gholamreza Adim; Elham Malekzadeh; Esmael Dordipour; Farshad Kiani; Hassan Mokhtarpour; seraj Moazzemi
Abstract
Introduction In recent years, ensuring the continuous and sustainable production of healthy food products along with environmental protection and paying attention to agricultural economic and environmental problems is very important. Although the use of chemical fertilizers has a high yield of plants, ...
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Introduction In recent years, ensuring the continuous and sustainable production of healthy food products along with environmental protection and paying attention to agricultural economic and environmental problems is very important. Although the use of chemical fertilizers has a high yield of plants, its destructive effects in the long-term are known on the soil biological, physical and chemical properties and environmental pollution. Therefore, a strategy must be considered that can improve soil health and quality as well as produce a high plant yield. Organic manures increase the growth, yield and quality of plants by improving soil conditions and the balance of essential elements. An integrated plant nutrition management system by reducing the use of chemical fertilizers is known as one of the ways to achieve the expected yield and meanwhile, minimize the adverse environmental effects of chemical fertilizers in the world.Materials and Methods The objective of this study was to evaluate the effect of single and combined use of chemical fertilizer (urea, triple superphosphate, potassium sulfate as NPK) with organic and biological fertilizers on the yield and yield components of transplanted canola (Brassica napus L.). Experiment was conducted in a randomized complete block design with six treatments and three replications (18 experimental units) in the 2019-2020 crop year at the Iraqi Agricultural Research Station in Gorgan, Iran. Treatments included: 1) Control (without fertilizer, T1), 2) Chemical fertilizer (T2), 3) Poultry manure (T3), 4) Compost (T4), 5) 50% Chemical fertilizer+ 50% Poultry manure+ 50% Compost (T5), 6) 50% Chemical fertilizer+ 50% Poultry manure+ 50% Compost+ Biofarm-1 biofertilizer (T6). Chemical fertilizer was applied based on soil test including nitrogen equivalent to 250 kg/ha urea was added in three stages during planting, stem elongation, before flowering; phosphorus equivalent to 150 kg/ha of triple super phosphate; potassium equivalent to 50 kg/ha of potassium sulfate, respectively. Organic fertilizers were calculated based on their total nitrogen contents and the equivalent of pure nitrogen recommended based on the soil test for chemical fertilizer and by assuming 50% mineralization rate of organic fertilizers in the soil. Biofertilizer was applied as seed inoculation plus spraying on the plant base in two stages of 4 to 8 leaves and stem elongation. Chlorophyll index was measured in the middle of the flowering stage by using SPAD. After physiological maturity, yield and yield components including pods per plant, numbers of seeds per pod, pod length, 1000-seed weight, seed yield, protein and oil contents of grain were recorded. Results and Discussion The results showed that the effect of fertilizer treatments was significant on yield and yield components (p <0.01). The highest 1000-seed weight, grain yield, protein content of the seed, number of seeds per pod, pod length and pods per plant were recorded in the treatment of 50% chemical fertilizer+ 50% Poultry manure+ 50% Compost+ Biofertilizer (T6) which increased by 21.9%, 43.7%, 33.8%, 29.2%, 37.2% and 37.6%, respectively, in compared to the control treatment (with the lowest values). The pods per plant, 1000-seed weight and grain yield were not significantly different between the combined treatments of chemical fertilizer+bio-organic fertilizers (T6) and integrated use of chemical and organic (T5) fertilizers (p <0.05). The control treatment (T1) by 2248.37 Kg/ha of grain yield (the minimum amount) decreased by 43.7% and 38.3% compared to T6 and T5 treatments, respectively. The chemical treatment (T2) and integrated application of chemical fertilizer+ bio-organic fertilizers (T6) showed the most positive effect on the chlorophyll index compared to other fertilizer and control treatments (with the lowest index, 43.66). Chlorophyll index in the T2 and T6 treatments increased by 35.6% and 33.7% compared to the control treatment (T1), respectively. The treated plants by alone use of organic fertilizers (T3 and T4) without notable difference produced the highest grain oil (by an average of 45.73%) which increased by 6.6% compared to the chemical fertilizer (T2) and control (T1) treatments by an average of 42.7%.Conclusion Combined use of chemical fertilizer with bio-organic fertilizers had the most positive effect on yield and yield components, and often showed significant difference with the single application of chemical and organic fertilizer treatments (T2, T3 and T4). Therefore, the combination use of chemical and bio-organic fertilizers is a better option to increase the yield and yield components of transplanted canola than the single use of chemical fertilizers. The highest pods per plant, pod length, number of seeds per pod, chlorophyll index, protein content, chlorophyll, 1000-seed weight, and grain yield were related to the integrated application of chemical fertilizer with bio-organic fertilizers (T6 and T5), so it can be inferred that the use of a mixture of organic, biological and chemical fertilizers is an effective approach to reduce the using of chemical fertilizers and their destructive environmental effects, as well as increase the yield of transplanted rapeseed
Seyed Ameneh Ghoreishi Amiri; Mojtaba Barani motlagh; Esmaeil Dordipour
Abstract
Introduction: Focusing on population and industrial centers in the different areas has caused the formation of a huge volume of sewage which their treatment (refining) has led to produces a larger volume of sludge so that without any attention to find out the best disposal way, has created various environmental ...
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Introduction: Focusing on population and industrial centers in the different areas has caused the formation of a huge volume of sewage which their treatment (refining) has led to produces a larger volume of sludge so that without any attention to find out the best disposal way, has created various environmental difficulties. One of the economic and efficient ways to use sewage sludge is utilizing them in agriculture. Sewage sludge, due to its large amount of nutrients and organic matters and being less expensive, nowadays it is widely used as a fertilizer and/or amendment of soil physical and chemical properties. In the present study, the effect of different levels of industrial sewage sludge application on the bioavailability and distribution of various forms of iron in spinach plant, Shahr Reza cultivar was evaluated.Materials and Methods: Soil was collected from 0-30 cm depth around Aq Qala industrial town. After air drying, the soil was passed a 2 mm sieve and its physical and chemical properties measured. For this purpose, a completely randomized design with different levels of industrial wastewater sludge (0, 22.5, 45, 90, 180 and 360 ton/ha) was conducted in the form of a pot experiment with 4 replicates in greenhouse of research center of Gorgan Agricultural and Natural Resources Research. The experimental units were pots of 7 kg soil. Then, 20 seeds per pot were planted at 2 cm depth of soil and after two weeks of emergence, the number of shrubs was reduced to 5 plants per pot. Irrigation and weeding were done manually. After the end of the growth period (90 days), the plant samples were digested by dry-digesting method. The concentration of iron in the samples was determined by atomic absorption device (AAS-Unicam-919). Immediately after harvesting, the soil of pots was air-dried and passed through a 2 mm sieve. Then the amount of soil extractable iron by DTPA was read by the atomic absorption device. In addition, Tessier et al. (1979) method was used to investigate the distribution of different forms of iron after sludge application. Statistical analysis of the test data was performed using SAS software and LSD test (5%) was used to compare the means. Also, Graphs were plotted using Excel software.Results and Discussion: The results showed that concentration of iron in the soil and aerial parts of spinach was significantly affected by the sewage sludge application. The highest dry weight of the spinach aerial part with an average of 5.89 g/plant was related to 90 tons/ha sludge treatment and the lowest with an average of 1.07 g/plant was related to the control treatment. Although the application of sludge at high levels such as 180 and 360 t. ha-1 led to a reduction spinach yield, this seems to be due to sludge effects such as the presence of heavy metals, disturbance of soil C/N equilibrium, and especially increase soil salinity. The concentration of iron in spinach aerial parts increased linearly in 22.5, 45, 90, 180, 360 ton/ha sludge treatments, which had an increase of 3.19, 5.16, 12.04, 26.06 and 52.76 percent compared to the control treatment, respectively, while the highest amount of iron uptake with an average of 767.47 mg/kg dry matter obtained in 90 ton/ha sludge treatment and the lowest amount with an average of 124.43 mg/kg dry matter was related to control treatment. The average of iron uptake in the aerial parts of spinach in 180 and 360 t/ha sludge treatments, respectively, was 735.93 and 341.08 mg/kg dry matter, which was 4.28% and 125% lower than 90 t/ha treatment, respectively. The results also showed that application of 360 t/ha sewage sludge increased 73.48% DTPA extractable iron compared to the control treatment. The results of iron fractionation showed that the amounts of all iron components in the soil (except iron and manganese oxides) increased by application of sewage sludge. In the control soil, different iron components were as follows: exchangeable> carbonate> organic> iron and manganese oxides> residual. By applying treatments, the order did not change except that after application of treatments, in all components of iron (except iron and manganese oxides) showed an increase in the amount of each component compared to the control treatment. The correlation between the chemical forms of iron with DTPA-extractable iron and iron concentration of spinach showed that between iron concentration in spinach and extractable iron with DTPA (r= 0.93), exchangeable iron (r= 0.95) and iron bound to the organic fraction (r= 0.98) had a significant and positive correlation at the 1% level and with iron bond to iron and manganese oxides (r= 0.98) had a significant and negative correlation at 1% level which may indicate the role of these forms of iron (DTPA-extractable iron, exchangeable iron and organic-bound iron) in the nutrition of spinach (Spinacia oleracea L.). Increased Fe concentration in plant organs by sewage sludge application may be due to increased concentration of elements in soil and consequently higher uptake of this element by plant.Conclusion: In general, it can be concluded that the application of sewage sludge in high amounts of 180 and 360 ton/ha with the effect on physical and chemical properties of soils such as disturbance of nutrient balance and increasing soil salinity causes a decrease in plant dry weight and the ability of iron uptake in the spinach plant. However, sewage sludge application provides nutrients for plant growth and reduces the economic cost of disposal. However, it is recommended to determine the threshold of toxicity and salinity before application of sewage sludge depending on soil, plant and environmental conditions. More extensive research is also needed to standardize the method and relative amounts of use of this organic amendment.
T. Nazari; M. Baranimotlgh; E. Dordipour; R. Ghorbani nasrabadi; S. Sefidgar Shahkolaee
Abstract
Introduction One of the most important needs in crop planning is the evaluation of different systems of plant nutrition. plant nutrition in a correct way can preserve the environment and increase efficiency of agricultural inputs. Humic acid contains many nutrients that increase the soil fertility and ...
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Introduction One of the most important needs in crop planning is the evaluation of different systems of plant nutrition. plant nutrition in a correct way can preserve the environment and increase efficiency of agricultural inputs. Humic acid contains many nutrients that increase the soil fertility and soil organic matter content and thus affect plant growth and yield. In the present study, the effect of soil and foliar application as well as fertigation application of humic acid on iron and phosphorous availability of canola (Hyola 308) was evaluated. Materials and Methods The soil was air-dried and ground to pass through a 2-mm sieve and then was analyzed to determine soil physical and chemical properties using standard methods. A greenhouse experiment was carried out with 10 treatments in four replications. Treatments include humic acid soil application at three levels (1, 2 and 4 g.kg-1 soil), foliar application at three levels (0.1, 0.2 and 0.4%) and three fertigation levels (1000, 2000 and 4000 mg L-1) and control). Soil application in the form of humic acid powder and in cropping time based on the soil weight of the pots and for spraying and use along with irrigation water, each of the spraying and together with irrigation water levels is divided into three equal parts and in three stages (plant establishment, stem elongation and flowering). At the end of growth period (for 139 days), vegetative growth indices were determined and then plants were harvested and stem and leaves were separated. Phosphorous content in plant extracts was measured by molybdate vanadate method (yellow method) and iron concentration in the samples was determined by atomic absorption (AAS-Unicam-919). Statistical analysis was conducted via SAS software and mean comparisons carried out by LSD test at 5% probability level. Results and Discussion Results show that the application methods and the different levels of humic acid had significant impacts (p < 0.01) on the all parameters but they had no significant effects on the numbers of leaves. The maximum leaf fresh weight was 4.34 gr per plant which obtained water irrigated treatments with 2000 mg/lit. However, there was no significant difference between water irrigation with 4000 and 2000 mg/lit humic acid concentrations. Besides, maximum leaf dry weight was 0.37 gr in the plant that was water irrigated with 4000 mg/lit, however there was no significant difference between water irrigation with 4000 and 2000 mg/lit humic acid concentrations. Also, the maximum stem dry and fresh weight was 5.92 and 1.53 gr which observed in water irrigated with 2000 mg/lit. The application methods and the different levels of humic acid had significant impact (p<0.01) on the content and absorption of Fe and P excluding the Fe content in the root. The maximum Fe content in stem and seed were 321.25 and 85 mg/kg was observed in the treatment of humic acid with water irrigation of 2000 mg/lit. Also, in the treatment of spraying with 0.4 % of humic acid, the maximum of Fe concentration (245.46 mg/kg) was obtained. The humic acid molecules can pass from the cell membranes and cause iron reduction in the Apoplast and increase the availability of Fe. Because of the reduction effect of humic acid on the availability and accumulation of Fe in the plant tissue, increasing in the Fe absorption with humic acid treatment is observed. The increase in the accumulation of Fe by humic material might be due to the releasing phenolic material in the root rhizosphere. The maximum P concentration in the leaf, stem and seed were 0.40, 0.72 and 0.897 respectively that was observed in the treatment of water irrigation with 2000 mg/lit with humic acid. Due to the availability of phosphorus and other nutrients for wheat, humic acid increases the plant yield in the reproductive stage of seeding. Conclusion Results of the study show that humic acid can ameliorate the negative effect of a large amount of phosphorus on iron availability. In fact, humic acid, due to providing nutritional balance for the plant, prevents negative effects caused by the high amounts of specific elements such as phosphorus. Also, the results showed that all three humic acid application methods increased vegetative growth parameters, and iron and phosphate availability for canola plant compared to control. But in general, 2000 mg/L acid humic with irrigation water was more effective than two methods of soil and foliar application.
Soil Chemistry and Pollution
Somayeh Sefidgar shahkolaie; Mojtaba Baranimotlagh; Farhad Khormali; Esmael Dordipour
Abstract
Introduction At present, contamination of water and soil resources is an important environmental challenge. Therefore, decontamination of such is a prerequirement for using these resources. Cadmium (Cd) and lead (Pb) often coexist in contaminated soils and there is currently no effective means for their ...
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Introduction At present, contamination of water and soil resources is an important environmental challenge. Therefore, decontamination of such is a prerequirement for using these resources. Cadmium (Cd) and lead (Pb) often coexist in contaminated soils and there is currently no effective means for their concurrent removal. Concerns about their mobility and bioavailability have increased because of food safety, potential health risks and its detrimental effects on the ecosystems. The stabilization/solidification is a cost effective remediation method that prevents spreading of heavy metals in soil and water resources. In this process, contaminated soil reacts with amendments such as organic and liming materials to form low soluble or non-soluble stable materials. The objective of this study was to evaluate the effect of several low cost amendments on Cd and Pb stabilization by a sequential extraction method. Materials and Methods In this research, in order to investigate the effect of organic amendments (biochar 640°C, and biochar 420°C) and inorganic amendments (Pumice, Leca, Zeolite, and Bentonite) on Pb and Cd stabilization in a contaminated soil, an incubation experiment was carried out. One kilogram of each amended soil and the control soil were packed into respective pots. Soils were amended in the laboratory using biochar 640 (BI1), biochar 420 (BI2) bentonite (BE), pumice (P), leca (LE), and zeolite (Z). A control treatment (C) without adding amendment was also prepared. The amendment materials were applied at 1 and 5 percent wt. Each treatment was performed in three replicates and the samples were incubated in the dark at 14°C for 6 months. At the end of the incubation time, the potential bioavailability of Cd in non-amended and amended soils was evaluated by extraction with DTPA and ethylenediamine tetraacetic acid (EDTA). Total Cd (CdT) and Pb (PbT) was extracted by aqua regia (HNO3 + HCl) extraction. The chemical fractions of Cd and Pb were determined by a sequential extraction method which is a five-step chemical fractionation based on the work of Tessier et al. (1979). All statistical analyses were performed using SAS software. Means of different treatments were compared using LSD (P ≤0.05) test. Results and Discussion The results indicated that the additions of amendments to soils reduced the concentration of DTPA and EDTA-extracted Pb and Cd. The smallest concentration of Pb-extracted DTPA and EDTA was observed in organic amendments treated soil (biochar 640°C, and biochar 420°C) and treated with 5% biochar 640°C, respectively. The high sorbent capacity of the BI used in this study could be due to its high pH, high content of organic carbon and cation exchange capacity (CEC). The highest decreasing rate of DTPA and EDTA-extractable of Cd was observed in treated with 5% pumice and zeolite, respectively. Application of the amendments (except for 1% LE) decreased exchangeable fraction (F1) of Pb compared to the non-amended soil. Also, the amendments (except for 1% P, Z and BE) decreased exchangeable fraction (F1) of Cd compared to the non-amended soil. Although the biochar 640 (5%) showed the highest decreasing rate of exchangeable fraction (F1) of Pb and Cd, they increased the oxide (F3) and organic (F4) fractions, which might be due to its rich O-containing functional groups and high alkalinity leading to an increase in the binding of Cd and Pb to organic compounds and mineral oxides. Conclusion Results indicated that application of amendments was successful in lowering the potential bioavailability of Pb and Cd soils. The 5% biochar 640 treatment had the greatest decrease in extractable Pb. Also, the 5% zeolite and pumice treatment had the greatest decrease in extractable Cd. Application of BI resulted in a significant decrease in both Pb and Cd exchangeable fraction (F1). This reduction in the exchangeable fraction (F1) of Cd and Pb in the soil was due to an increase in the fraction of heavy metals bound to the soil organic matter (F4) oxides (F3) after BI addition. Enhanced precipitation or co-precipitation and complexation of metals with amendments led to the reduction of the solubility of the metals. The P, LE, BE, and Z altered the exchangeable fraction (F1) of Cd and Pb to the oxide fraction (F3) and the carbonate fraction (F3), respectively. Application of BI amendment causes the highest decreasing rate of solubility Cd and Pb, suggesting this as the suitable amendment for the remediation of Cd and Pb in contaminated soils.
S. Baghbani; M. Baranimotlgh; E. Dordipour
