免耕套种与秸秆还田对农田生态环境及小麦生长的影响

1　引　　言免耕作为低耗持续农业生产和保护性耕作的一项重要手段,越来越受到国内外学者的重视.在国外,免耕最早是20世纪30年代为防治土壤风蚀而采取的措施,60年代得到迅速发展,且随着研究的不断深入,免耕的作用逐渐扩大10,18].我国自70年代后期开始免耕的系统研究,在免耕和秸秆覆盖对土壤理化性质、微生物区系及生态环境的影响等方面都有不少报道2,11,16,17,23].秸秆还田在提高土壤肥力,增加作物产量等方面已被许多研究所证实3,5～8,12,13,19～21].随着社会和生产的发展,秸秆还田的方式,方法和数量都在不断变化,尤其是部分地区禁烧秸秆…

Effects of no-tillage plus inter-planting and remaining straw on the field on cropland eco-environment and wheat growth

The studies showed that under no-tillage plus inter-planting rice and wheat, the height of rice stubble remained on the field significantly affected light transmission rate, with an optimal height of 20-30 cm. No-tillage and straw-remaining decreased soil temperature at noon in sunny days, but slightly increased it in the morning and evening, led to a less diurnal difference of soil temperature. The average diurnal soil temperature under no-tillage was higher in cloudy but lower in sunny days. Under no-tillage and straw-remaining, both the bulk density and the penetration resistance of topsoil increased, but no apparent adverse effect of them was observed on wheat growth. Under no-tillage, soil water content was higher under drought condition, and soil permeability after irrigation was better, which was propitious to the wheat growth. Straw-remaining significantly inhibited weeds, but led to the decrease of basic seedlings and enhanced the damage of freezing. Under no-tillage plus inter-planting, the individuals of effective ears decreased, while the kilo-grain weight increased. The grain yield was slightly but not significantly low under no-tillage plus inter-planting.