论文部分内容阅读
保护性耕作(conservationtillage)能够减少水土流失、提高耕地产量,是一类具有生态保护意义的持续性农业耕作形式。2002年至2004年在定西旱地农业地区进行了保护性耕作条件下旱地农田春小麦豌豆双序列轮作土壤水分动态及产量效应的试验研究,结果表明:保护性耕作能够显著改善0～200cm土层土壤贮水量及含水量,随着降水量的增多土壤对降水的保蓄能力增强。在降水较少年份免耕秸秆覆盖的这种作用表现突出,而在降水充沛的年份免耕地膜覆盖则更具优势。耕层土壤水分因受降水等因素的影响而变化剧烈,耕层以下土壤水分变幅相对较小。播种期、五叶期及收获期土壤具有较高含水量,而开花期土壤含水量则较低。在两种轮作体系中,播种期春小麦和豌豆免耕秸秆覆盖处理0～50cm土层含水量分别较常规耕作增加28%、26%和11%、23%,降水生产效率较常规耕作提高了17.79%～26.81%。在春小麦豌豆轮作体系中免耕秸秆覆盖处理的作物产量(春小麦+豌豆)及水分利用效率分别为3420kghm2和8.11kg(hm2·mm),较常规耕作分别提高26.81%和25.39%。
Conservation tillage (conservationtillage) can reduce soil erosion and increase the yield of arable land, which is a kind of sustainable agricultural tillage with ecological protection significance. The results showed that the conservation tillage could significantly improve soil moisture storage and yield of 0-200 cm soil layer under the condition of conservation tillage in dry farmland of Dingxi from 2002 to 2004. The amount of water and water content, with the increase of precipitation, the ability of the soil to preserve precipitation increases. The effect of no-tillage straw mulching in the years with less precipitation is outstanding, while no-tillage mulch is more advantageous in the years of high precipitation. The soil moisture of topsoil changed drastically due to the influence of precipitation and other factors, and soil water amplitude below plowing layer was relatively small. Soil at seeding, five-leaf stage and harvest stage had higher water content, while soil water content at flowering stage was lower. In the two cropping systems, the water content of 0-50 cm soil layer of spring wheat and pea no-tillage straw mulching at seeding stage increased by 28%, 26% and 11% and 23% respectively compared with conventional tillage, and the precipitation productivity increased by 17.79 % ~ 26.81%. The yield of spring wheat + pea and water use efficiency of spring wheat and pea rotation were 3420 kghm2 and 8.11 kg (hm2 · mm), respectively, which were increased by 26.81% and 25.39% respectively compared with conventional tillage.