atena mirbolook; Mirhasan Rasouli-Sadaghiani; E. Sepehr; A. Lakzian; M. Hakimi
Abstract
Introduction: Iron (Fe) is an important micronutrient that plays a role in several crop physiological processes such as photosynthesis, respiration, and synthesis of heme proteins, DNA, RNA, and hormones. The most common Fe source used in agriculture is Fe-EDDHA. However, the usage of this chelate may ...
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Introduction: Iron (Fe) is an important micronutrient that plays a role in several crop physiological processes such as photosynthesis, respiration, and synthesis of heme proteins, DNA, RNA, and hormones. The most common Fe source used in agriculture is Fe-EDDHA. However, the usage of this chelate may be problematic for plant growth. In the recent years, organic chelates have gained attention as they increase the microelements solubility and prevent iron precipitation in nutrient solution. Organic chelates such as amino acids and polysaccharides have many physicochemical (reactive OH, COOH and NH2 groups) and biological (biocompatible and biodegradable) properties that make these attractive materials usable for the agricultural practice. Biodegradability, low toxicity, immune system stimulation, the ability to coordinate metal, less sensitivity to photodegradation, and the effect on physical properties of rhizosphere and root growth dynamic are ideal properties of these components. The objective of this study was to evaluate Fe-organic-chelates efficiency as Fe sources for bean (Strategy I) and corn (Strategy II) growth in the hydroponic system. Materials and Methods: In this research, we synthesized Fe-amino acid chelates including Fe-Glycine (Fe-Gly), Fe-Phenylalanine (Fe-Phe), Fe-Tyrosine (Fe-Tyr), Fe-Methionine (Fe-Met), and Fe chitosan chelates in two forms of acidic hydrolyzed chitosan [Fe-C(A.hyd)] and enzymatic hydrolyzed chitosan [Fe-C(E.hyd)] and characterized by FTIR and CHN analyzer. The efficiency of these iron sources for bean (Strategy II) and corn (Strategy I) in hydroponic system was then evaluated. Seeds of bean and corn were washed with distilled water and transplanted into special containers containing coco peat, perlite and vermicompost (1:1:1) at 25 °C for germination and initial growth. The seedlings were transferred to polyethylene plastic lids fitting tightly over 8-L polyethylene containers under controlled conditions in the greenhouse with a light period of 8 hours per day, the temperature of 20 to 25°C and relative humidity of 65 to 75%. The pots were stacked in black color to prevent light reaching the root of the plant and the solution. In each pot, one plant seedling was placed and the basic nutrient solution was prepared in deionized water. The plants were harvested after 8 weeks, their root and shoot were separated and dried after washing with distilled water in an oven at 75 ° C. The dried samples were ground to fine powder to pass through a 20-mesh sieve. The analysis of Fe in samples was performed using atomic absorption spectrophotometer. Result and Discussion: Application of organic chelates of amino acids and chitosan increased the shoot dry matter per plant compared to Fe-EDDHA. Fe content in shoot of corn and bean was highest using Fe-Tyr, Fe-Met and [Fe-C(A.hyd)]. Uptake and accumulation of Fe in roots were observed by using all chelates, but the highest translocation factor was found for the treatments including [Fe-C(A.hyd)] and Fe-Tyr. Translocation factor in bean plants was higher than corn, and around half of Fe in bean plants was translocated from root to shoot. The use of iron chelates in plant growth medium increased the activity of ferric chelates reductase enzymes in bean and corn compared to Fe-EDDHA. However, the mean of this enzyme activity in bean was higher than that in corn. Therefore, the activity of this enzyme can be used as an indicator for determining the iron availability in leaf cells in Strategy I and Strategy II plants. In general, the plants need less energy to absorb Fe when the chelates with a simpler structure are used. Conclusion: The results indicated that using Fe organic chelates in the hydroponic system could supply sufficient amounts of iron for the plant uptake and also improve the root and the shoot growth of bean and corn. Overall, the effect of Fe organic chelates on Fe content of bean and corn shoots was in the following order: Fe- Chi(A.hyd) > Fe-Tyr > Fe-Met > Fe-Gly >. Activity of leaf ferric chelate reductase in bean was higher than that in corn.
S.S. Nurbakhsh; M. Ghobadinia; A. Danesh-Shahraki; mohammad reza Nori Emamzadeie; R. Fatahi
Abstract
Introduction: Nowadays, due to lack of water resources and increasing demand for water, agricultural water planning issues need further consideration. With proper planning and determination of irrigation depth and time, the effects of stress and yield loss on the plants are reduced. Irrigation scheduling ...
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Introduction: Nowadays, due to lack of water resources and increasing demand for water, agricultural water planning issues need further consideration. With proper planning and determination of irrigation depth and time, the effects of stress and yield loss on the plants are reduced. Irrigation scheduling is one of the most important factors in crop’s quality and quantity. The main objective of irrigation scheduling is to control crop’s water conditions in order to achieve its optimum yield level. So irrigation timing is the vital factor on which crop water stress and eventually yield's level are dependent upon. Moreover, irrigation timing is used in irrigation scheduling. The aim of this study was to evaluate the effect of irrigation time on water consumption, water use efficiency and yield of beans.
Materials and Methods: In order to observe the effect of the amount and the time of the irrigation on water consumption, yields rate and water use efficiency, the current research was carried out at the University of Shahrekord during the summer of 2012. The experiment was done as a completely randomized design with 4 repetitions consisting of irrigation time and the amount of irrigation in 4 and 2 levels (at 6, 8, 14 and 18) and (deficit irrigation, full irrigation), respectively. Beans seeds were planted in 32 similar vases with a diameter of 45 cm and height of 60 cm, in each experiment. Treatments were begun after 37 days from planting. Treatments were irrigated when the average moisture in the root zone was equal to the lower border of readily available water of full irrigation. At the end of the experiments, plants were completely harvested. Then the plant’s height, number of branches, numbers of pods per plant, pod and seed weight were measured.
Results and Discussion: Results showed that irrigating at different times during the day influenced water use efficiency, water consumption, seeds yield and number of pods in the bush. The water consumption was affected by irrigation time. Among full irrigation treatments, irrigation at 2 p.m. and 6 a.m. had the highest and lowest water consumption, respectively. The total amount of water used in irrigation at 8 a.m., 2:00 p.m. and 6 p.m. compared to 6:00 a.m. was increased by1.6, 9.5 and 4.1 percent, respectively. The results showed that irrigation at 2:00 p.m., caused a significant reduction in yield. Moreover, water use efficiency in 6 a.m. treatments had increased 18.5 percent more than that of the 2:00 p.m. irrigation treatment. The time of irrigation did not have a meaningful effect on bush height, the number of minor branches, the pod's length. The effect of the amount of irrigation water was meaningful on bush height, number of minor branches, seeds yield, the number of pods in the bush, pods length and seed weight. Seed yield at 8:00 a.m., 2:00 p.m. and 6:00 p.m. treatments has shown 0.29, 17.1 and 7.6 percent decrease in comparison with 6:00 a.m. irrigation treatment, respectively. Moreover, 100-seed weights were significantly affected by the irrigation time. The maximum and minimum weights of 100-seed weights were obtained at 6:00 a.m. and 6:00 p.m. irrigation, respectively. Analysis of variance showed that the number of pods per plant was affected by irrigation time. The maximum number of pods per plant was 101 which belong to the 6:00 a.m. treatment. In this experiment in the case of irrigation at 2:00 p.m., the number of pods per plant was significantly decreased in full and deficit irrigation. The results showed that although the irrigation frequency was the same, irrigation at maximum evapo-transpiration caused the plant to be under stress and the yield was reduced. In other word, it can be said that time of irrigation had no meaningful effect on the appearance and shape of the plant while it was effective in terms of the yield. Overall assessments showed that maximum of the measured features were obtained in the case of 6:00 a.m. treatment.
Conclusion: The results showed that irrigation at different times of the day and the applied water stress, reduced water use efficiency. These caused traits such as plant height; number of branches; number of pods per plant; pod and seed weight to be affected by the irrigation depth. Based on the results of this experiment it can be stated that, when there is no limit of water supply, it is recommended to irrigate in the early morning, before the steep slope of the temperature rise. However, in the situations with water shortage problems, is better to manage the water and the product.
Keywords: Bean, Deficit irrigation, Irrigation time, Water use efficiency
H.R. Motaghian; A. Hosseinpour
Abstract
Change in microorganism activity and chemical properties can be affect on availability and fractionation of Copper (Cu). This research was conducted to investigate the availability and fractionation of Cu in the bean rhizosphere and bulk soils in 10 calcareous soils using rhizobox at greenhouse. Total ...
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Change in microorganism activity and chemical properties can be affect on availability and fractionation of Copper (Cu). This research was conducted to investigate the availability and fractionation of Cu in the bean rhizosphere and bulk soils in 10 calcareous soils using rhizobox at greenhouse. Total organic carbon (TOC), dissolved organic carbon (DOC), microbial biomass carbon (MBC), pH, available Cu (by using 7 chemical extractants) and Cu-fractions were determined in the rhizosphere and bulk soils. The results indicated that in the bean rhizosphere soils, TOC, DOC and MBC increased significantly (p
H.R. Motaghian; A. Hosseinpour
Abstract
Sewage sludge uses as a low coast fertilizer to rectify deficit of elements such as zinc (Zn). A suitable extractant for estimation of bean-available Zn in calcareous soils amended with sewage sludge has not yet been introduced. The aim of this research was to assess several chemical extractants for ...
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Sewage sludge uses as a low coast fertilizer to rectify deficit of elements such as zinc (Zn). A suitable extractant for estimation of bean-available Zn in calcareous soils amended with sewage sludge has not yet been introduced. The aim of this research was to assess several chemical extractants for the estimate of available Zn in sewage sludge-amended calcareous soils. For amended soils, 1% (w/w) of sewage sludge was added to 10 calcareous soils, and the soils (amended and un-amended) were incubated at field capacity for 30 days. At the end of incubation, soils were air-dried and available Zn was determined using 7 chemical extractants (DTPA-TEA, AB-DTPA, Mehlich 1, Mehlich 2, Mehlich 3, 0.1 N HCl and 0.01 M CaCl2). Zinc concentration in shoots, Zn uptake, and shoot dry weight of bean were determined in a pot experiment in amended and un-amended soils. The results show that Mehlich 3 and Mehlich 1 extractants extracted the highest and the lowest concentrations of Zn in both amended and un-amended soils, respectively. Furthermore, all three studied indices and Zn extracted by using different methods increased in amended soils. In addition, results indicated that significant correlations were found between extracted Zn using AB-DTPA, DTPA-TEA and Mehlich 3 and plant indices in un-amended soils. On the contrary, in sewage sludge-amended soils only the correlation between extracted Zn using DTPA-TEA and Mehlich 1 with Zn uptake and shoot dry weight and Mehlich 2 with Zn concentration was significant. The results of this study showed that DTPA-TEA could estimate bean-available Zn in the sewage sludge-amended and –un-amended calcareous soils.
M.A. Khalaj; F. Moshiri; Hadi Asadi Rahmani
Abstract
This study was conducted to evaluate N2-fixing ability of rhizobia strains inoculated with common bean. The experiment was carried out in a randomized complete block design (RCBD) with 13 treatments including 10 Rhizobium isolates, two nitrogen fertilizer levels (200 and 400 kg urea per ha) and one control ...
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This study was conducted to evaluate N2-fixing ability of rhizobia strains inoculated with common bean. The experiment was carried out in a randomized complete block design (RCBD) with 13 treatments including 10 Rhizobium isolates, two nitrogen fertilizer levels (200 and 400 kg urea per ha) and one control (without Nitrogen and rhizobium) in four replications at Esmaeel Abad research station of Qazvin. Plant sampling was done in two growth stages and nodule number and dry weight, shoot dry weight and total N-uptake and seed yield were evaluated. Results of two years field experiment showed that isolate L-75 showed the superior N2-fixing performance and had the highest positive effect on growth factors and could be recommended to use as inoculants strain in Qazvin region. This isolate, produced highest nodule number and dry weight in both years of study. Seed yield production was promoted by 26 and 40% more than control by application of isolate L-75 in the first and second year, respectively. This study showed that inoculation of common bean with effective rhizobia strains resulted in promoting of plant growth and seed yield production and have the benefit to reduce nitrogen fertilizer application in bean cropping.
T. Raiesi; A. Hosseinpur; F. Raiesi
Abstract
The objective of the present study was to evaluate several chemical extractants to estimate available phosphorus (P) for bean growing in calcareous soils from Chaharmahal-Va-Bakhtiari province. The amount of available P was measured by Olsen, Colwell, ammonium bicarbonate-DTPA, 0.01 M calcium chloride, ...
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The objective of the present study was to evaluate several chemical extractants to estimate available phosphorus (P) for bean growing in calcareous soils from Chaharmahal-Va-Bakhtiari province. The amount of available P was measured by Olsen, Colwell, ammonium bicarbonate-DTPA, 0.01 M calcium chloride, BrayІ, ІІ, Mehlich І and ІІ extractants. In addition, soil organic P and total P were determined. A pot experiment consisting of a completely randomized design with three replications was conducted to evaluate the plant performance in association with chemical extractants. After the harvest, dry weight, P concentration and P uptake were determined. The results showed that the amount of extractable P decreased in the following order: Colwell> Mehlich ІІ> Bray ІІ> Olsen> Ammonium bicarbonate -DTPA> Mehlich І> Bray І> 0.01M Chloride calcium. Organic and total P and phosphorus extracted by Colwell, Olsen and Mehlich ІІ methods correlated significantly with plant indices. In addition, the results of stepwise regression analysis showed that the organic P, Colwell and Olsen extractants could explain more variation in the indices of bean plant. The results of this research showed that Colwell, Olsen and MehlichІІ extractants could be used to estimate plant-available P in the studied calcareous soils.
