中文摘要：

【目的】陕西渭北旱塬属于暖温带半湿润易旱气候区，干旱对旱地农作物生产威胁严重，降水短缺及其季节分布不均制约着旱地冬小麦和春玉米生长发育，是导致作物产量低而不稳的主要因素。论文旨在探索渭北旱塬冬小麦—春玉米轮作区在不同轮耕措施下土壤蓄水保墒效果和作物增产增收效应。【方法】于2007—2013年在陕西合阳实施了免耕/深松、深松/翻耕、翻耕/免耕、连续翻耕等不同耕作处理田间定位试验，测定休闲期和作物生育期土壤水分及作物收获期土壤理化性状，分析各耕作处理作物产量和水分利用效率的变化规律。【结果】（1）3种耕作处理均能降低土壤容重，提高土壤孔隙度，增加田间持水量和土壤有机质，且以免耕/深松轮耕处理效果最佳，与连续翻耕相比，免耕/深松轮耕处理平均土壤容重较连续翻耕处理降低3.6%，平均土壤孔隙度、田间持水量和土壤有机质含量较连续翻耕处理分别增加4.4%、11.6%和6.9%。（2）在6个试验年度的3个休闲期间，平均土壤蓄墒率：免耕/深松＞翻耕/免耕＞深松/翻耕＞连续翻耕，免耕/深松、深松/翻耕和翻耕/免耕处理平均土壤蓄墒率较连续翻耕处理分别增加22.4个百分点、4.4个百分点和4.9个百分点，增墒效果显著；免耕/深松、深松/翻耕和翻耕/免耕处理0—200 cm土层平均土壤蓄水量较连续翻耕处理分别高18.2、1.3和11.8 mm。（3）在冬小麦生长期，免耕/深松、深松/翻耕和翻耕/免耕处理0—200 cm土层平均土壤蓄水量较连续翻耕处理分别增加13.2、1.7和14.6 mm；在春玉米生长期，免耕/深松和深松/翻耕处理0—200 cm土层平均土壤蓄水量较连续翻耕处理分别增加17.8和15.1 mm，深松/翻耕处理低于连续翻耕处理5.0 mm。（4）在冬小麦生产年度，免耕/深松、深松/翻耕和翻耕/免耕处理平均产量较连续翻耕处理分

英文摘要：

【Objective】Weibei highland of Shaanxi province belongs to warm temperate and semi-humid drought climate zone, so drought is the biggest limiting factor for crop production on dryland. Shortage of precipitation and uneven distribution in seasons are the main factors to cause the low and unstable yields of winter wheat and spring maize grown on dryland. The aim of this experiment is to study the effects of different rotational tillage patterns on soil water conservation, yield and benefit increase in winter wheat-spring maize rotation region in Weibei highland.【Method】The experiment of NT/ST （no-tillage in first year, subsoiling in second year, again no-tillage followed by alternating the next year）, ST/CT （subsoiling in first year, conventional tillage in second year, again subsoiling followed by alternating the next year） and CT/NT （conventional tillage in first year, no-tillage in second year, again conventional tillage followed by alternating the next year） rotational tillage, and continuous conventional tillage （CT） were conducted during 2007-2013 in Heyang, Shaanxi, and soil moisture was observed in fallow and crop growing periods, physicochemical characteristics of soil were observed in harvesting time, as well as crop yield and water use efficiency were analyzed. 【Result】 Compared with CT, three rotational tillage patterns significantly decreased soil bulk density, enhanced soil total porosity, field water capacity and soil organic matter. In harvesting period, the average soil bulk density under NT/ST treatment was 3.6% lower than CT treatment and average soil total porosity, field water capacity and soil organic matter was 4.4%, 11.6% and 6.9% higher than CT treatment. In fallow period, the average water conservation rate under NT/ST, ST/CT and CT/NT treatments was 22.4%, 4.4% and 4.9% higher than CT treatment, respectively. The average soil water storage in 0-200 mm soil layer under NT/ST, ST/CT and CT/NT treatments was 18.2 mm,1.3 mm and 11.8 mm higher than CT treatment. In w