THE IMPROVEMENT OF ECOLOGICAL RECYCLE IN SOIL BY OPTIMIZING FERTILIZER COMBINATION IN PADDY ECOSYSTEM
优化肥料结构促进稻田土壤生态良性循环

Two-period location experiments on soil fertility were conducted respectively in Fuzhou and Putian in continous 16 cropping seasons from 1985 to 1992. The results show that the combining applications of urea with Azolia, green manure, barnyard, manure and rice straw separately provided an active effect on physical character, carbon/nitrogen balance, microflora, enzymatic activity and nutrition-providing apacity of soil. The averaged annual grain yield per hm2 of above combinations was/10. 7%, 11. 4%, 9. 6 % and 6. 5 % higher than that in check plot where only equivalent nitrogen was applied. The combining application of inorganic fertilizer with organic manure achieved significant benefits in economy and soil ecological recycle.