中文摘要：

耕作和秸秆还田是打破犁底层、改善黑土肥力的重要措施。本研究利用田间试验,分析了耕作和秸秆还田对秸秆腐殖化系数、总有机质含量（SOC）和玉米产量的影响。结果表明：深耕＋秸秆施入20-35 cm（ST＋S）能够打破犁底层,与浅耕（TT）、深耕（ST）和浅耕＋秸秆还田（TT＋S）相比,试验6年间容重平均降低了5.7%、3.3%和5.7%,其中ST和ST＋S试验第一年效果最好;试验6年后秸秆腐解率表现为0-20 cm土层（72.0%）〉20-35 cm土层（59.2%）;0-20和20-35 cm土层秸秆腐殖化系数在试验的第一年达到了最大值,分别为15.9%和12.7%;与初始土壤相比,TT、ST和ST＋S处理0-20 cm土层SOC和轻组有机碳（LFOC）呈下降趋势,而TT＋S处理分别增加了2.9%和12.4%,ST＋S处理20-35 cm土层分别增加了9.2%和9.9%;对玉米产量的影响表现为ST＋S〉TT＋S〉ST〉TT,耕作和秸秆还田的时间效应明显,其中ST处理玉米产量的影响可以持续3年,而ST＋S处理可以持续6年。因此,通过耕作的方式将秸秆施入20-35 cm土层是一种有效的、可持续改善黑土质量的农业措施。

英文摘要：

Tillage and straw incorporation are important agricultural practices that can break plough layer and improve black soil fertility. The effects of tillage and straw incorporation on straw humifi- cation coefficient, soil organic carbon （SOC） , and maize yield were investigated in a field experi- ment. Subsoil combined with straw incorporation in 20-35 cm soil layer （ST ＋ S ） could break plough layer and decrease the bulk density by 5.7%, 3.3% and 5.7% compared with traditional til- lage （ TT）, subsoil （ST） and traditional tillage combined with straw incorporation （TT＋S） in six experimental years, respectively, and the best effects were observed in ST and ST＋S treatments in the first expe-rimental year. The rate of straw decomposition was higher in 0-20 cm （72.0%） than in 20-35 cm （59.2%） , and the straw humification coefficient in 0-20 cm and 20-35 cm soil la- yers reached the peak in first experimental year with 15.9% and 12.7%, respectively. Compared with initial soil sample, SOC and light fraction organic carbon （LFOC） of TF, ST and ST＋S treatments in 0-20 cm soil layer was decreased in experimental years, but was increased by 2.9% and 12.4% within TY＋S, respectively. SOC and light fraction organic carbon （LFOC） of ST＋S in 20-35 cm soil layer was increased by 9.2% and 9.9%, respectively. The effect of field treatments on maize yield showed in a decreasing trend of ST＋S〉TT＋S〉ST〉TT, effects of tillage and straw incorporation on maize yield could continue 3 and 6 years, respectively, indicating that tillage and ration had time effect. Therefore, straw incorporated into 20-35 cm soil layer based an effective, sustainable agricultural practice of improving black soil quality.