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hassan osooli; Ahmad Karimi; Hossin Shirani
Abstract
The use of organic waste in the form of biochar in order to ameliorate soil is a novel approach in the management of organic waste. In previous studies, researchers mostly focused on the amount of biochar that was added to the soil. However, the aim of this study was to investigate the characteristics ...
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The use of organic waste in the form of biochar in order to ameliorate soil is a novel approach in the management of organic waste. In previous studies, researchers mostly focused on the amount of biochar that was added to the soil. However, the aim of this study was to investigate the characteristics of biochars prepared from different feedstock (wheat straw, vermicompost and apricot firewood) and the interaction effects of amounts and particle sizes of biochars on yield and water use efficiency (WUE) of winter wheat. In a factorial experiment with a randomized complete block design with three replications, the effects of these three biochars in the amount of 0.5% (R1), 1.5% (R2) and 3% (R3) with a particle size of ≤0.5 (S1), 0.5-1 (S2) and 1-2 (S3) mm were evaluated in two consecutive cropping years. The studied biochar were added to the soil only in the first year to a depth of 0-15 cm. A control plot was considered in each replication. The interactions of experimental factors (except interaction effect of year and biochar amount) on yield and WUE were significant. Comparison of average yield and WUE in each type of biochar showed that, in the first and second year, wheat straw biochar treatment of R3 S2 had the highest yield (5,200 kg ha-1 and 6664.3 kg ha-1, respectively) and WUE (1.6 kg m-3 and 2.1 kg m-3, respectively). In the first year, in vermicompost biochar treatments, the highest yield (4517.7 kg ha-1) and WUE (1.4 kg m-3) were observed in the R2 S3. In the same year, in apricot wood biochar, treatment R3 S3 had the highest yield (3871.7 kg ha-1) and WUE (1.2 kg m-3). In the second year, in vermicompost treatments, the highest yield (6615.7 kg ha-1) and WUE (2.04 kg m-3) was observed in the R3 S2 and, in the same year, in apricot wood biochar treatments, the highest yield (5263.7 kg ha-1) and WUE (1.6 kg m-3) was observed in the R2 S3. The highest yield and WUE (in the two years) was observed in wheat straw biochar with the R3 S2. These results showed that in addition to the type of biochar, the interaction of the amount and size of biochar particles had a decisive effect on increasing the yield and water use efficiency of wheat.
e g; a m; a k
Abstract
Drought and its resulting stress is one of the most important common environmental stresses that limit agricultural productions. In order to evaluate the effect of cattle manure biochar on the growth, yield, and water use efficiency of spinach at different soil moisture status, a factorial completely ...
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Drought and its resulting stress is one of the most important common environmental stresses that limit agricultural productions. In order to evaluate the effect of cattle manure biochar on the growth, yield, and water use efficiency of spinach at different soil moisture status, a factorial completely randomized design with 3 replications was conducted under greenhouse conditions during October 2014 to January 2015. Treatments consisted of four biochar levels (0, 1.25, 2.5 and 5% wt of initial soil) and three soil moisture levels (FC (without stress), 0.7FC, and 0.55FC). To compensate the water losses via evapotranspiration, the pots were weighted every day and water stress was imposed by adding the water required in each treatment. Total water consumption during the growing season was also determined. Results indicated that application of both soil water stress levels resulted in significant reduction in leaf area, stomatal conductance, water consumption, and fresh and dry weight as compared to those of the controls (without water stress and biochar application). The greenness index significantly increased by 14%, 14%, and 11 % as compared to that of the control when soil moisture level of 0.55 FC was applied at the first, second, and third growth stages (40, 55 and 70 days after planting), respectively. Application of biochar also significantly increased greenness index, leaf area, and stomatal conductance as compared to that of the control. Soil moisture stress up to 0.7FC decreased the plant water consumption; however, it did not affect the water use efficiency, significantly; while water stress level of 0.55 FC decreased water use efficiency significantly. In general, application of 1.25 biochar (25 ton/ha) as compared to the control decreased the negative effects of water stress on plant (reducing leaf area, fresh and dry weight, etc.) and improved plant growth indices and increased the growth of plant at all of the applied water stress levels. Therefore, in order to reduce water consumption and improve the growth and yield of plants, biochar application, especially under drought stress conditions or in greenhouse conditions, is recommended. Meanwhile, performing such an experiment under field conditions is also suggested.