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干旱缺水是渭北旱塬粮食生产的主要矛盾。长期采用单一土壤耕作,造成土壤紧实,蓄水纳墒和提供营养的能力变弱,直接影响作物产量的提高。多年研究和生产实践证明,建立与不同作物轮作方式相配套的土壤轮耕模式,可以为作物生长发育创造良好的土壤环境条件,保持农田生态健康发展,促进作物增产增收。于2007年秋季开始,选择在渭北旱塬陕西省合阳县一年一熟旱作“冬小麦→春玉米”轮作田,以连年免耕(CN)、连年深松(CS)和连年翻耕(CP)为对照,并将免耕(N)、深松(S)和翻耕(P)3种土壤耕作技术集成6种土壤轮耕模式。通过连续5年定位试验,研究了6种不同轮耕模式(N/S、S/P、P/N、N/P/S、N/N/S和P/P/S)对土壤容重、土壤孔隙度,田间持水量、水分状况以及水分利用效率(WUE)和经济效益的影响,为渭北旱塬半湿润易旱区建立在一定肥力水平下与作物轮作体系相配套的土壤轮耕模式提供理论依据。结果表明:(1)在040cm土层,6种轮耕模式中以S/P(深松→翻耕→深松→翻耕→深松)土壤物理状况最佳,与对照组相比(CN、CS和CP),土壤容重降低1.2%9.2%,土壤孔隙度和田间持水量分别增加0.3%6.8%和5.5%14.2%;(2)2个休闲期,夏闲期末0200cm土层土壤贮水量和蓄水率,以N/S最高,S/P次之,N/P/S最差;冬闲期末,以S/P(102.7 mm和24.9%)最高,P/N(翻耕→免耕→翻耕→免耕→翻耕)(102.3mm和24.8%)次之,以N/P/S(93.2mm和22.2%)最差;整个休闲期土壤水分状况则以N/S和N/N/S较好;(3)从5年整体效应看,两种作物平均,以平衡施肥下的S/P轮耕模式水分利用效率和经济效益最高,较其他处理组合分别高4.6%41.9%和11.6%58.4%(P<0.05)。
Drought and water shortage are the main contradictions of grain production in Weibei dryland. Long-term use of a single soil cultivation, resulting in soil compaction, soil moisture storage and nutrient supply capacity is weak, a direct impact on crop yield. Years of research and production practice have proved that establishing a soil rotation pattern that matches the rotation of different crops can create good soil environmental conditions for crop growth and development, maintain the ecological health of the farmland, and increase the yield of crops. In the autumn of 2007, the crop rotation “Winter Wheat → Spring Corn” was performed in Heyang County of Shaanxi Province in Weibei Arid Highland for one year. After no-tillage (CN) and successive years of deep-loosening (CS) (CP) as control, and integrated six types of soil rotation patterns with no-till (N), subsoiling (S) and tillage (P) Through five years of continuous positioning experiments, the effects of six different rotation patterns (N / S, S / P, P / N, N / P / S, N / N / S and P / P / S) Soil porosity, field water holding capacity, water status and water use efficiency (WUE) and economic benefits, we established a soil rotation model that matched the crop rotation system under a certain fertility level in semi-humid and arid areas of Weibei Arid Plateau Provide a theoretical basis. The results showed that: (1) Soil physical condition was the best under 0-40 cm soil layer and 6 rotation patterns with S / P (subsoiling → tillage → subsoiling → tilling → subsoiling) , CS and CP). Soil bulk density decreased 1.2% 9.2%, soil porosity and field water capacity increased 0.3% 6.8% and 5.5% 14.2% respectively. (2) Two leisure periods, soil water storage capacity at the end of summer (P <0.05). The highest N / S, the second was S / P and the second was N / P / S. → tillage → no tillage → tillage) (102.3mm and 24.8%) followed by N / P / S (93.2mm and 22.2%) respectively. The soil water status during the whole leisure period was N / S and N / N / S is better; (3) According to the overall effect of five years, the average water use efficiency and economic benefit of S / P rotation pattern under the balanced fertilization are the highest and the latter are 4.6% and 41.9% And 11.6% 58.4% (P <0.05).