长期定位试验研究了黄土高原西部旱农区传统耕作措施和5种保护性耕作措施对豌豆-小麦(P→W)和小麦-豌豆(W→P)轮作序列的耕层土壤肥力质量的影响。结果表明, 与传统耕作(T)处理相比, 传统耕作秸秆还田(TS)和免耕秸秆覆盖(NTS)处理有机质含量分别提高11.61%~12.21%和12.13%~16.99%, 全氮提高7.29%~8.42%和11.58%~12.95%, 全磷提高10.35%~14.63%和13.79%~18.29%, 全钾提高7.32%~7.51%和8.78%~9.15%, 速效磷提高11.10%~12.41%和16.29%~20.99%, 速效钾提高25.11%~43.26%和31.62%~44.22%, pH降低0.11~0.17个单位和0.09~0.16个单位。进一步利用加乘法则和加权综合法两种模型评价不同耕作方式下的土壤肥力质量, 结果表明, 土壤肥力质量指数排序为NTS处理>TS处理>NTP处理>NT处理>T处理>TP处理(P→W轮作序列)和NTS处理>TS处理>NT处理>NTP处理>TP处理>T处理(W→P轮作序列)。在黄土高原雨养农作系统中, 实施免耕结合秸秆覆盖, 对促进和维持土壤养分平衡, 提高土壤肥力质量具有重要意义。
Based on long-term field experiments in Dingxi, west of the Loess Plateau, the effects of conventional tillage (T) and 5 conservation agricultural patterns [conventional tillage with stubble incorporation (TS), no-till and no-stubble retention (NT), no-till with stubble retention (NTS), conventional tillage with plastic mulching (TP) and no-till with plastic mulching (NTP)] on the quality of soil fertility were studied for the rotation systems of pea-wheat (P→W) and wheat-pea (W→P) under rain-fed farming. The results show that soil fertility is improved by the two stubble retention systems, TS and NTS. Soil organic matter, total N, P and K, and available P and K under TS and NTS are much higher than those under T with respective increasing ranges of 11.61%~12.21% and 12.13%~16.99%, 7.29%~8.42% and 11.58%~12.95%, 10.35%~14.63% and 13.79%~18.29%, 7.32%~7.51% and 8.78%~9.15%, 11.10%~12.41% and 16.29%~20.99%, and 25.11%~43.26% and 31.62%~44.22%. On the contrary, soil pH under TS and NTS are lower than that under T with respective decreasing ranges of 0.11~0.17 and 0.09~0.16. Using addition/multiplication and weighted integrated methods, quantitative assessments of the quality of soil fertility in different tillage systems was performed. The order of the quality of soil fertility index ranked from high to low is NTS, TS, NTP, NT, T and TP for P→W rotation; and is NTS, TS, NT, NTP, TP and T for W→P rotation. This indicates that no-till with stubble retention replenishes soil nutrient pool and improves the quality of soil fertility in rain-fed areas of the Loess Plateau.