NGHIÊN CỨU KHẢ NĂNG SỬ DỤNG THAN SINH HỌC ĐỂ THAY THẾ PHÂN CHUỒNG VÀ PHÂN VÔ CƠ TRONG SẢN XUẤT LÚA

Production and application of biochar is a new technique in agriculture aiming to improve soil fertility and to ensure sustainable production. However, there has been a little systematic research on this issue. A number of authors have studied on potentiality of biochar to increase rice productivity and to improve soil quality, but not concerned to the possibility to alternative organic and inorganic fertilizers in rice production. This article analyzes the effects of biochar on the growth, development, productivity, economic efficiency and the ability to renovate soil quality when using biochar to alternative organic and a part of inorganic fertilizer in rice production. The results showed that when using biochar and organic fertilizer, the rice growth indicators such as plant height, number of tillers/hill, leaf number /hill, leaf area index, the weight of dry matter, effective tillers and grains were signìicantly higher than single use of N, P, K, hence productivity was significantly increased. Level of damage caused by insect and disease pest such as rice leaf folders, rice blast, sheath blight were also reduced. Except for three indicators of soil properties such as Ca++, Mg++ and K+, other important parametters such as soil density, soil porosity, pHKCl, organic carbon OC%, N %, P2O5, K2O, CEC are markedly improved. However, due to the low price of rice, the value-added income from the increase of rice yield are not enough to compensate the extra cost of biochar use, so the net profit and Marginal Benefit Cost Ratio (MBCR) were lower than single use of N, P , K.