عبدالمجید رونقی

In order to investigate the effect of salinity and cadmium (Cd) on yield, chlorophyll content and antioxidant activity of Kochia plant, a factorial experiment in a completely randomized design with three replications was conducted under greenhouse conditions. The experimental treatments included five Cd levels (0, 5, 30, 60 and 90 mg Cd kg-1 soil as cadmium sulphate) and three salinity levels (0, 2.5 and 5 g kg-1 soil as NaCl equal to electrical conductivity (EC) 0.65, 9.4, and 18 dS m-1, respectively). The results showed that mean shoot fresh and dry weight, root weight, and plant height at 5 g NaCl Kg-1, decreased significantly by 22, 24, 23, and 15 %; and at 90 mg Cd Kg-1 soil decreased by 52, 67, 45, and 41%, respectively. The greatest reduction in shoot fresh and dry weight, root dry weight and plant height observed at 5 g NaCl Kg-1 + 90 mg Cd Kg-1 levels. The highest total chlorophyll content observed at control (with no salinity and Cd) and 5 g kg-1 salinity + 5 mg Cd kg-1. With addition of NaCl, the harmful effect of Cd on chlorophyll content of the plant decreased. Salinity and Cd levels had a different effects on antioxidant activity of Koshia plant. However, at higher Cd levels (60 and 90 mg Cd kg-1), with increasing of salinity levels, no significant differences was observed in peroxidase and superoxide dismutase activity. In general, the change in the activity pattern of the plant antioxidant system, especially catalase and superoxide dismutase enzymes under high stress conditions showed that Kochia plant can withstand stress conditions via activating its antioxidant system.

Salinity is an environmental problem in the world, especially in arid and semi-arid regions. High amounts of salts like sodium chloride (NaCl) in the soils and water have destructive effects on yield of plants. The harmful effects of salinity on plant growth are related to the low osmotic potential of the soil solution (water stress), the nutritional imbalance, the specific ion effect (salt stress), or the combination of these factors. The relationship between salinity and plant mineral nutrition is complicated. Under salinity stress, occurs the sodium and chlorine accumulation, resulting in ionic imbalance and the deficiency symptoms of nutrients in plants. The sodium (Na+) competes with the uptake of potassium (K+), calcium (Ca2+) and magnesium (Mg2+) by plant, and the chlorine (Cl-) with the uptake of nitrates (NO3-), phosphates (PO43-) and sulfates (SO42-).
In order to evaluate the tolerance of spinach cv. “virofly” to salinity levels in application with different nitrogen rates, a greenhouse experiment was conducted as completely randomized design based on factorial arrangement with three replications at Shiraz University Agricultural Faculty. Treatments include four levels of salinity (without salinity, 1, 2 and 3 gr of sodium chloride per kg of soil, equivalents to 0.7, 4.5, 8 and 11.5 dS/m in saturated solution extract of soil, respectively), and five levels of nitrogen (unfertilized, 75, 150, 225 and 300 mg N/kg of soil) as urea source. Nitrogen treatments were applied in two installments in water soluble (half before planting and another half, 20 days after planting). In order to prevent sudden stress, saline treatments were applied gradually after complete plant establishment with irrigation water. The irrigation of the pots was carried out with distilled water and at field capacity. After 56 days of sowing, in every pot the spinach shoots were discarded near the surface of the soil and the required parameters were measured.
The application of 4.5 and 8 dS/m salinity had no significant effect (≤0.05) on the relative yield and spinach leaf area, but 11.5 dS/m salinity significantly (≤0.05) decreased relative yield and spinach leaf area compared to without salinity level, 4.5 and 8 dS/m. Nitrogen application (75 and 150 mg/kg of soil) alleviated negative effect of salinity on yield and leaf area. Application of 225 and 300 mg N/kg of soil with 11.5 dS/m salinity significantly decreased the relative yield of spinach. The highest and lowest shoot water content changes in salinity conditions were observed in no-nitrogen application and 150 mg N/kg application, respectively, which shows that the application of nitrogen in the medium level controls the water changes in the spinach plants. In this study, increasing the amount of nitrogen at all levels of salinity, elevated the shoot water content. The tolerant plant species in the face of environmental stresses maintain the water content of their cells in the higher levels. Therefore, it can be said that the maintenance of high leaf water content is an important mechanism for tolerance to salinity, and the cultivars that can hold more water in their leaves under stress conditions, will have more tolerance to salinity stress. Linear regression (R2 = 0.8198) showed that in the salinity levels of 4.5 to 11.5 dS/m, there is a negative relationship between the yield and the chlorine to nitrogen ratio (Cl/N) of spinach shoots, so that with increasing Cl/N, the spinach shoot yield decreased by gradient of -3.077. Application of nitrogen up to 225 mg/kg of soil gradually reduced the ratio of K/Na, Ca/Na and Mg/Na, however, the application of 300 mg N/kg of soil had no significant effect on these ratios. The application of different levels of salinity gradually reduced the K/Na, Ca/Na and Mg/Na ratio.
The threshold of salinity of spinach cv. “virofly” was about 8 dS/m in our study, this was above the threshold mentioned (2 dS/m) for spinach in most sources. The application of nitrogen in medium level as urea can improve the negative effects of salinity in spinach but intensive nitrogen fertilization may increase the negative effects of salinity on plant yields.

The plant growth promoting bacteria (PGPB) inhabiting the phyllosphere of different plants provides a tool for more efficient use of bacteria as a source of biofertilizers. The use of molecular technologies leads to in-depth research of the phyllosphere microorganisms and may provide new avenues for the development and validation of modern agricultural operations and significantly increase productivity. The aim of this research was to investigate the plant growth promoting (PGP) traits of bacteria isolated from maize (Zea mays L.) phyllosphere cultivated in different geographical zones of country (Iran) and their molecular identification by 16Sr RNA sequencing.

In September (2016), 116 samples of healthy mature leaves were collected from the maize fields located in 6 provinces of Iran (Fars, Alborz, Qazvin, Khuzestan, Tehran and Khorasan) and then, phyllosphere bacteria were isolated from them. Growth promoting traits of bacteria including Indole-3 Acetic acid (IAA) production, organic phosphate dissolution, siderophore production, exopolysaccharides (EPS) production and also nitrogenase enzyme activity were measured using standard methods. Superior strains were identified based on 16S rRNA sequencing method.

The 10 from 242 bacterial strains isolated from maize phyllosphere were selected based on their growth promoting traits. All strains selected demonstrated nitrogenase activity, organic phosphate dissolution and IAA and EPS production capability. The highest nitrogenase activity (70.31 nM ml-1 h-1) and organic phosphate dissolution (75.05 g l-1) were observed in THE15 strain, while the lowest amount of these properties belonged to KHO57 (5.55 nM ml-1 h-1) and KHO51 (15.90 g l-1) strains, respectively. The QAZ26 and TEH15 strains had the highest amount of IAA production (31.56 and 30.00 µg ml-1, respectively) and the ALB32 strain produced the lowest amount of IAA (4.50 µg ml-1). The EPS production by strains ranged from 0.120 to 1.805 g l-1. Among the strains investigated, only KUU32, KHU53, ALB32 and QAZ26 were able to produce siderophore. 16S rRNA sequencing revealed that the 10 strains selected belong to Bacillus, Microbacterium, Pseudarthrobacter, Pseudomonas, Stenotrophomonas, Enterobacter and Kocuria genera. The Bacillus with 4 different species (including Bacillus subtilis, Bacillus megaterium, Bacillus paralicheniformis and Bacillus pumilus) was the most dominant genus.

Based on the results of this study, Bacillus was the most dominant genus of plant growth promoting bacteria in the maize phyllosphere. Among the isolated bacteria, Enterobacter hormaechei TEH15 was highly capable of nitrogenase enzyme activity, IAA and organic phosphate solubility. Therefore, this strain deserves further research in greenhouse and field studies of maize cultivation and maize family plants.

Soil salinity is one of the important stresses in agricultural production and plays an important role in reducing the growth of crops such as tomatoes. The proper concentration of calcium in salinity conditions is an important factor in controlling sodium and chlorine toxicity and increasing the yield of sensitive plants especially tomatoes. This research was carried out to study the effect of salinity and supplemental calcium on growth, concentration of some nutrients and fruit quality of tomato under hydroponic conditions.

For this purpose, a factorial experiment was conducted on the based on a completely randomized design with three replications in year 89-90 in the greenhouse of the Soil Science Department of Shiraz University.  The treatments consisted of three levels of salinity (0, 10 and 20 mM) from sodium chloride and three levels of calcium (0, 5 and 10 mM) from calcium nitrate source.

The results showed that the application of supplemental calcium in saline conditions to the nutrient solution reduced the negative effects of salinity and high sodium and chloride on tomato growth, although this supplemental calcium did not improve the growth and yield of the fruit, but could be considered as a competitive factor in the absorption of other cations by the plant.

The results showed that the sodium chloride had a negative effect on root and shoot dry weight, but this weight loss was significant only for the root (25.77% decrease compared to the control sample). Increasing salinity reduced the amount of nitrogen in the shoots. Changes in potassium were not significant in shoots, but in the root with increasing salinity and calcium, potassium absorption decreased. The lowest potassium uptake in the root was obtained from treatment with salinity of 20 mM and no supplemental calcium. Sodium chloride (salinity) treatment increased root and shoot sodium concentrations, and supplementation of calcium reduced the sodium concentration in them. The highest amount of magnesium absorption in shoots was in salinity treatment (20 mM) and without calcium, and the lowest magnesium adsorption was in non-saline treatments with 10 mM calcium. Salinity increased the concentration of manganese, zinc and copper in shoots and increased zinc in the root.

Direct use of poultry manure (PM) as an organic fertilizer in agriculture may cause environmental concerns; therefore, application of its biochar might be an effective solution. A greenhouse experiment was conducted to investigate the influence of PM and its biochar (PMB) (control, 1% and 2% PM (w/w), 1% and 2% (W/W) PMB) on the growth and micronutrients concentration of corn under salinity stress (0.5, 3.6, 7.9 and 12.4 dS m-1) in the presence or absence of arbuscular mycorrhizal fungus (AMF) (Funneliformis mosseae). Results indicated that application of PM and PMB significantly increased corn shoot dry weight (SDW) compared to that of control in non-AMF plants. However, SDW was higher in PMB application compared to that of PM by 15% and 8% for 1% and 2% (w/w) application rates, respectively. In AMF-plants, addition of 2% PMB had no significant effect on SDW compared to that of control. Hence, co-application of PMB (2%), and AMF did not increase SDW due to the fact that AMF was ineffective to enhance corn yield (at high phosphorous (P) concentration in 2% PMB rate). Salinity stress, at low levels (3.6 and 7.9 dS m-1), increased SDW of corn but at a higher level (12.4 dS m-1), decreased it significantly, in both non-AMF and AMF plants. In general, shoot micronutrients concentration (except for Cu) significantly increased along with increasing soil ECe levels in AMF and AMF plants. In non-AMF plants, only addition of 2% PMB increased shoot Mn concentration by 20% compared to that of control. However, in AMF plants, application of PM (2%) and PMB (1% and 2%) decreased Mn concentration by 27%, 16%, and 9% compared to those of control treatment, respectively. Poultry manure biochar increased corn shoot Zn, Cu and Fe concentrations compared to those of control due to the higher concentration of these nutrients in biochar compared to PM. In conclusion, pyrolysis of PM almost eliminated foul odor of PM and increased dry matter yield of corn.

In order to investigate the effect of sodium chloride application, organic matter sources and growth promoting bacteria on fresh and dry matter yield and concentration of micro nutrients in shoot of spinach, a factorial experiment was conducted in a completely randomized design with three replications. The treatments were sodium chloride (control (S0), 2 (S2) and 4 (S4) g Na Cl kg-1 soil), organic matter (control (OM0), 0.5% and 1.0 % rice husk and 0.5% and 1.0 % rice husk biochar, w/w)  and PGPR bacteria (without and with bacteria). Results showed that application of 2 and 4 g salt kg-1 of soil slightly increased iron concentration of aerial part, while Cu concentration increased by 48.10% and 48.32%, respectively. However, Zn and Mn concentrations decreased. Plant yield was not affected by salinity, probably due to the osmotic adjustment resulting from gradual increase in salt addition. Application of organic matter sources increased spinach fresh and dry weight, and Fe, Zn, Cu and Mn concentrations. Inoculation with Pseudomonas fluorescence significantly increased fresh and dry weight as well as Fe, Zn, Cu, and Mn concentrations in aerial part, compared with the related control (without bacteria(. In conclusion, spinach (cv Virofly) very well tolerated gradual addition of salinity; and application of organic matter with growth promoting bacteria increased micronutrients concentration and growth of spinach in a calcareous soil affected by salinity.

In order to investigate the effects of application of sodium chloride, organic matter, and growth promoting bacteria on fresh and dry shoot weights and also concentration of some nutrients in aerial parts of spinach, a factorial experiment was conducted in a completely randomized design with three replications.  The treatments consisted of three levels of sodium chloride (control (S0), 2 (S2) and 4 (S4) g Na Cl kg-1 soil equivalent to 0.7, 8 and 16.8 dS/m, respectively), five levels of organic matter (control 0%(OM0), 0.5% (RS0.5) and 1% (RS1) % rice husk and 0.5% (Bi0.5) and 1% (Bi1) % rice husk biochar, w/w)  and two bacterial levels i.e. without (P0) and with bacteria (P1). Results showed that increasing salinity levels significantly increased spinach dry weight, but significantly decreased concentrations of N, P, Ca and Mg in aerial part, while concentration of Na increased. With the use of organic matter sources, fresh and dry weights of spinach shoot and con fluorescence [H1] centration of all nutrients increased significantly. Also, addition of Pseudomonas fluorescence significantly increased fresh and dry weights and concentration of nutrients of spinach aerial part .According to the results obtained in this study, it can be concluded that the use of organic matter as a soil amendment and rich source of nutrients can greatly increase concentration of nutrients in spinach. Also, addition of Pseudomonas fluorescence as a biofertilizer can improve spinach growth and increase concentration of some nutrients in spinach aerial part under salinity conditions. Application of organic matter and bacteria in salinity-free conditions increased concentration of nutrient and yield of plant. In general, further investigations under field conditions are necessary to verify the results of the present study.  [H1]?

Nowadays, recycling of organic wastes produced in food and medicinal factories by applying them to agricultural lands as organic fertilizers is the focus of attention. The present study was carried out to compare the effect of applying organic wastes of four factories in Fars and Khuzestan provinces and their biochars on some of the chemical properties of a calcareous soil. An experiment was conducted for two months in a completely randomized design based on a factorial arrangement (9 × 4), including 9 organic waste types (filter cake, bagasse, bagasse-biochar, sugar beet, sugar beet-biochar, licorice, licorice-biochar, soybean meal and soybean meal-biochar) at 4 rates of application (0, 1%, 2% and 3% by weight) with three replications. The results showed that interaction effects of organic waste types and rates, on the soil available phosphorus (P), soil DTPA-extractable iron (Fe), copper (Cu) and manganese (Mn) concentrations and electrical conductivity (EC) were significant. The soil amended with soybean meal had the highest nitrogen (N) and Cu content. Filter cake was a good source for P, zinc (Zn) and Fe and sugar beet pulp was a good source for Mn. There was no significant difference in the amounts of available nutrients between raw organic materials and their biochars. Although the increase in the level of application of these wastes by two to three percent by weight increased the accessibility of these elements, the application of higher levels of these wastes was accompanied by 33% to 166% increase in soil electrical conductivity; so, widespread use of these wastes should be done more cautiously.

A greenhouse experiment was conducted in a completely randomized design with factorial arrangement to investigate the influence of biological treatments (Pseudomonas fluorescens, Micrococcus yunnanensis, Claroideoglomus etunicatum and Funneliformis mosseae) on Vetiver grass grown on a crude oil contaminated calcareous soil (0, 2 and 4% crude oil). Results showed that the shoot and root dry weight and root colonization decreased in crude oil treatments. While the microbial respiration and total hydrocarbon concentration in post-harvest soil increased significantly. Soil inoculation with Micrococcus yunnanensis and Funneliformis mosseae had a positive effect on shoot dry weight but not for Pseudomonas fluorescens treatment. Iron concentration and iron and zinc concentrationsenhanced significantly in Claroideoglomus etunicatum and Funneliformis mosseae treatments respectively. Root colonization also increased when mycorrhiza inoculation applied to soil samples. Micrococcus yunnanensis and Funneliformis mosseae increased microbial soil respiration and total hydrocarbon content reduced in post-harvest soil. Our result showed that among tested microorganisms, Micrococcus yunnanensis and Funneliformis mosseae had more positive effects on bioremediation and plant growth in crude oil contaminated calcareous soil.

 Zinc deficiency is aggravated mainly in arid and semi-arid regions, due to low organic matter and soil moisture as well as high levels of pH and salinity. Maize which serves as staple food is sensitive to Zn deficiency. One of the mechanisms by which plants can adapt to nutrient deficient soils has suggested producing and secreting organic substances, including aliphatic low molecular weight organic acids, into the rhizosphere for mobilization and uptake of nutrients. Under Zn deficiency, plants tend to modify rhizosphere in order to increase Zn phyto-availability. Zinc mobilization efficiency is dependent upon the amount and type of organic acids exuded by plant roots and physiochemical properties of soil. Therefore, the objectives of the present study were to investigate the influence of Zn deficiency on the shoot and root dry matter yields and the release rate of organic acids (malic, citric and acetic acids) commonly identified in root exudations of maize under Zn deficiency conditions. Seeds of maize (SC703 and SC704) were surface sterilized and germinated in perlite moistened with distilled water. After seven days, the seedlings were transferred to 5-L containers with continuously aerated nutrient solution. Three Zn levels (0, 0.5, and 1 µM) were added to nutrient solutions. Ten weeks after maize emergence, intact plants were removed from nutrient solution and after two hours of the onset of the light period, roots samples were in opaque vessels containing fresh solution.  The volume of collected solution was sufficient to submerge the whole maize roots samples. After three hours, roots samples were removed from the vessel and solution containing roots exudates was filtered and frozen at −20 ◦C until analysis of organic acids was performed. Organic acids were analyzed using high performance liquid chromatography (HPLC). Organic acids in the samples were identified by comparison with the retention time and absorption spectra of pure standards including malic, citric and acetic acid. The 1-cm washed root segments were placed in a beaker containing 10 mL deionized water and then root samples were immersed at 30◦C for three h, and then conductivity of solution was measured. The samples were boiled for 2 min, cooled to room temperature (25◦C) and then EC samples were measured. The electrolyte leakage was calculated as follows:   Where C1 and C2 are electrical conductivities measured before and after boiling, respectively.  Roots and shoot samples were ignited at 580 ◦C in an oven for 5 h and Zn concentration measured using atomic absorption spectroscopy (AAS). In both genotypes shoot dry matter yield (SDMY) was significantly improved with increasing Zn concentration in nutrient solution. The highest value of SDMY was 19.8 g and belonged to Zn-adequacy level (1 µM) in SC703 genotype which had no significant difference with SC704 under the same treatments. There was no significant difference between Zn-sufficient and Zn-deficiency (0.5 µM) in SDMY in genotype SC703 whereas, a significant difference was observed at the same treatments in genotype SC704. The lowest value of SDMY was 14.7 g and belonged to the Zn-free treatment for genotype SC704. Root dry matter yield (RDMY) significantly increased with increasing Zn concentration in nutrient solution in both genotypes. The highest value of RDMY was 9.6 g and belonged to the treatment of Zn-adequacy for SC703 genotype which had no significant difference with SC704 genotype under the same treatment. The lowest value of RDMY was 4.8 g which was observed in Zn-free treatment for SC704 genotype. Results showed that the rate of organic acid exudation in both Maize genotypes decreased with increasing Zn levels in nutrient solution. The highest rate of MA exudation (6.6 mg /g root dry weight) was observed in Zn-free (Zn0) treatment in SC703 genotype and the lowest rate (1.98 mg g RDW-1) was observed in 1µm Zn treatment in SC704 genotype. Similar to MA, the rate of citric acid (CA) exudation rate significantly decreased with increasing Zn levels in nutrient solution. The highest rate of CA exudation rate was 1.06 (mg gRDW-1) and observed in Zn-free (Zn0) SC703 genotype. The lowest rate of CA was observed in 1µm Zn treatment SC704 genotype 0.2 (mg gRDW-1). The concentration of acetic acid (AA) was below the detection limit of HPLC in Zn sufficient and Zn deficiency treatments. However, AA concentrations in Zn-free were 0.66 and 0.25 (mg gRDW-1), respectively in SC703 and SC704 genotypes.    The rate of MA was significantly higher than CA (4times) and AA (15 times higher). All organic acids exudation rate decreased with increasing Zn concentration in nutrient solution. There was a negative relationship between root and shoot Zn concentration with MA and CA exudation rate. MA, CA and AA exudation rate decreased as the concentration of Zn increased in root and shoot of maize. Roots membrane permeability decreased with increasing Zn concentration in nutrients solution which led to the reduction in root exudations. In both maize genotypes, the highest rate of root membrane permeability belonged to the Zn-free treatment (Zn0) which had the highest root exudation of organic acid and the lowest rate was observed in1µM Zn level  with the lowest rate of organic acid exudation. It seems that Zn concentration in maize shoot control the release of root exudation of organic acids. In general, based on the results it can be concluded that SC703 genotype was more tolerant to Zn-deficiency compared to SC704 genotype partly due to the higher release rate of root organic acids. Further investigation is required to fully understand the physiology of organic acids release under Zn deficiency conditions.

Salinity is among the most important stresses worldwide that affect the absorption and transport of nutrients to plants due to its high sodium concentration. The objective of this study was investigate the possibility of using high adsorption capacity of biochar for increasing sodium adsorption, reducing sodium to potassium ratio of the plant and reducing the negative effect of salinity on plant growth, concentration and uptake of nitrogen and phosphorus with use of mycorrhizal as an bio-amendment. This research was conducted with factorial arrangement in completely randomized design with three replications. Treatments consisted of five levels of organic substances (control, poultry manure (PM)(1% and 2%), poultry manure biochar (PMB) (1% and 2%), four salinity levels (0.5, 3.6, 7.9 and 12.4 dS.m-1) and two fungus levels (control and inoculated with Funneliformis mosseae). Application of PM and its biochar significantly increased growth, greennessindex, concentration and uptake of macronutrients, but decreased percentage of root colonization. Application of PM significantly increased corn plant sodium concentration. Application of PMB had no significant effect on sodium concentration compared to the control treatment, but significantly reduced shoot sodium/potassium ratio (Na+: K+) by increasing potassium concentration. Biochar application at high levels of salinity (7.9 and 12.4 dS.m-1) significantly reduced shoots Na+: K+ ratio. AMF application did not affect plant growth due to the high amount of phosphorous at 2% PMB treatment. In general, results indicated that corn dry matter yield at co-application of fungus and 1% biochar treatment was similar to 2% PM treatment and also, did not inhibit the effectiveness of fungus in reducing the shoot sodium to potassium ratio at high salinity levels.

Salinity and organic matter deficiency are the main problems of soils in arid and semi-arid regions. The use of residues in presence of salinity may affect soil properties differently. In this research, the effect of zero, 1. 5%, 3%, and 4. 5% application of pistachio residues and electrical conductivity (salinity) of water including three levels of 4, 8, and 12 dS m-1 were investigated on water repellency of soils with three different textures, namely, silty clay, loamy, and loamy sand. The static and dynamic water repellencies were determined by measuring soil-water contact angle and water penetration time. The mean values of soil-water contact angle for clay, loam, and sandy loam soils were 70±2. 5º, 65±2. 6º, and 62 ±3. 4º, and water droplet times (WDPT) were about 35±2. 6, 26±1. 6, and 18±0. 6 s, respectively. Accordingly, static water repellency of the fine textured soil was more than that of the medium and coarse textured soils by 3% and 7%, respectively, while the dynamic water repellency was 24% and 95% more, respectively. Salinity had no significant effect on static or dynamic water repellency. However, the salinity of 12 dS. m-1 increased the static water repellency of clay soil by 7%. The residues increased the static and dynamic water repellency of soils, except in silty clay soil where the effect of residues on static water repellency was not significant. In general, salinity levels had no significant effect on the mean values of the static and dynamic water repellency of soils; whereas application of residues (except for 4. 5% residues) increased both static and dynamic water repellency. Furthermore, since the applied residues were probably not fully decomposed in the time period used in this study, it is recommended that longer or different time periods be used in the future studies. 

Application of arbuscular mycorrhizal fungi (AMF) and vermicompost in agriculture as promoting factors to improve the soil quality and plant nutrition, plant growth and yield, is considered as an important and valuable findings in soil fertility and plant nutrition. In order to study the effect of vermicompost and Rhizophagus irregularis fungi on some growth and nutritional responses of two wheat cultivars, a factorial experiment was conducted in completely randomized design (CRD) in greenhouse conditions. Treatments were included: two levels of Rhizophagus irregularis fungi (with and without fungi), two levels of vermicompost (with and without) and two wheat cultivars (Bahar and Shiraz). The results showed that the application of vermicompost increased the mean grain and straw yields of wheat cultivars by 57.8% and 65.6%, respectively, compared to the control. So that, grain and straw yields, total uptake of P, concentration and total uptake of N, total uptake of K and the percentage of root colonization in Bahar cultivar were significantly higher than Shiraz cultivar. The same results obtained in Rhizophagus irregularis fungi treatment. Remarkable increase was observed in the concentration and total uptake of P and N in straw for Bahar cultivar compared to the control. Whereas there is no significant effect on Shiraz cultivar. Rhizophagus irregularis fungi also induced higher root colonization for Bahar cultivar (35.48% increase) compared to Shiraz cultivar. In general, Bahar cultivar was superior to Shiraz cultivar both in term of shoot yield and response to vermicompost and fungi application.

Phytoremediation is a technique for removal of heavy metals including cadmium (Cd) from soils; which is less expensive compared to other methods. Due to the fact that this method is time consuming with low efficiency, hence, other methods are proposed to increase the efficiency of phytoremediation. One method is the application of organic residues to the soils. A greenhouse experiment was conducted to study the effects of the application of wheat or alfalfa residues on phytoremediation of Cd-contaminated calcareous soil by corn. The experiment was a factorial 2×3×3 arranged in a completely randomized design. Treatments consisted of the two types of the organic residues (wheat and alfalfa) in three levels (0, 1, and 2% by weight) and three levels of Cd application (5, 15, and 25 mg kg-1) with three replications. Results indicated that increasing the Cd levels, significantly increased the Cd concentration in soil and in the corn shoots, but decreased the dry weight of the corn and bio-accumulation factor (BAF) of Cd. Increasing the levels of wheat and alfalfa residues significantly increased the Cd concentration in the corn shoots and BAF. Addition of the wheat residues resulted in a higher Cd concentration in the corn aerial parts and BAF compared to those with addition of the alfalfa. However, the corn mean shoot dry weight was significantly higher in the soil amended with the alfalfa residues compared to those amended with the wheat residues. Influences of the wheat or alfalfa residues addition on the Cd uptake by corn were similar. Phytoremediation efficiency of the corn at low Cd levels was higher than that at high rates of the applied Cd.

Co-application of biological fertilizers and phosphate sources have greatly considered in calcareous soilsin recent years. In order to study the effect of phosphate solubilizing bacterium (PSB), phosphate sources and vermicompost on some growth characteristics of lettuce (cv. Ferdos), a greenhouse experiment was conducted with factorial arrangement in a completely randomized design with three replications and three factors. Factors consisted of two levels of phosphate solubilizing bacterium (Pseudomonas flouresence) (with and without inoculation), two levels of vermicompost (0 and 1% w/w) and four phosphate sources (control, rock phosphate, tricalcium phosphate (TCP) and triple super phosphate at 25 mg P kg-1 soil). Biological fertilizers significantly increased shoot fresh and dry weights (SFDW), but they didn’t have remarkable effect on lettuce height. Application of rock phosphate and tricalcium phosphate (TCP) increased dry and fresh weight, respectively. Application of triple super phosphate significantly increased SFDW and lettuce height. Co-application treatments of bacterium, vermicompost and phosphate sources (except super phosphate) significantly increased SFDW, leave numbers and phosphorus concentration of lettuce. Overall, the results indicated that phosphorus chemical fertilizers can be replaced by co-application of insoluble phosphate and biological fertilizers.

Phosphorus is one of the important macro nutrients. Available phosphorus in calcareous soils is low, due to high pH and calcium carbonate, and low amounts of organic matters and moisture, also phosphate minerals are insoluble in such conditions. Arbuscular mycorrhiza inoculation for improving plant growth and yield has become so attractive recently. The symbiosis between plant roots and arbuscular mycorrhizal fungi with increasing phosphorus uptake (through phosphorus uptake by extra and intraradical mycelia and also solubilizing inorganic and organic insoluble phosphates), other nutrients and water cause increase in plant growth. Vermicompost increases the growth of plants due to having nutrients, plant growth regulators and beneficial microorganisms. This research was conducted to evaluate the effect of arbuscular mycorrhizal fungi, vermicompost and phosphate sources on root colonization, shoot fresh and dry weights, number of leaves, chlorophyll index and phosphorus uptake of lettuce in a calcareous soil.
A greenhouse experiments was conducted with factorial arrangement in a completely randomized design with three factors and replications in a calcareous soil. Treatments consisted of two levels of arbuscular mycorrhiza (Claroideoglomus etunicatum (AM)) (with and without inoculation), two levels of vermicompost (0 and 1% w/w) and four phosphate sources (control (P0), rock phosphate (RP), tricalcium phosphate (TCP) and triple super phosphate (SP) at 25 mg P kg-1 level). Non sterile soil was used and its characteristics along with vermicompost were analyzed by standard methods. Seeds of lettuce (Lactuca sativa) cv. Ferdos were planted. After 10 weeks after planting, chlorophyll contents, leaves numbers, fresh and dry weights, root colonization and phosphorus uptake were measured. Data were analyzed with SAS statistical software.
Application of vermicompost increased root colonization and phosphate sources decreased it. The highest rate of root colonization was observed in co-application treatments of vermicompost and arbuscular fungus and in the absence of phosphate sources. Mycorrhizal inoculation increased shoot dry weight and phosphorus uptake. Vermicompost application increased shoot fresh and dry weights, number of leaves, chlorophyll index and phosphorus uptake. Application of SP increased shoot fresh and dry weights and decreased chlorophyll index and phosphorus uptake. Application of RP decreased chlorophyll index and increased shoot dry weight and phosphorus uptake. Co-application of mycorrhizal fungi, vermicompost and phosphate sources increased shoot fresh and dry weights, number of leaves and phosphorus uptake.
Application of biofertilizers (vermicompost and arbuscular fungi) along with insoluble phosphate source (RP and TCP) can be increased phosphorus uptake and plant growth and reduced the consumption of chemical fertilizers especially SP.

Application of chemical fertilizer is one of the methods to supply nutrient elements for plants and it is an effective method to meet plants nutrients demands; but organic fertilizers such as biochar application can be used as a proper solution to decrease gases resulted from agricultural activities, increase soil's organic matters and to manage soil fertility. Biochar can increase soil fertility of some soils, increase agricultural productivity, and provide protection against some foliar and soil-borne diseases. Biochar is a high-carbon charcoal used as a soil amendment and it is made of plant biomass and produced during pyrolysis process in the absence of oxygen. The ability of biochar to store C and improve soil fertility will depend on its physical and chemical properties, which can be varied in the pyrolysis process (pyrolysis temperature) or through the choice of raw materials.
In order to study the effect of pistachio residue biochar produced in two different temperatures and chemical fertilizer on macronutrients concentration and growth of spinach (viroflay) (Spinacia oleracea), a greenhouse experiment was conducted in a factorial (2×3×3) arranged in a completely randomized design with three replications. Treatments consisted of three biochar levels (0, 3, and 6% by weight) prepared at two temperatures (200 and 400 °C), and three fertilizers level [0 (blank), (Nitrogen=80 and Phosphorous=15 mg kg-1 soil) and (Nitrogen =150 and Phosphorous =30 mg kg-1 soil)]. Bulk soil sample was collected from the surface horizon (0–30 cm) in Bajgah Agricultural Station of Shiraz University, Iran. Pots contained 2 kg dry soil. Treatments were added to all pots uniformly and were mixed. Then soil samples incubated in 25 ̊C for 30 days; and soil moisture was kept at about field capacity (FC). Following incubation time, based on soil analysis nutrients were added to all pots uniformly. Ten seeds were sown in each pot, and soil moisture was kept at about field capacity. Spinach seedlings were thinned to five uniform plants per pot 15 days after emergence. The pots were then maintained under FC. Plants were harvested after 8 weeks after emergence. Aerial parts of spinach plants were separated and oven dried and were weighed and ground. Total nitrogen (N), phosphorous (P) and potassium (K) in plants were measured. Statistical analysis was performed using SAS and Excel statistical software packages.
Results showed that biochar prepared at 200 and 400 ̊C had no significant effect on spinach dry weight (DW). Chemical fertilizer significantly increased average of spinach DW. Chemical fertilizers improved N and P concentration in plant, therefore increase growth of spinach than control. Biochar prepared at 200 and 400 ̊C significantly increased shoots N, P and K concentration of spinach compared to that of control; but biochar prepared at 400 ̊C had significant effect on shoots N and P concentration. Biochar might be direct nutrition resources for plant and supply many nutritional elements such as N, P and K for plant and increase concentration of these elements in plant. Application of chemical fertilizer significantly increased N and P and significantly decreased K concentration in spinach shoot. Several studies showed that application of biochar improved efficiency of nitrogen fertilizer in several soils and finally more nitrogen absorbed by plant. Biochar prepared at two temperatures had no significant effect on DW and shoot N concentration of spinach. However, addition of biochar prepared at 400 ̊C significantly decreased shoot P concentration and significantly increased shoot K concentration in spinach, as compared to biochar prepared at 200 ̊C.
Results indicated that application of biochar prepared at 200 and 400 ̊C improve composition of spinach but had no effect on its DW, probably because of short term of plant growth, kind of biochar, and biochor levels. Applications of biochar, increased shoot N and P concentration; it might be due to improving physical, chemical and biological properties of soil with addition of biochar. Also, biochar supplied nutritional elements and improve efficiency of chemical fertilizer; therefore it is appropriate that biochar applied with chemical fertilizers. Our results showed that 6% biochar level was the best suggested levels that in three chemical fertilizer levels increased shoot N and P concentration of spinach. With increasing temperature for preparing biochar, pH of biochar increased; so, it might be concluded that biochar prepared at low temperature was appropriate than biochar prepared at high temperature for application to calcareous soils.

This study was conducted to investigate the effects of poultry manure (PM) and derived biochars on phosphorous (P) availability and apparent recovery in a calcareous soil. Treatments consisted of four rates of P (0, 30, 60 and 90 µgg-1) and five organic substances (blank, poultry manure and derived biochars at 200, 300 and 400°C). organic substances were incorporated with 400 g of soil at 2% level (w/w). All soil treated samples plus control were incubated for 150 days. Soil P availbility determined at 8 different stage of incubation time period. Phosphorous availability was less in untreated soil samples with organic substances and also decreased with time. Although P recovery from inorganic P fertilizer was high in the early stages of incubation time compared to treated soil samples but decreased with time, if not treated with organic substances. Phosphorus availability and recovery increased with time in PM and biochares treated soil samples. Simultanous application of inorganic P and organic substances decreased apparent P recovery. Negative interaction obsorved between organic substances and high rates of inorganic P fertilizer on P availability. It was concluded that PM biochar prepared at 300°C had the highest effect on adjusting P availability in calcareous soil.

Plants can uptake, bioaccumulate and immobilize different metals in their tissues. Phytoremediation technique has been used to remove hazardous substances including heavy metals from the environment. Assisted phytoremediation is usually the process of applying a chemical additive to heavy metal contaminated soils to enhance the metal uptake by plants. The main objective of present study was to investigate the effectiveness of plant growth regulators (PGRs) and a humic substance (HS) on Ni phytoremediation by maize in a Ni-pollutrd calcareous soil.
The experiment designed as a 5×3 factorial trial arranged in a completely randomized design with three replicates. Three kilograms of soil was placed in plastic pots and pots were watered with distilled water to field capacity and maintained at this moisture level throughout the experiment by watering the pots to a constant weight. The soils were polluted with 250 mg Ni Kg-1 as Ni-nitrate Ni (NO3)2. Six maize (Zea mays L.) seeds were planted 2 cm deep in soil and thinned to three uniform stands 1 week after emergence. Treatments consisted of three levels of soil application of commercially humic substance, HS, (0, 3, and 6 mg kg as Humax 95-WSG containing about 80% humic acid, and about 15% fulvic acid) and five levels of PGRs (0 or 10 µM GA3, IAA, BAP and SA). The HS was applied as split doses in three times at 15 day intervals along with irrigation water. The seedlings were exposed to aqueous solutions of HS 16 days after sowing for the first time. Prepared solutions of PGRs were sprayed three times at 15 day intervals from emergence. Seven weeks after planting, shoots were harvested and roots were separated from soil carefully, both parts were rinsed with distilled water and dried at 65°C for 72 h, weighed, ground, and dry meshed at 550°C. Root and shoot dry matter and Ni concentration and uptake and phytoremediation criteria were considered as plant responses. Data were statistically analyzed using SAS and SPSS software packages. Application of different PGRs had no considerable effect on phytoextraction or translocation efficiencies. Among the four PGRs studied application of SA and BA significantly increased mean uptake efficiency.
Among four PGRs evaluated, application of GA3 increased mean shoot dry matter yield and application of SA increased mean root dry matter yield. Application of the highest HS level (6 mg kg-1) decreased both mean root and shoot dry weight. Application of SA increased Ni concentration in both maize root and shoot. Application of BA only increased Ni concentration in maize root. Although application of the highest HS level (6 mg kg-1) caused an increase in Ni concentration in maize shoot, this effect was attributed to the influence of HS on the decrease in decreasing dry weight of maize shoot. Application of all PGRs except GA3 increased leaf greenness criterion. Addition of HS had no significant effect on leaf greenness. Application of PGRs enhanced root concentration factor (RCF) and decreased translocation factor (TF). Among PGRs evaluated, BA was the most effective on TF, and SA or BA was the most effective on RCF. However HS were not significantly influenced these phytoremediation criteria, as compared with control. The efficiency of PGRs in root Ni uptake was in the order of SA > BA > GA3 > IAA. Application of BA had a significant effect on Ni distribution among root and shoot, in comparison with other PGRs, and caused an increase and a decrease in root and shoot uptake of Ni, respectively. However HS had a negative effect on tolerance index and its application decreased root and shoot dry weights. Results showed that the values of Ni in maize root was considerably higher than that of maize shoot demonstrated that phytostabilization was the main mechanism involved in the phytoremediation of Ni by maize and application of PGRs was effective on this mechanism.
Results reported here indicated that although the addition of HS did not cause a significant effect on Ni phytoremediation, application of most studied PGRs had a positive effect on Ni phytoremediation by maize. Application of SA and BA increased uptake efficiency and RCF and application of GA3 increased shoot dry matter and tolerance index. The fact that Ni uptake by roots was significantly higher than that of shoots demonstrated that phytostabilization was the main mechanism involved in the phytoremediation of Ni by maize. According to results reported herein the addition of PGRs especially SA is likely to be promising in phytostabilization of Ni in calcareous soils polluted with this metal.

Vermicompost is one of the important bio-fertilizer which is the product of the process of composting different organic wastes such as manures and crop residues using different earthworms. Vermicomposts, especially those are derived from animal wastes,contain the large amounts of nutrients compaired with the composts prepared from crop residues. Vermicomposts contain plant available form of nutrients such as nitrate nitrogen, exchangeable phosphorus and potassium, calcium and magnesium. Nowadays, the use of vermicompost in sustainable agriculture to improve the growth and quality of fruits and crops is very common. Drought occurs when the amount of moisture in soil and water resources and rainfall is less than what plants need for normal growth and function. Two thirds of farm lands in Iran have been located in arid and semi-arid regions with annual rainfall less than150 mm that has been distributed irregularly and unpredictable during growth season imposing water stress in most crops. It indicates the importance of water management and proposing different strategies for mitigating detrimental effect of water stress in croplands. Due to the fact that crops nutrient management under drought and water stress using organic fertilizers is an effective method in reaching to high yields in sustainable agriculture, the objective of the present study was to investigate the influence of vermicompost application on reducing the adverse effects of water stress on the growth and chemical composition of corn in a calcareous soil.
In order to study the influence of water stress and application of vermicompost on corn dry matter yield and nutrients concentration of corn shoot, a greenhouse factorial experiment (4×3) in completely randomized design with three replications was conducted in college of agriculture, Shiraz university, Shiraz, Iran. The factors consisted of four vermicompost levels (0, 10, 20 and30g kg-1soil equal to 0, 20, 40 and 60 Mg ha-1) and three moisture levels(100, 80and 60%of field capacity(FC)). The soil samples were collected (0-30 cm depth) from a calcareous soil (Fine, mixed, mesic, Typic, Calcixrepts), located at Bajgah, Shiraz, Iran. Soil samples were mixed thoroughly with different levels of vermicompost and transfred to plastic pots. Six corn seeds were planted in each pot and were thinned to three uniform plants, one week after germination. Eight weeks after germination, corn shoots were harvested, dried and recorded. Plant samples were grind using a portable grinder and transferred to the laboratory for chemical analysis. The collected data were statistically analysed using SAS software (9.1.3) package.
The results indicated that with increasing the levels of vermicompost, dry matter yield and concentrations of total nitrogen (TN), phosphorus (P), iron (Fe), copper(Cu) and zinc (Zn) in corn shoots were significantly increased. But, due to the antagonistic relationship between manganese (Mn) and Zn or Fe,concentrations of Mn were significantly decreased. However, the concentration of Mn was in the sufficiency range. The highest dry matter yield and concentrations of nitrogen and phosphorus in corn shoot was observed at 30 g kg-1 vermicompost treatment, with 19, 10 and 20 % increase (compared to the control), respectively. The application of 30 g kg-1 vermicompost increased the concentrations of Zn, Cu and Fe by 41%, 90% and 75%, respectively and concentration of Mn decreased by 11.88%, compared to the control. Increasing the levels of water stress increased significantly the concentration of nutrients in corn shoot due to the reduction of corn biomass. The highest increase in nutrient concentrations was observed at 60% FC moisture level. Nitrogen and phosphorus concentrations in corn shoots by 12.5and 22.5% and Zn, Cu, Fe and Mn by 25, 83, 43and29% were higher compared to those of control (100% FC), respectively. The interaction effects of water stress and vermicompost on the concentrations of shoot N and Cu were significant and both were incresead by simultanoeus application of vermicompost and levels of water stress. The applicaion of 30 g kg-1 vermicompost (about 60 ton ha-1) under 60% FC moisture level increased significantly dry matter yield and the concentrations of nitrogen, phosphorus, zinc, copper and iron in corn shoot by 29%,5.5%, 23, 110, 41 and 71 percent compared to the control, respectively. However, because of the antagonistic relationships,the iron or manganese concentrations were reduced, but were yet in the sufficiency range. The use of 30 g kg-1 vermicompost under 80% FC moisture level Also increased significantly the concentrations of nitrogen, phosphorus, zinc, iron and copper by 9, 23, 24, 59 and 43 percent compared to the control, respectively.
The applicaion of 30 g kg-1 vermicompost increased significantly dry matter yield and the concentration of nitrogen, phosphorus, zinc, copper and iron in corn shoot under water stress treatments. In conclusion, the application of vermicompost mitigated the detrimental effects of water stress on corn dry matter yield and concentration of nutrients due to the positive effects of compost on physical, chemical and biological properties of the calcareous soil.

Water stress is the main cause for crop yield reduction in the majority of agricultural regions of the world because it affects almost all plant functions. The effects of Glomus mosseae on growth, nutrients uptake, and antioxidant enzymes of sour orange (Citrus aurantium) and rough lemon) Citrus jambheri) rootstocks were assessed in sterilized soil under greenhouse conditions. A three-factor experiment was set up in a completely randomized design with three replicates of each treatment. Treatments consisted of water stress at four levels (irrigation intervals of 2, 4, 6, and 8 days) and mycorrhizal treatments at two levels (inoculation with G. mosseae and non-mycorrhizal control). Mycorrhizal seedlings of two citrus rootstocks were successfully infected by G. mosseae. As water stress increased, root colonization, shoot dry weight, shoot N, P, Mn, Cu, and Fe uptake of two citrus rootstocks significantly decreased but shoot Zn uptake and the antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (G-POD) and ascorbate peroxidase (APX)] activities of two citrus rootstocks leaves increased. With inoculation of seedlings by G. mosseae compared with control, shoot dry weight, N and P uptake, and antioxidant enzymes activities increased. It may be concluded that mycorrhizal inoculation notably influenced shoot nutrients uptake and leaves antioxidant enzymes activities in citrus and an increase in these parameters alleviated water stress.

A greenhouse experiment was conducted to study the effect of zinc rates, arbuscular mycorrhiza and organic matter, on corn growth and micronutrients-uptake in a calcareous soil. Experimental design was factorial based on complete randomized design with 3 replications. Treatments consisted of 3 levels of Zn (0, 5 and 10 mg Zn/kg), 2 types of organic manure (sheep manure and municipal waste compost, each at 0 or 1% w/w) and 2 levels of mycorrhiza (no inoculation and inoculation with Glomus intraradices). Plants were harvested 8 weeks after emergence and used for chemical analysis. Roots were used to determine the degree of colonization. Results showed that application of Zn increased plant dry matter weight, total Zn and Cu uptake, root mycorrhizal colonization and decreased total Fe and Mn uptake. Arbuscular mycorrhiza increased plant dry matter weight, root mycorrhizal colonization and total Zn, Fe, Mn and Cu uptake. Application of both organic manures increased plant dry matter weight, root mycorrhizal colonization and total Zn, Fe, Mn and Cu uptake.