NGHIÊN CỨU HIỆU QUẢ SỬ DỤNG PHÂN VIÊN NÉN DÚI SÂU NK CHO CÂY LÚA Ở THANH HÓA

To improve the efficiency of fertilizer, vaious NPK and deep thrust-tablet fertilizers have been developed to meet the nutritional requirements of each crop and growth stages. This article introduces new research findings in Thanh Hoa on usability of NK tablets to replace nitrogen, potassium in rice production, contributing to improving the efficiency of fertilizer, improving crop productivity and economic efficiency for the slope land area of Thanh Hoa. It was indicated that in both low land and terraced field, the use of NK tablet provided absolutely no adverse effects, but also significantly improves rice growth and reproductive indicators such as plant height, number of effective tillers, leaf area index, dry matter weight, number of spiklets/hill and number of spiklets/m2 , thereby increasing crop productivity and yield. When using NK tablet fertilizer, the infection of major insects and diseases such as Brown plant hopper, sheath blight is significantly reduced as compared with conventional application of manure + inorganic fertilizers (N, P, K). The infection of other pests such as rice stem borer, leaf folders, blast, blight is not quite clear. The cost for NK tablet roughly equivalent to the single N, P, K use, but thank to the increase of crop yield, it can bring higher net benifit and Marginal Benefit Cost Ratio (MBCR). However, using NK tablet without manure provided lower crop yield and economic efficiency than traditional farming (manure + N, P, K). The study also showed that MBCR in all cases of using NK tablet is higher than 2. It means that NK tablet fertilizer should be encouraged to apply.