend in the studied soil.

The availability of the applied phosphorus (P) is controlled by sorption-desorption reactions in soil. Since the sorption-desorption reactions are affected by physical and chemical properties of the soil, the presence of organic matter (OM) and carbonates can also effect on the P sorption capacity in soil. The purpose of this study was to investigate the effects of OM and carbonates on phosphorus sorption isotherms in some calcareous soils of Kerman province.

Six surface soil composite samples (0-30) were collected from Kerman Province located in southeast of Iran. The soils with a wide range of OM and calcium carbonate were selected for sampling. Samples were air dried and passed through a sieve of 2 mm. Physicochemical properties of the soil samples were determined according to the Soil Survey Laboratory Manual. Thereafter, the soil samples were divided into three parts. One portion was used for treatment with sodium hypochlorite to remove organic matter. The second part was treated with sodium acetate buffer (pH = 5) to remove carbonates. The third was used as a control without any treatment. Batch experiments were carried out to determinthe P-sorption isotherms in soil. The sorption behavior of P was studied by Langmuir and Freundlich isotherm models. All experiments were conducted in three replications.

The results showed that organic matter and equivalent calcium carbonate, removed from the studied soils with an average efficiency of 86.7% and 84.9%, respectively. Although the isotherms data showed that both Langmuir and Freundlich equations fits to data,Langmuir equation with higher mean of correlation coefficient (R2=0.982) and lower standard error (0.022) showed the best fit to P-sorption data for all soil samples (with and without treatment). Removal of organic matter by sodium hypochlorite increased the phosphorus adsorption capacity in the studied soils. After removal of soil organic matter, an increase in phosphorus adsorption capacity in the studied soils. With respect to control, removing the organic matter increased the adsorption capacity parameters (qmax and kf) about 37 to 104 mg.kg-1 and 11 to 23 L.kg-1, respectively. These results indicate that Fe- and Al-oxides and other available adsorption sites on the mineral surfaces are coated by organic matter and are activated after removal of OM. Removal of carbonates from the soil significantly reduced the P-sorption capacity. qmax and kf were decreased by 17% and 32%, respectively, compared to untreated soils. It is, therefore suggested that available P adsorbing surfaces decreases by removing carbonates from the soil.Constants related with bonding energy increased by 17.03% and decreased by 28.78% by removal of OM and calcium carbonate, respectively. The P maximum buffering capacity is an important indicator for assessing phosphorus stabilization capacity in soil. The greater P buffering capacity, the fewer ability of phosphorus replacement to soil solution. After removal of carbonates, this parameter decreased by an average of 42.5%. The results suggested that carbonates is an important factor in availability of phosphorus in soil. The required phosphorus standard increased by 14.43% by removing OM in the studied soils. However, the removal of carbonates reduced the need of soil for phosphorus by 40.5%.

In this study was investigated the effect of removing organic matter and carbonates on phosphorus sorption isotherms in some calcareous soils of Kerman province. The results of this study showed that P sorption capacity is affected by the amount of carbonates and organic matter. Removal of organic matter from the soil increased the sorption capacity of phosphorus due to Fe- and Al-oxides. Other available adsorption sites on the mineral surface which are coated by the organic matter are active. Carbonates is known as an active site for maintaining phosphorus in the soil and its removal from soils reduces the phosphorus adsorption capacity. Applying/Preserving organic matters to/in soil can increases the efficiency of phosphate fertilizer application and improves plant nutrition. The removal of carbonates from the studied soils reduced their need for phosphorus. Therefore, as well as the addition of organic matter to soil, the removal or reduction of carbonates from agricultural soils is important for improving phosphorus utilization efficiency and plant nutrition management.

Phosphorus availability in soils is controlled by sorption/desorption reactions. These reactions are also affected by the physical and chemical properties of the soil. In this research, effects of organic carbon, active calcium carbonate and clay on the phosphorus sorption behavior of calcareous soils were studied along Negar-Lalezar and Baft Orzouyeh transects in Kerman Province, Iran. The phosphorus sorption in soil was determined using batch experiment and Langmuir, Freundlich and Van Hay isotherms. The results showed that, based on the coefficient of determination (0.978) and standard error of estimate (0.027), Langmuir model fitted well with experimental data. Maximum sorption of phosphorus (qmax) and maximum buffering capacity of P increased when the active calcium carbonate increased. Results showed that qmax increased from 655 to 1025 mg.kg-1, and the maximum buffering capacity of P increased from 114 to 243 L.kg-1 when calcium carbonate increased from 7.68% to 18.25%. However, qmax decreased from 701 to 535 mg.kg-1 and maximum buffering capacity of P decreased from 90 to 44 L.kg-1 with increasing organic carbon in the studied soils (from1.74% to 7.8%). Using the equation of Van Hay, the required standard phosphorus calculated at a concentration of 0.3 mg P.L-1 showed a significantly positive correlation with clay (r = 0.80**) and active calcium carbonate (r = 0.77**) contents, but significantly negative correlations with organic carbon (r = -0.63*) and available phosphorus (r = -0.61*). The maximum buffering capacity and the required standard phosphorus were found in the soils of Orzouyeh and Negar regions due to their highest percentage of active calcium carbonate and clay. However, in the soils of Lalezar and Baft regions, due to the presence of more organic carbon and less active calcium carbonate, the lowest standard phosphorus requirement was obtained. It could be concluded that phosphorus sorption in soils is influenced by soil properties such as clay, active calcium carbonate, and organic carbon contents.

Introduction Phosphorus (P) is an essential nutrient for all forms of life on the earth, but in excess concentrations, it can act as a serious water pollutant through eutrophication. Thus, it is very important to remove P from aqueous solutions before their release into natural water resources. Among the various P removal techniques that have been developed, the sorption process is widely accepted to be an effective water treatment technique because of low cost, ease of operation, simplicity of design, and high sorption capacity in dilute solutions. Layered double hydroxides (LDHs) are a type of two-dimensional nanostructure anionic clays with high capacities to sorption of anions. These non-silicate clays consist of positively charged brucite-like octahedral sheets which neutralize by a negatively charged interlayer containing relatively weak bonded anions and water molecules. The positive charges generated by the isomorphous substitution of trivalent cations for divalent cations are balanced by interlayer anions that can be exchanged by other anions making them good anion-exchangers with high selectivity. LDHs have been widely used as environmental sorbents because of their high charge density, large interlayer areas, good thermal stability, and high anion exchange capacities of the interlayer anions. The aim of the present study was to synthesize a Mg-Fe LDH as a sorbent for P removal from aqueous solution. Materials and Methods The Mg-Fe LDH was synthesized using the co-precipitation method. In brief, a mixture solution containing 0.03 mol MgCl2. 6H2O, and 0.01 mol FeCl3. 6H2O was added dropwise into a flask containing 100 ml of 1 M NaOH solution under vigorous stirring at pH=10. The obtained slurry was filtered and washed repeatedly with DW until the filtrate pH reached neutral. Mg-Fe LDH particles were then obtained by drying the filtrate at 70 °C in an oven overnight. The crystallinity of the sample was studied using X-ray diffraction (XRD) analysis. In order to investigate the performance of the synthesized LDH as a P sorbent, batch experiments were carried out in polyethylene centrifuge tubes. The suspensions were shaken for 24 hours at 250 rpm, and the supernatant was then separated by centrifugation at 4000 rpm for 10 minutes and were filtered by Whatman ashless grade 42 filtration papers. Equilibrium P concentration was determined according to the ascorbic acid method using UV-vis spectrophotometer at the wavelength of 880 nm. The effects of pH, initial P concentration, and contact time on P sorption were investigated in the ranges of 2-10, 0-300 mg/L and 0-1440 min, respectively. Results and Discussion The XRD pattern of the LDH sample showed typical structure of hydrotalcite-like compounds with sharp and reflection peaks corresponding to the (003), (006), (012), (015), and (110) crystal planes which are characteristic planes of hydrotalcite-like compounds. The efficiency of LDH to remove P decreased with the increasing of initial P concentration and the maximum removal efficiency of LDH occurred in the range of 5-20 mg/L of initial P concentration. With increasing of initial P concentration from 20 to 300 mg/L, the P removal efficiency of LDH decreased from 98.7 to 24.6 %. The P removal efficiency was increased with time and reached equilibrium at 60 min. The P removal rate of LDH in this time was about 66 % and no significant decrease in residual P concentration was observed after 60 min. The sorption of P on LDH was highly pH dependent, and the maximum P removal was found at pH of 4. The sorption kinetic and isotherm data were well described by pseudo-second-order and Langmuir equations, respectively. According to the Langmuir equation, the maximum P sorption capacity (Qmax) of LDH was obtained as 13.96 mg/g. Conclusion It was found from the results of this study that the mechanisms involved in the P sorption onto LDH included electrostatic attraction, ligand exchange, and surface complex formation. In addition, the results suggested that the synthesized Mg-Fe LDH can be potentially used as an effective sorbent for the removal of P from aqueous solutions. Further research is needed on the regeneration of the LDH after P sorption and the evaluation of desorption behavior of P from LDH under different conditions.

In this research, the short-term beneficial effect of using different pistachio wastes biochars on improving some fertility properties of a loam soil was investigated. Therefore, the effects of two factors 1) types of amendments added to the soil, including biochars of pistachio mildew (PM), pistachio hard skin (PHS) and wood of 20-year pistachio trees (W) papered at 600o C (with amount of %5 by wt), and 2) time of incubation (1, 2, 3, 4, 5 months), were investigated on pH, electrical conductivity, soluble potassium, nitrate and availability of iron, copper, manganese and zinc. This experiment was performed as factorial based on the completely randomized design with three replicates. The results of this study showed that the application of biochars and different incubation times does not have a significant effect on soil pH. But, the threated soils at all incubation times showed a significant increase in electrical conductivity and organic carbon as compared to the control treatment. Addition of biochars and incubation time increased significantly potassium content of the soil solution, so that the treated soils had an increase of approximately two times solution potassium as compared to the control. Application of biochars to the soil caused an increase in nitrate retention and a decrease in nitrate solution as compared to the control sample. Biochars application led to a significant increase in iron content and irregular increase in zinc, copper and manganese. The availability of these elements in the soil decreased by time due to reduction of biochar decomposition and transformation of those elements from available into less available forms.

Introduction: Under natural conditions, intensive and erosive storms commonly associate with high-speed winds. In fact, wind velocity affects water erosion rate through enforcing falling drops and enhancing rainfall erosivity. Therefore, knowledge of interaction between wind and rain as erosive agents on interrill erosion is of prime importance. However, no comprehensive study has been done on this topic under controlled laboratory conditions. This study was conducted to investigate interrill erosion affected by different rain intensities and wind velocities on several soils with different aggregate size distributions using the Simultaneous Wind-Rainfall-Runoff Simulator (SWRRS). For this purpose, a multisystem was constructed for the first time in Iran to investigate the simultaneous effects of wind and rain erosivity agents on soil erosion under laboratory conditions. Materials and Methods: The simulator was calibrated in two cases. First, the intensity and uniformity of the simulated rains were assessed for each nozzle, separately. Second, the calibration procedure was performed for different combinations of the selected nozzles to achieve the best performance. For each case, different water pressures were generated to introduce several water discharges and make initial raindrop velocities. Afterwards, the interrill erosion experiment was done using four constant wind speeds including 0, 6, 9 and 12 m s-1at the height of 40 cm which were applied in combination with three rain intensities of 30, 50 and 75 mm h-1 on three soil samples with different aggregate size distributions (D2mm, D4.75mm and D8mm). Each treatment was conducted at three replicates under laboratory controlled conditions. By using different wind speeds, rain intensities and soil aggregate sizes, interrill erosion rate was measured under steady state conditions. Results and Discussion: Results showed that wind velocity has a significant effect on interrill erosion rate and the interaction between wind and rain on interrill erosion was significant, as well. Although, there was no significant difference between the erosion rate at wind velocity of 0 and 6 m s-1, the wind velocity of 9 and 12 m s-1 showed significant difference with and higher erosion rates than the velocity of 6 m s-1. The mean erosion rate at wind velocities of 0, 6, 9, 12 m s-1 was 0.43 × 10-4, 0.54 × 10-4, 0.97 × 10-4 and 1.46 × 10-4 kg m-2 s-1, respectively. With increasing rain intensity from 30 to 75 mm h-1, the erosion rate increased from 0.52 × 10-4 to 1.16 × 10-4 kg m-2 s-1. On average, the erosion rate of the soil containing larges aggregates i.e. D8mm (0.73 × 10-4 kg m-2 s-1) was less than that with the finest aggregates i.e. D2mm (0.99 × 10-4 kg m-2 s-1). The findings of this study highlighted the importance and necessity of more attention to wind speed particularly those velocities faster than a threshold velocity in the study of interrill erosion. Conclusion: In arid and semi-arid regions such as most parts of Iran, rainstorms are usually accompanied by strong winds. Despite the undeniable influence of wind on the erosive power of rain, a host of research has investigated water and wind erosion processes, separately. Therefore, this study was done to investigate the simultaneous effect of wind velocity and rain intensity on interrill erosion rate in three soil samples. The results indicated that wind velocity has a remarkable influence on interrill erosion rate due to wind-driven rain. Wind velocities faster than 6 m s-1 increased interrill soil erosion rate, particularly those combined with higher rain intensities. This is due to an increase in the velocity of falling raindrops on the soil surface which results in greater kinetic energy. Also, the findings showed that the soil containing coarser aggregates due to greater random roughness exhibited less sensitivity and interrill erosion rates as compared with the soil having finer aggregates, especially at faster wind velocities. The rate of interrill erosion in soil D2mm was 1.35 times higher than soil D8mm indicating the importance of random roughness. In addition, there was no significant difference between the measured erosion rates at wind speeds of 0 and 6 m s-1, in all cases. However, with increasing wind speed from 6 to 9 and also to 12 m s-1, significant increases in soil erosion rates were observed. Accordingly, a threshold wind velocity can be considered in wind-driven interrill erosion. The findings of the present study can be applied for better understanding and modeling of water and wind erosion mechanisms and dominant processes.

Due to low plant cover in arid and semi-arid regions, surface gravel cover (SGC) plays an important role in soil erosion control. The aim of this study is to investigate the effect of SGC and slope gradient on splash as well as interrill erosion in two contrasting soils. For this purpose, a constant rain was simulated on two soils namely sandy and cropland with different aggregate size distributions at four slope gradients including 0.5, 2, 5 and 10 % and five levels of SGC including 0, 5, 10, 20 and 40 % each at three replicates. Through producing a rain intensity of 35 mm/h for 35 min duration on a 0.35 m by 0.35 m test area, both splash (downward, upward and the total splashed material) and interrill erosion rates were measured. Result showed that with increasing SGC in both soils, the downward, upward and the total average splash increased, significantly. However, the downward splash rate was higher than the upward splash rate. With increasing SGC from 0% (control) to 5, 10, 20 and 40 %, the downward splash rate decreased for the sandy soil by 12.9%, 25.3%, 35.7% and 47.7%, and for the cropland soil by 13.9%, 25.4%, 37.0% and 49.4%, respectively. Regarding the interrill erosion rate, the corresponding reduction percentages for the sandy soil were 13.5%, 26.4%, 33.3% and 46.4% and for the cropland soil were 12.9%, 30.7%, 37.3% and 45.9%, respectively. Moreover, nonlinear increases in the interrill and splash erosion rates were found at steeper slopes. Due to lower cohesion and greater detachability of sandy soil, it exhibited higher erosion rates than those for the cropland soil. The findings of this study revealed that in the presence of SGC, both splash and interrill erosion rates will reduce, significantly.

Potassium is one of the macro nutrients, which plays a major role in the growth and development of plants. One of the factors affecting the amount of soluble and exchangeable potassium is the leaching. Study the movement of potassium in agricultural soils and reduce leaching of recommended fertilizer to subsurface soil and out of the root zone is essential. The aim of this study was to evaluate the depth distribution and potassium exchange by salts of calcium and sodium in different water regimes.
Effects of calcium and sodium salts on the depth distribution of soluble and exchangeable potassium in a calcareous soil were studied under the influence of different moisture regimes. The experimental design was a factorial with three replications. Treatments were four levels of salt (calcium chloride, calcium sulfate and sodium chloride, each 10 meq per kg of soil and one without salt or control), three levels of the moisture regimen of soil (50%, 75% and 100% of the water holding capacity in the soil), and three depths of soil columns (5, 10 and 20 cm). The concentrations of soluble and exchangeable potassium were measured in the treated soils.
The results showed that the concentration of exchangeable and soluble potassium in the soil profile depends on the moisture regime's treatment. The maximum and minimum of the soluble or exchangeable potassium of soil was found in the moisture regime of 50% and 100%, respectively, and these value increased with increasing soil depth. The ratio of exchangeable potassium to soluble was increased with increasing the soil moisture. The salts of calcium chloride> sodium chloride> calcium sulfate, respectively, had most effects in the soluble and exchangeable potassium soil and also increased their ratio in the soil profile. The higher levels of the soil water increased the movement of potassium in the soil profile. Probably, the ionic strength and charge of cations of solution salts applied increase the concentrations of soluble and exchangeable potassium in the soil. The calcium ions cause soil particles to be collected and the result is an increase in soil permeability. It is another reason that more immigration potassium ions in the presence of calcium.
High leaching, especially in saline soils not only the leaching of potassium and out of reach of the element for plants but also pollute groundwater resources and this would be considered a serious threat to the environment. In the end, it can be stated that the correct planning and management of resources for the proper use of potassium fertilizers, accuracy and attention to quality irrigation water consumption affect potassium leaching loss.

Boron is one of the seven essential microelements for the natural growth of plants. The toxicity of this element occurs in arid and semi-arid regions, which is because of its high level in soils and the irrigation water of mentioned regions. The aim of this study was to evaluate the effect of nitrogen application on boron toxicity tolerance in pistachio, Badami-Zarand variety. The effects of three nitrogen levels (0, 250, and 350 mg/kg of soil) on the reduction of toxicity due to the three levels of boron (0, 15, and 30 mg/kg of soil) were examined in Badami-Zarandi variety of pistachio under greenhouse conditions. After 7 months from sowing the seeds, pistachio seedlings were harvested and desired traits were measured. The results showed that by increasing boron application level, boron concentration in the shoot and root of seedlings increased whereas their dry weight decreased. Using of nitrogen reduced the negative effects of boron on the dry weight and led to increase dry weight and decrease boron concentration in the shoot and root of pistachio, Badami variety. Nitrogen application at the levels of 250 and 350 mg N per kg of soil reduced boron uptake in shoots by reinforcing plant vegetative system and increasing chlorophyll content by 13.5% and 30.2%, respectively and finally led to diluted boron concentration in the plant (dilution effect) and reduced the effects of boron toxicity. Hence, optimized nitrogen application is suggested as one of the management methods in controlling Boron toxicity under these conditions.
A factorial experiment based on randomized complete block design with four replications was carried out. Soil sampling was done in 0-30 cm depth in a zeekzack way from a pistachio garden that located in mahmoodiye area in Rafsanjan. The soil sample was air-dried and passed through a 2mm sieve. The soil chemical and physical properties were measured. In this study, badami-zarand cultivar seed was used because it is one of the most important pistachio cultivars. The seeds were soaked in water for 24 hours and disinfected by benomyl fungicide. When the seeds germinated, they were planted in the pots containing 4.5 kg soil and without drainage, so nutrients balance was kept during growing period. After 7 months, the seedlings were harvested and B was measured.
The results showed that increasing the boron levels from 0 to 30 mg kg-1 led to decrease shoot dry weight from 3.72 to 2.45 gram and root DM from 2.28 to 1.50 gram. Increasing 30 mg kg-1 boron led to 2.8 times increase of shoot boron concentration. The averages of shoot boron concentration in the levels of 15 and 30 mg kg-1 boron were 87.6 and 122 mg kg-1DM, respectively. The boron toxicity level in Badami-Zarand cultivar is 8.9 mg kg-1 DM (Sepaskhahet al, 1994), so these levels were the cause of boron toxicity and boron toxicity symptoms were seen as leaf burn, often at the margins and the tips of older leaves.
The results showed that increasing nitrogen levels led to decrease shoot boron concentration and increase their weight. The results also showed a significant negative correlation between the nitrogen levels and boron uptake. Boron uptake in the shoots of seedlings about 13.5 and 30.2 percent decreased when nitrogen levels increased. Shoot dry weight decreased when boron application increased, but it increased when nitrogen was used (Koohkan and Maftoun, 2009).
The reduction of dry weight and increasing boron concentration occurred when increased boron application. The Maximum of boron uptake was seen by leaves, and boron toxicity symptoms were appeared as leaf burn especially at the tips and margins of older leaves. Since, boron is immobile in pistachio; it is absorbed by mass flow, so the accumulation of boron at older leaves is persuaded. Nitrogen reduced the bad effects of boron on dry weight and the bad effects of increasing boron concentration by the synthesis of chlorophyll, so it was more useful in shoot than root. Boron uptake was also reduced by nitrogen application. This effect of nitrogen is probably concerned to the increase of dry weight more than boron concentration (Dilution effect). On the other hand, nitrogen caused to increase leaf index and increase the number of seedling leaves. The injured leaves due to boron toxicity were restored, because of high leaf chlorophyll. It is suggested that this study will be done under field conditions for fertilizer application recommendations and to be used for creation of tolerant cultivars of pistachio.

To investigate the effects of phosphorus (P) and pistachio waste (raw and dry) on growth and chemical composition of pistachio (Pistacia vera L. cv. Badami Zarand) seedlings, a factorial experiment in a completely randomized design with four replications was conducted. Treatments were three levels of P (0, 50 and 100 mg P/kg soil) and three levels of pistachio green hull (0, 3 and 6% w/w). The results showed that at the first level of P application, the 3% pistachio waste treatment increased root and shoot dry weight, number of leaves and leaf area of pistachio seedlings. While, application of 6% pistachio hull significantly decreased these parameters, as compared to the control. However, root and shoot nutrient concentrations including P, sodium, zinc, iron and copper at the first level of P were reduced by pistachio waste application. At the first level of pistachio waste, P application increased root and shoot dry weight, number of leaves and leaf area of pistachio seedlings. But, all nutrient concentrations of root and shoots, except P, were reduced by increasing P level. The best response of dry weight of roots and shoots, number of leaves and leaf area of pistachio seedlings was observed from application of 3% pistachio hulls and 50 mg P/kg of soil. In general, the results of this experiment indicated that application of 50 mg P/kg soil was more effective than 100 mg P/kg soil on growth and chemical composition of pistachio seedlings. Application of 3% pistachio green hull and 50 mg P/kg soil improved growth of pistachio seedlings.

Heavy metal pollution is one of the most serious environmental problems developing in the entire world. This study was carried out to investigate the effects of Ethylene Diamine Tetra Acetic Acid (EDTA)، Municipal Solid Waste Compost (MSWC) and different levels of Pb and Cd in soil on sunflower (Helianthus annuus L.) dry matter، concentration، contents، and uptake index of Pb and Cd. This study was performed in two separate factorial experiments with completely randomized design. Treatments consisted of three levels of Cd (0، 50، and 100 mg/kg of soil) and three levels of Pb (0،100 and 200 mg/kg of soil) with four chelates including blank، EDTA، MSWC، and combined application of MSWC and EDTA. Results showed that in the treatment with 200 mg Pb/kg of soil، combined application of MSWC and EDTA increased concentration of Pb in the shoots of plant، uptake index، and total content of Pb in the plant، respectively، 2. 36، 1. 83، and 2. 13 times، compared to the control. Results also showed that in the treatment with 100 mg Cd/kg of soil، combined application of MSWC and EDTA increased concentration of Cd in shoots of the plant، uptake index، and total content of Cd in plant، respectively، 2. 48، 2. 03، and 2. 11 times، compared to the control. In general، combined application of MSWC and EDTA caused the highest increase in concentration and content of Pb and Cd in plant compared to the control and the other chelate treatments.

Soluble potassium is the most available form of potassium for plants and it is very important for crop production. This study investigates the effect of some salts, different volumes and solutions of leaching on the soluble potassium in soil. The experiments were factorial based on completely randomized design (CRD) using four salt treatments consist of control, calcium chloride, calcium sulphate and sodium chloride; three leaching solutions (distilled water, potassium chloride and potassium sulfate); eight irrigation steps (each irrigation step equals 236 millimeter or 0.25 pore volume) and three replications, which were conducted in laboratory conditions using soil columns. At the end of experiment, the soluble potassium concentration was measured in the soil columns. The results showed that among the salt treatments, the highest amount of the soluble potassium leaching was observed for calcium chloride treatment, but its differences with sodium chloride, calcium sulphate and control were significant. Moreover among the leaching solutions, potassium chloride compared to potassium sulfate and distilled water had higher effect on decreasing soluble potassium in the soil solution. Also with increasing leaching volume, the concentration of soluble potassium significantly decreased. The findings of this research showed that the importance of salinity, leaching volume and potassium fertilizer should be regarded on the soluble potassium in order to prevent the losses of this form of potassium for plants.

This study focused on the effect of organic manures as well as potassium fertilizer on some soil properties and onion yield at the field condition. The experiments were carried out as factorial in a randomized complete block design with three replications. The treatments were poultry manure (10 t ha-1)، alfalfa residue (10 t ha-1) and control each together with two levels of potassium fertilizer as K2O (0 and 250 kg ha-1). The results showed that application of poultry manure and alfalfa residue resulted in yield increasing about 57. 7 and 40. 9 % in comparison to the control، respectively. On average، the onion yield for the potassium treatment was 7. 8 % higher than for the untreated one. The application of poultry manure and alfalfa residue increased final infiltration rate 73. 2 and 56. 1 %، respectively. Inversely، potassium fertilizer caused a significant reduction in the final infiltration rate. Moreover، application of organic manures particularly poultry manure، significant increases in saturated moisture، porosity، EC، organic carbon and available phosphorous and decrease in bulk density and pH was observed، while potassium only increased soil EC، significantly. Application of poultry manure and alfalfa residue increased soil organic carbon 129. 8 and 80. 2 % and available phosphorous 104. 8 and 51. 9 %، respectively. Among different soil properties، organic carbon showed the highest influence on yield increase.