周年耕作方式对砂姜黑土农田土壤养分及作物产量的影响

Effect of Annual Tillage Practices on Soil Nutrient and Crop Yield in Lime Concretion Black Soil Farmland

为探明适宜于砂姜黑土农田的周年耕作方式,提升砂姜黑土农田地力及作物产量,在冬小麦?夏玉米一年两熟种植制度下,设置多年定位夏玉米季?冬小麦季免耕?旋耕(对照)、免耕?深耕、深松?旋耕、深松?免耕、免耕?免耕5种周年耕作方式田间试验,在定位处理的第4个周年研究耕作方式对砂姜黑土农田土壤有机碳含量、土壤养分及其对作物产量的影响。结果表明,在秸秆全量还田条件下,与试验开始前相比,各处理0~20 cm土层土壤有机碳、全氮、速效钾含量均有所增加。与对照相比,其他处理均增加周年内0~20 cm土层土壤有机碳和全氮含量。免耕?深耕、深松?旋耕、免耕?免耕处理显著增加周年内0~20 cm土层土壤有效磷含量,而深松?免耕处理显著增加冬小麦开花期和收获期0~20 cm土层土壤有效磷含量,整个周年内对照在20~40 cm土层土壤的有效磷含量均最低。深松?免耕处理增加周年内0~20 cm土层土壤速效钾含量,而深松?免耕、免耕?免耕处理20~40 cm土层土壤速效钾含量在夏玉米苗期、大口期、开花期和灌浆期显著高于对照处理。深松?旋耕和深松?免耕处理显著增加夏玉米?冬小麦周年籽粒产量,增幅分别为7.67%和10.21%。综上所述,在秸秆全量还田基础上,深松?旋耕和深松?免耕能够改善土壤有机碳和养分状况,显著提高周年作物产量,可作为黄淮区砂姜黑土农田相对适宜的周年耕作方式。

In order to select the appropriate tillage practices, improving soil nutrient and grain yield of crop grown in lime concretion black soil farmland, the effects of five year winter wheat-summer maize annual tillage practices(no tillage–rotary tillage, no tillage–deep tillage, subsoiling tillage–rotary tillage, subsoiling tillage–no tillage, no tillage–no tillage) on soil organic carbon content, soil nutrient and crop yield were studied in the fourth year. Under the condition of returning total straw to field, compared with the beginning of the experiment, the content of soil organic carbon, total nitrogen and available potassium in 0-20 cm soil layer were increased. Compared with no tillage–rotary tillage, other year treatments increased annual soil organic carbon and total nitrogen contents in 0-20 cm soil layer during the whole growth period. No tillage–deep tillage, subsoiling tillage–rotary tillage, and no tillage–no tillage significantly increase soil available phosphorus contents in 0-20 cm soil layer during the whole growth period, and subsoiling tillage–no tillage significantly increased 0-20 cm soil layer available phosphorus in anthesis and harvestperiod of winter wheat. In 20-40 cm soil layer, soil available phosphorus content of no tillage–rotary tillage was the lowest during the whole growth period. Subsoiling tillage–no tillage increased annual soil available potassium content in 0-20 cm soil layer during the whole growth period. In 20-40 cm soil layer, subsoiling tillage–no tillage and no tillage–no tillage significantly increased soil available potassium content in seedling, trumpeting, anthesis and filling stages of summer maize season. Subsoiling tillage–rotary tillage and subsoiling tillage–no tillage significantly increase annual grain yield by 7.67% and 10.21% respectively. To sum up, subsoiling tillage–rotary tillage and subsoiling tillage–no tillage could improve contents of soil organic carbon and nutrient, and increase grain yield of summer maize and winter wheat under the condition of returning total straw to field. Therefore, subsoiling tillage–rotary tillage and subsoiling tillage–no tillage should be selected as two appropriate tillage practices in lime concretion black soil farmland.