轮作对土壤肥力及玉米生长发育的影响

黑龙江省西部半干旱区土壤常年风沙侵蚀,土壤质量不断恶化,玉米大豆轮作和玉米连作深翻秸秆还田是当地生产中提高耕地质量、保护农田土壤生态的两种生产模式。利用长期定位试验玉米大豆轮作、玉米深翻秸秆还田种植模式和玉米连作处理对比,研究分析土壤理化性质、玉米生长发育指标和产量,评价两种种植模式技术效果。结果表明,轮作处理显著增加土壤速效氮、速效钾和有机质的含量,显著降低土壤容重10%左右,提高土壤孔隙度8%,对土壤物理结构改善具有良好作用。深翻秸秆还田处理能够显著增加土壤有机质26%～32%,增加土壤速效钾含量,能够显著降低土壤pH值0.4～1.2个单位,提升西部半干旱区地力,改善西部土壤盐碱化。深翻秸秆还田处理更有利于玉米拔节和抽丝期根长生长,有利于茎粗和穗干重的形成,对玉米产量具有显著增产作用。

Effects of Crop Rotation on Soil Fertility and Growth and Development of Maize

In the semi-arid region of western Heilongjiang province, the soil quality has deteriorated due to perennial sand erosion, rotation of maize and soybeans cropping system and deep ploughing and straw returning in maize continuous cropping are two production modes to improve the quality of cultivated land and protect soil ecology in local production. In the long-term positioning experiment, soybean-maize rotation, maize deep ploughing and straw returning planting mode and maize continuous cropping mode were compared. Soil physical and chemical properties, maize growth and development index and yield were studied and analyzed, and the technical effects of the two planting modes were evaluated. The results showed that rotation significantly increased the contents of available nitrogen, available potassium and organic matter, significantly reduced soil bulk density by about 10%, increased soil porosity by 8%, and played a good role in improving soil physical structure. Deep ploughing and straw returning into the field can significantly increase soil organic matter content by 26%-32%, increase soil available potassium content, significantly reduce soil PH value by 0.4-1.2 units, enhance the soil fertility in the western semi-arid region, and improve soil salinization in the western region. Deep ploughing and straw returning into the field is more conducive to root growth at jointing and silking stage, stem diameter and ear dry weight formation, and has a significant yield increase effect on maize.