Comprehensive evaluation of tillage and straw returning on yearly productivity

An experiment of four treatments (no-tillage + straw mulching, NTS; no-tillage + high stubble remaining, NTH; conventional tillage + straw incorporation, CTS and conventional tillage + no straw returning, CT) was designed to investigate the effects of tillage and straw returning on yearly productivity in a wheat-rice double cropping system for three consecutive years. Results show that wheat yields under NTS and NTH were low, but rice yield increased to some extent, the total yield of rice and wheat was relatively low. Providing additional wheat yield in rice seedling field needed by the latter two treatments, the total yields of rice and wheat under NTS and NTH were higher than those of CTS and CT. technically and economically, NTS could reduce the cost, increase the total income by about RMB1874.8 per hm2, about 18% raising rate, so increase the yearly economic productivity. Compared with CT, CTS achieved a higher yield and productivity. Viewing the effects of CTS on soil fertility and the decreased fertilizer usage, the efficiency was very obvious. Considering yield, quality and sustainable development, a comprehensive appraisal system was proposed to give a fair evaluation of yearly productivity of rice and wheat under different cropping systems. Four tillage and cultivation methods were evaluated according to this evaluation system. The appraisal results show that NTS won the highest score due to its highest yearly productivity. NTH, CTS took the 2nd and 3rd places. CT was the last.