关键词: 小麦, 小麦, 种植模式, SPAD值, 净光合速率Pn, 产量, 收益

Abstract: Maize straw was returned to field 6 times continuously and 3 times discontinuously, the turnover amounts were 15000 and 7500 kg/hm2. The differences of soil nutrient contents and physicochemical properties between maize straw turnover and non-straw turnover, continuous and discontinuous turnover, and different straw turnover amounts were investigated to promote the effect of maize straw turnover. The results showed that: (1) compared with CK (non-straw turnover), straw turnover could increase the content of soil organic matter, available N, available P and available K, especially the available N and available K content increased obviously, while soil bulk density decreased; (2) continuous turnover treatment increased soil organic matter, available N, available P and available K by 38.26% , 18.7 3% , 51.73% and 18.74% respectively compared with that of discontinuous turnover treatment, and soil bulk density decreased by 3.87% ; the improving effect of continuous straw turnover on soil nutrient content and physicochemical properties was better than that of discontinuous straw turnover; (3) the content of soil organic matter, available N, available P, available K and total porosity of large turnover amount (15000 kg/hm2) increased by 18.25%, 37.40%, 35.45%, 19.65% and 8.44% compared with that of small turnover amount (7500 kg/hm2), while the soil bulk density decreased by 76.11%. The increase of turnover amount had more obvious effect on the improvement of soil nutrient and physicochemical properties.