不同耕作措施对土壤质构和玉米产量的影响

通过4年定位试验，研究不同耕作措施对黑钙土区耕地土壤结构和质量以及玉米产量的影响。结果表明，播种前，和常规旋耕(CK)相比，深松旋耕(DP)、秸秆覆盖还田+深松(DSM)和秸秆深翻还田(PS)使土壤容重降低5.22%～11.19%，孔隙度增加5.09%～11.45%；DP、DSM处理土壤含水率分别提高14.99%和18.58%；DSM处理下>5 mm的团粒量与CK差异不显著，DP和PS处理使>5 mm的团粒比例降低，2～1 mm、1～0.5 mm和0.5～0.25 mm团粒比例升高。收获期，DSM、PS和DP处理的有机质含量较CK分别增加3.92、3.03和2.47 g/kg，DSM、PS和DP处理均能提高各时期土壤全量和速效养分含量，最终使玉米增产3.2%、6.8%和1.3%。从综合效应来看，秸秆覆盖还田+深松是黑钙土区更为适宜的耕作措施。

Effects of Different Tillage Measures on Soil Texture and Maize Yield

A 4- year field experiment was conducted to study the effects of different tillage measures on soil structure and quality and maize yield in chernozem region. The results showed that compared with conventional rotary tillage(CK) in the pre sowing stage, deep loosening, and rotary tillage(DP), straw mulching returning with subsoiling(DSM) and straw deep ploughing returning(PS) reduced soil bulk density by 5.22% to 11.19%, increased porosity by 5.09% to 11.45%, and increased soil moisture content by 14.99% and 18.58%, respectively. The amount of aggregate >5mm was no significant difference between DSM and CK, which was decreased under DP and PS measure but increased the proportion of 2-1 mm, 1-0.5 mm and 0.5-0.25 mm aggregates. Compared with CK, the organic matter content of DSM, PS and DP increased by 3.92 g/kg, 3.03 g/kg and 2.47 g/kg respectively in the harvest period. At the same time, DSM, PS and DP could increase soil total and available nutrient content in different periods, and increase maize yield by 3.2%, 6.8% and 1.3% respectively. From the comprehensive effect point of view, straw mulching returning with subsoiling is considered to be a more suitable tillage measure in chernozem area.