在模拟精度验证基础上,应用WinEPIC模型长周期定量模拟研究了19802009年渭北旱塬连作麦田夏闲期深松、免耕和翻耕等保护性耕作对冬小麦产量和土壤水分的影响. 结果表明:在30年模拟研究期间,不同耕作方式下渭北旱塬冬小麦产量和年度耗水量呈波动性下降趋势,深松处理产量和水分利用效率最高,30年平均值分别为3.33 t·hm~(-2)和8.50 kg·hm~(-2)·mm~(-1),其次为翻耕,免耕效果最差;深松处理麦田年度耗水量稍高于免耕和翻耕,冬小麦田0~3 m 土层土壤有效含水量呈现强烈的季节性波动降低趋势,免耕处理蓄水保墒效果最好,0~3 m 土层土壤有效含水量平均为89.5 mm,深松次之,翻耕最差.麦田0~1 m 土层土壤湿度随季节降水呈波动性变化,1~3 m 土层土壤湿度较为稳定,不同耕作处理间差异不大.长期连作小麦田深松处理的产量和水分综合效应最好,为渭北旱塬麦田最适宜的保护性耕作模式.
英文摘要:
Based on the verified precision results by simulation,the WinEPIC (EPIC,environmental/policy integrated climate model) was employed to quantitatively simulate effects of three conservation tillage practices adopted during the period of summer fallow, i.e. sub-soiling, no-tillage and conventional tillage, on wheat yield and soil moisture in Weibei Highlands during 1980-2009. The results showed that during the study period,the yield and annual water consumption of winter wheat under the different tillage practices tended to decrease with fluctuation in the growing period. The yield and water use efficiency of winter wheat under sub-soiling were the highest, averaging 3.33 t·hm~ (-2) and 8.50 kg·hm~(-2)·mm~(-1) over the thirty years, respectively, and that of no tillage was the lowest. The annual water consumption of winter wheat was slightly higher under sub-soiling than under no tillage and conventional tillage. In 0-3 m soil layer, the available soil water content tended to decline in a strongly and seasonally fluctuating manner. No tillage performed best in soil moisture conservation, with the average available soil water content being 89.5 mm, and that of conventional tillage was the lowest. The soil water moisture fluctuated with the seasonal rainfalls in 0-1 m soil layer and kept stable in 1-3 m with no great difference among the tillage practices. Under long-term continuous cropping,sub-soiling showed the best effects on the yield of winter wheat and the most comprehensive effect on soil moisture,and was the best practice of conservation tillage for wheat lands on Weibei Highlands.