秸秆还田与旋耕对川中土壤物理性状及玉米机播质量的影响

为明确川中丘陵地区紫土小麦-玉米两熟种植模式下机播玉米生产适宜的秸秆还田方式与耕作方式,改善土壤的瘠薄、黏性过大等问题,提高耕层土壤的播种条件、播种质量,达到作物高产的目的,设置秸秆还田旋耕(RTS)、秸秆还田免耕(NTS)、秸秆不还田旋耕(RT)、秸秆不还田免耕(NT)4个处理,研究麦秸还田与旋耕对川中丘区紫色黏土物理性状及机播夏玉米播种质量的影响。结果表明:与秸秆不还田相比,麦秸还田显著增加了拔节期0~10 cm土层土壤毛管孔隙度和免耕处理0~10 cm全生育时期土壤含水量,显著降低出苗率、播种均匀度和幼苗整齐度等指标。与免耕相比,旋耕处理降低了0~10 cm土壤容重、含水量,增加了毛管孔隙度,出苗率提高9.9%,幼苗株高、茎粗、叶面积和干重显著提高。麦秸还田条件下,旋耕处理较免耕处理0~10cm土壤容重降低2.0%~12.1%,出苗率、播种均匀度、每穴苗数、幼苗整齐度显著提高,其中出苗率增加17.9%。玉米出苗率与0~10 cm土壤含水量呈显著正相关,播种均匀度与幼苗整齐度均与0~10 cm土壤容重呈显著负相关。可见,麦秸还田下旋耕处理改善了土壤结构,增加了土壤含水量,更有利于川中丘陵地区小麦-夏玉米种植模式机播玉米质量和幼苗素质的提高。

Effect of straw return and rotary tillage on soil physical properties and me-chanical sowing quality of maize in Central Sichuan

With continuous development of agricultural science and technology and improvement of ecological and environmental awareness in China,rational use of crop straw has become an efficient and sustainable agricultural practice.With the rapid development of winter wheat-summer maize rotation system,concerns have grown about the processing of soil barrenness,wheat straw waste and other cultivation issues.Irrespectively,researches targeting purple clay soils have been limited.Therefore,an experiment was conducted to determine a suitable straw return and tillage method of mechanically sowed maize under wheat-maize double-cropping system in purple soils in hilly areas in Central Sichuan.The study also investigated the problems of soil fertility and viscosity,sowing conditions and plough layer quality for high yields.The experiment consisted of four treatments-rotary tillage with straw return (RTS),none-tillage with straw return (NTS),rotary tillage without straw return (RT) and none-tillage (NT).The aims of the experiment were to study the effects of tillage patterns with wheat straw return on physical properties of purple clay soils,and on quality of mechanically sowed summer maize in hilly areas in Central Sichuan.The results showed that compared with RT,RTS significantly increased capillary porosity in the 0-10 cm soil layer at elongation stage,increased water content in the 0-10 cm soil layer under no-tillage treatment for the entire growth period,and significantly reduced the rate of emergence,and uniformity of mechanical sowing and seedling quality of maize.Compared with NTS,RT reduced soil bulk density and water content in the 0-10 cm layer,but increased capillary porosity,emergence rate,seedling height,stem diameter,leaf area and dry mass of mziae.Under wheat straw return condition,rotary tillage reduced soil bulk density at the 0-10 cm layer by 2.0%-12.1% as compared to no-tillage,significantly improved emergence rate (by 17.9%),plants per hill and uniformity of mechanical sowing and seedling uniformity of maize.Emergence rate of maize was significantly positively correlated with soil water content of the 0-10 cm layer.Both mechanical sowing uniformity and seedlings uniformity were significantly negatively correlated with soil bulk density of the 0-10 cm layer.It was thus clear that rotary tillage with straw return improved soil structure,increased soil water content,benefited the quality of mechanical sowing and quality of seedlings of maize under winter wheat-summer maize cropping pattern in hilly areas in Central Sichuan,China.