Scheme of Nitrogen Reasonable Fertilization in Mulberry Gardens of Sichuan Hilly Areas

摘要

Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to establish utility functions of ap-plied N in mulberry gardens with different production purposes and to provide schemes of rational N fertilization. The results indicated that yield of mulberry leaf and content and yield of active nutritional substances in the leaves would be reduced either by insufficient or excessive N quantity. In addition, 240 kg/hm^2 of applied N significantly improved active nutritional substances in leaf and 360 kg/hm^2 of applied N significantly improved yields of mulberry leaf and active nutritional sub-stances. Therefore, utility functions of applied N quantity with leaf yield, DNJ content and yield were established accordingly. The optimal N quantity in mulberry gardens for sericulture is recommended 360 kg/hm^2 and the optimal N quantities in mulberry gardens for increase of yield and content of DNJ are 299.56 and 294.72 kg/hm^2, respectively.