Document Type : Research Paper
Authors
1
Department of Soil Science, College of Agriculture and Natural Resources of Darab, Shiraz University
2
Department of Soil Science, Faculty of Agriculture and Natural Resources of Darab, Shiraz University, Darab, Iran
3
Department of Agroecology, Faculty of Agriculture and Natural Resources of Darab, Shiraz University, Darab, Iran
Abstract
The balanced absorption of cations in calcareous soils can be affected by the high concentrations of calcium and sodium, and the addition of compounds such as biochars can complicate the cation absorption status. In this research, the effect of adding sheep manure and rice husk biochars produced at 300 and 500°C to a calcareous soil on pH, EC, CEC and soluble and exchangeable K, Ca and Na, and corn growth and absorption of K, Ca, and Na was investigated. Sheep manure biochar had higher pH, electrical conductivity, potassium, calcium, and sodium than rice husk biochar, and their amount increased with the increase in production temperature. Using sheep manure biochar increased the electrical conductivity (by 0.4 dS m-1) and concentration of soluble cations, but rice husk biochar only increased the soluble potassium concentration (by 0.7 mmol L-1). The ratio of calcium to potassium decreased by all biochar applications (from 4.44 to 0.97-1.64). The amount of exchangeable potassium and sodium also increased with the use of biochar (by 5-10 and 0.5-1.5 mmol kg-1, respectively). Corn yield increased from 16 to 160 % with the use of biochars. The application of sheep manure biochar increased the content of cations in the corn shoots compared to rice husk biochar, but decreased the ratio of calcium to potassium, potassium to sodium, and calcium to sodium. In general, rice husk biochars are more effective than sheep manure biochars due to less salinity, more potassium, less sodium, and balanced absorption of cations by plant roots.
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