Abdolhossein ziaeyan; Ali Reza Farahbakhash; Hossein Besharati; lLadan Joukar
Abstract
Introduction: The most abundant of agricultural soils in Iran, are calcareous. In calcareous soils, phosphorus fertilizers use efficiency is low. The usage of soil microorganisms is one of the effective ways to increment the uptake of phosphorus in calcareous soils. This microorganisms using various ...
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Introduction: The most abundant of agricultural soils in Iran, are calcareous. In calcareous soils, phosphorus fertilizers use efficiency is low. The usage of soil microorganisms is one of the effective ways to increment the uptake of phosphorus in calcareous soils. This microorganisms using various mechanisms, including the production of plant hormones or the production of organic and inorganic acids to dissolve the insoluble phosphorous compounds. Mycorrhizal symbiosis is also one of the most recognized and important symbiosis relationship found in the world. In a mycorrhizal symbiosis,plants can be able to absorb more nutrients and water from soil and fungus plays a protective role as a growth enhancer and make the plants more tolerable to biotic (pathogens) and abiotic (drought, cold and salinity) stresses .This research conducted to study phosphate solubilizing bacteria and mycorrhiza roles on sorghum growth and phosphorus availability to this plant.
Materials and methods: To achieve the desired goals, a pot experiment was conducted as a factorial in completely randomized design with sixteen treatments in three replications. The treatments were combination of four P levels of zero, 25, 50, and 75 mg kg-1 P2O5 from triple super phosphate source, the two treatments of inoculation and without inoculation of phosphate solubilizing bacteria and the two treatments of inoculation and no inoculation of mycorrizal fungus. Required fertilizers based on initial soil test results were supplied. Accordingly, the same amount of nitrogen, 80 mg kg-1 (30 mg kg-1 before planting and 50 mg kg-1 after planting twice) as urea source, 10 mg Zn kg-1 and 5 mg kg-1 Cu per kg soil as the forms of Zinc sulphate (ZnSO4.7H2O) and copper sulphate (CuSO4.H2O) were added to each soil sample. Required Phosphorus also was calculated based on treatments and added to potting soil. Each pot size was 5 kg. every sample was thoroughly mixed and then were placed in pots. At the same time the seeds were inoculated. In harvesting time, some parameters such as plant height and diameter, wet and dry foliage yield, and phosphorous uptake were measured and analyzed statistically. After harvesting time also soils phosphorous content were measured and analyzed.
Results Discussion: The results indicated that by utilizing the phosphate solubilizing bacteria, stem diameter, dry matter yield, phosphorous uptake, and soils phosphorous content after harvesting significantly increased. These findings indicated that the use of phosphate solubilizing bacteria affected plant growth. Such results have been previously reported. Ramezanian (31) reported that application of PGPR will be increase wheat stem height and diameter. Li et al (18) and Larsen et al (16) reported that soil microorganisms, including growth promoting bacteria through a variety of mechanisms such as ACC deaminase production or an increase in available phosphorus can stimulate plant growth and increase height and diameter of the stem. Glick et al (13) showed that plant growth promoting bacteria through the production of plants hormones increases plant height and stem diameter, and ultimately improve plants yield. Increases yield of plants through the use of phosphate solubilizing bacteria previously has been reported by other studies. Mycorrizal inoculation also had a significant effect (P
H. Besharati; R. Motalebifard
Abstract
Introduction: After soybean and palm oil, canola is third important oil seed in the world which belongs to the genus Brassicaceae, that its seeds contain about 40% oil. The per capita consumption of oil in Iran is about 14 kg, so approximately 900 thousand tons of oil will be required for each year. ...
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Introduction: After soybean and palm oil, canola is third important oil seed in the world which belongs to the genus Brassicaceae, that its seeds contain about 40% oil. The per capita consumption of oil in Iran is about 14 kg, so approximately 900 thousand tons of oil will be required for each year. However, only less than 10% of this oil is produced in the country. In recent years, special attention has been paid to canola cultivation in order to increase oil production, so during recent years an apparent increase in canola cultivated lands is significant. In most of these canola cultivated lands, the soil is calcareous therefore; some available nutrients such as phosphorus, iron and zinc are less than the amounts required by plants. Increasing qualitative and quantitative yield of canola in calcareous soils is a priority to canola cultivation improvement. Sulfur plays an important role in oil content of oily seed crops. On the other hands sulfur oxidation in calcareous soils can improve some nutrients availability. The present study was designed to investigate the effect of sulfur on yield, oil content and nutrients uptake and also its impact on soil chemical properties with 8 treatments, in 3 replications.
Materials and Methods: This study was conducted in Ekbatan research station in Hamedan province for 2 years as completely randomized block design with 8 treatments and 3 repetitions. The treatments were: T1: Control (Without sulfur and Thiobacillus), T2: Application of 150 kg sulfur per ha, T3: T2+ Thiobacillus inoculums (2% of applied sulfur), T4: Application of 300 kg sulfur per ha, T5: T4+ Thiobacillus inoculums (2% of applied sulfur), T6: Application of 600 kg sulfur per ha, T7: T6+ Thiobacillus inoculums (2% of applied sulfur) T8: Fertilizing based on soil test without sulfur and Thiobacillus. Thiobacillus inoculant containing about 107 cells of Thiobacillus bacteria which belonged to neutrophile Thiobacilli were prepared at soil biology Dep. of Soil and Water Research Institute. In this research treatments were applied in two separate sites (each site contains 24 plots which their dimensions were 2.4×10 meter). For evaluating the residual effect of treatments, the experiment was carried out in constant plots in second year. Phosphorus, iron, zinc, manganese and sulfate, were not applied to any of the treatments except for T8, and the above mentioned treatments were just received 250 kg urea. These all treatments were applied only in the first year and on the second year of experiment their Residual effects on canola were evaluated. During the growing season agricultural practices such as irrigation, weed and pest control in all units were managed uniformly. Soil chemical data were obtained by analyzing of Ec, pH and bicarbonate each year in May. The leaf and seed samples were taken for essential analysis. When plants growth completed, each plot was harvested separately then canola yield and also the phosphorus, iron and zinc content of shoots and grain were measured.
Results: The results of two years indicated that the treatments had no significant effects on pH and bicarbonate of soil while increasing sulfur application rate, caused a decrease in soil bicarbonate content. In addition to that, the treatments did not affect the yield of canola significantly. In the first year of experiment, treatments had shown significant effects (P=0.01) on glucosinolates, seed sulfur and Cu of leaf, whereas no effect determination was occurred about indices of leaf and seed of canola. the results also suggested an increase of 800 kg in the sixth treatment (600 kg sulfur consumption without Thiobacillus) and canola seed yield of treatment T6 enhancedfrom 3446 kg to 4531 kg per ha. Fertilization treatment (T8) could not increase canola yield, so it confirms that the nutrient concentration in experiment sites were near the critical level for canola.
Conclusion: In total results revealed that different sulfur treatments have no significant and considerable impacts on canola yield and soil chemical properties, and the effects was not observed in the second year of experiment, too. Probably the sulfur consumed or sulfur oxidation in the experiments was not enough to cope with high lime (14%) and buffering capacity of the soil. Also probably the nutrient concentration in test sites were more than critical level for canola and plants absorbed enough nutrients from the soil. No increase in canola yield in fertilization treatments (T8) can confirm this opinion, though. It also seems that there were no favorable conditions (soil moisture) for the oxidation of sulfur in the soil.
A. Golestani Fard; H. Mirseyed Hosseini; Gholam Reza Savaghebi; Gh.R. Savaghebi
Abstract
In this research chemical forms of lead and zinc in bulk and rhizosphere soil of different cultivars of maize and canola were determined by sequential and single step extraction methods. Some factors affecting chemical transformation of the two elements such as pH, dissolved organic carbon (DOC), their ...
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In this research chemical forms of lead and zinc in bulk and rhizosphere soil of different cultivars of maize and canola were determined by sequential and single step extraction methods. Some factors affecting chemical transformation of the two elements such as pH, dissolved organic carbon (DOC), their uptake by plant and also cation exchange capacity in the rhizosphere and bulk soil were also assessed. Rhizosphere was obtained with gentle shaking and separating the soil around plant roots. Results showed that zinc uptake was more than lead in both plant cultivars. Zinc and lead accumulation in all cultivars roots were also more than shoots. Translocation index (The ratio of element concentration in shoot to root) in the corn cultivars was higher than canola cultivars (significant correlation= 1%) while the ratio was higher for lead in canola cultivars. Metal concentration in shoots to total metal concentrations in soil (Accumulation factor) showed a similar trend like the translocation index. In total, the corn ability in zinc and lead absorption and extraction in soil was higher compared to canola. There weren’t any significant changes in rhizosphere pH compared to bulk soil. Dissolved organic carbon in the rhizosphere of different cultivars was more than bulk soil and the amount of it in canola was significantly more than corn cultivars. Among each plant cultivars, the absorption rate increased with increasing root exudates. The results of sequential and single step extraction methods showed that the general trend and the soil system tendency (Root-Soil interface) is toward zinc availability in the rhizosphere. The amount of lead in rhizosphere showed no significant changes to bulk soil with none of the extractants in single step extraction method but with regards to the results of sequential extraction method, rhizosphere processes tend to reduce the availability of this element in both plant cultivars.
M. Mohammadi Aria; A. Lakzian; Gh. Haghnia; H. Besharati; A. Fotovat
Abstract
Abstract
A large number of studies have shown that direct application of rock phosphate dose do not have enough efficiency to release phosphorus compared to chemical fertilizers. The main purpose of this study was to increase the efficiency of direct application of rock phosphate. Incorporation of rock ...
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Abstract
A large number of studies have shown that direct application of rock phosphate dose do not have enough efficiency to release phosphorus compared to chemical fertilizers. The main purpose of this study was to increase the efficiency of direct application of rock phosphate. Incorporation of rock phosphate with sulfur, organic matter and inoculation with sulfur-oxidizing bacteria and phosphorous-solubilizing fungus, seems to be a suitable alternative for increasing the efficiency and applicability of rock phosphate. This experiment was carried out in laboratory condition, using completely randomized factorial design with 12 treatments and 3 replications. The treatments included sulfur at three rates, 0% (S0), 10% (S1), 20% (S2), vermicompost at two rates, 0% (V0), 15% (V15), and inoculation with Thiobacillus thiooxidanc, Aspergillus niger (BF) and without inoculation. Water soluble phosphorus and pH were measured during incubation time (15 and 60 days). The results of experiment showed that water soluble phosphorous increased over the time and the maximum level of water soluble P was observed using treatment of 20% sulfur, 15% vermicompost and inoculated with Thiobacillus and Aspergillus (BFS2V1). The amount of water soluble phosphorus in BFS20V15 was significantly higher than other treatments.
Keywords: Rock phosphate, Organic matters, Water soluble phosphorus
