中亚热带稻田不同耕作栽培和施肥模式对土壤肥力的影响

Effects of Different Tillage, Straw Returning and Transplanting Methods on Paddy Soil Fertility in Middle Subtropical Region

水稻轻型化栽培技术是我国南方双季稻区发展的重要方向。为深入比较和评估不同轻型栽培方式对土壤肥力的影响，本研究于2008年开始在中亚热带设置了耕作方式（深翻耕和浅旋耕）、秸秆还田与否和栽培方式（直播、抛秧和插秧）的田间试验，系统分析了水稻产量、土壤有机质和氮磷钾养分的变化规律。研究结果显示：耕作和栽培方式不会显著影响水稻产量变化；但秸秆还田后水稻产量比不还田增加1．6％～7．6％。在土壤培肥方面，不同栽培方式下土壤有机质和养分的变异较大，而浅旋耕和秸秆还田则能显著提高耕层土壤的有机质和速效养分。与深翻耕相比，浅旋耕方式下土壤有机质、碱解氮、有效磷、速效钾含量分别提高了5．1％～11．5％、2．2％～10．4％、5．5％～29．2％、7．8％～22．1％。与秸秆不还田相比，秸秆还田处理的土壤有机质、碱解氮、有效磷、速效钾含量分别增加了2．7％～6．6％、3．4％～5．5％、2．2％～5．O％、16．3％～49．3％。因此，浅旋耕和秸秆还田可以显著提高土壤肥力，且水稻产量稳定，在中亚热带地区具有很大的推广前景。

To evaluate the effects of light cultural techniques on soil fertility, a field experiment was conducted in the northeast of Jiangxi from 2008, which including deep and shallow tillage, with or without straw returning and direct seeding （DS）, throwing seeding （TS） and transplantation （TP）. The results showed that straw returning could increase grain yield of early and late rice by 1.6% to 7.6% compared without straw returning. The shallow tillage and straw returning could improve soil organic matter and available nutrient contents significantly. Compared with deep tillage, soil organic matter, alkali-hydrolysable nitrogen, available phosphorus and potassium of shallow tillage were increased by 5.1%-11.5%, 2.2%-10.4%, 5.5%-29.2% and 7.8%- 22.1%, respectively. Compared with the treatments without straw returning, soil organic matter, alkali-hydrolysable nitrogen, available phosphorus and available potassium were increased by 2.7%-6.6%, 3.4%-5.5%, 2.2%-5.0% and 16.3%-49.3% respectively in the treatments with straw returning. This indicates that shallow tillage and straw returning could improve paddy soil fertility and grain yield in the middle subtropical region.