The Effects Of Different Tillage And Rice-Straw Returning On The Rice Growth And Soil Fertility

To study the effects of different tillage and rice-straw returning on soil fertility,soil microorganism and rice yields under the various cultivating condition, the fieldexperiment of 0, 33%, 67% and 100% rice-straw returning treatments underplowing and no-tillage were conducted. The results indicates:1 Rice-straw returning could increase the content of soil total N,P and K. Themaximum total soil N content in booting stage, full-heading stage, milking stage andcomplete maturing stage are the treatments of 67% rice-straw returning with plowing,67% rice-straw returning with plowing, 67% rice-straw returning with no-tillage and100% rice-straw returning with no-tillage respectively. The maximum total soil Pcontent in booting stage and milking stage are the treatments of 100% rice-strawreturning with plowing and 33% rice-straw returning with plowing respectively, and67% rice-straw returning with plowing in full-heading stage and complete maturingstage. The maximum total soil K content in booting stage, full-heading stage andcomplete maturing stage are the treatments of 67% dee-straw returning with plowingand 33% rice-straw returning with plowing in milking stage.2 Rice-straw returning increased the content of soil available N, P and K. Themaximum available soil available N content in booting stage and full-heading stageare the treatments of 100% rice-straw returning with no-tillage and 67% rice-strawreturning with no-tillage respectively, and 33% rice-straw returning with no-tillagewas the highest in milking stage and complete maturing stage. The highest effective Pcontent in booting stage is the treatment of 33% rice-straw returning with no-tillage,and 67% rice-straw returning with no-tillage in full-heading stage, milking stage andcomplete maturing stage. The variation tendency of soil available K content wassimilar to P.3 Rice-straw returning increased the content of soil microbial and soil microbialactivity. The maximum of soil bacteria in maximum tillering stage, full-heading stage,milking stage, complete maturing stage are the treatments of 67% rice-straw returningwith no-tillage, 67% rice-straw returning with plowing, 67% rice-straw returning withplowing and 100% rice-straw returning with plowing respectively. The maximum soilfungi in maximum tillering stage, full-heading stage, milking stage are the treatmentsof 33% rice-straw returning with plowing, and 100% flee-straw returning withno-tillage was the highest in complete maturing stage. The highest actinomycesmilking stage and complete maturing stage are the treatments of 33% rice-strawreturning with plowing and 67% dee-straw returning with plowing respectively, and57% rice-straw returning with no-tillage was the highest in maximum tillering stageand full-heading stage. The highest microbial activity in maximum tillering stage,ull-heading stage, milking stage, complete maturing stage are the treatments of 100%ce-straw returning with no-tillage,100% rice-straw returning with plowing, 33%ce-straw returning with no-tillage, 33% rice-straw returning with plowing. 4 In both tillage and no-tillage methods, rice yield of the treatments withflee-straw returning were higher than that of CK, as well as the effective paniclenumber, spikelet number per panicle, setting rate and 1000-grain weigh.5 In both tillage and no-tillage farming methods, the dry matter accumulation ofthe treatments with rice-straw returning was higher than that of CK in differentgrowth periods of flee.