Effects of subsoiling on soil moisture under No-tillage 2 years later

Китайский. 研究两年免耕后深松对土壤水分的影响，提高保护性耕作条件下对土壤水分的利用效率。土壤免耕第3年的基础上深松40 cm，2005～2006年连续两年通过田间试验观测深松对土壤水分的影响，分析深松保墒增产的机理。莜麦作物生育期0～100 cm土壤贮水量，深松显著高于对照。在0～100 cm的土层剖面上，50～100 cm土壤水分含量深松显著高于对照，干旱少雨时，土壤水分含量随土层深度增加而增加；降雨集中时，随土层深度增加而减少。与对照相比，深松减少了0～50 cm的作物耗水量,促进根系对50～100 cm土层土壤水分的消耗。土壤深松处理比对照两年平均增产18.29％，水分利用效率增加9.68％。保墒增产效果受降水量的影响，分布均匀的降雨有利于增产并提高水分利用效率。另一方面，深松降低了表层土层容重，增加接纳雨水的能力，增强作物对水分的利用效率。在免耕的基础上深松，是北方农牧交错带有效增加水分利用效率的保护性轮耕措施。

Английский. In order to improve the water use efficiency under conservation tillage, the effects of subsoiling on soil moisture under no-tillage 2 years later was studied. A field experiment of 40 cm subsoiling under no-tillage 2 years later was operated from 2005 to 2006. Based on the data of soil moisture and crop yield, the physical basis of subsoiling for water conservation and yield increasing was analyzed. Soil water storage under subsoiling from soil surface to top 100 cm was more than no-tillage in growth season. In 0-100cm soil depth, the soil moisture in 50-100 cm depth under subsoiling were higher compared with no-tillage, which increased when it was dry and scarce in rain and decreased when it was rainy with soil depth increasing. Compared with no-tillage, subsoiling reduced the water consumption of oats in the 0-50 cm depth and increased the water consumption in the 50-100 cm depth. Compared to no-tillage, subsoiling increased the yield by 18.29% and water use efficiency by 16.8% in two years average. The effects of subsoiling on water conservation and yield increase were affected by precipitation, well-proportioned rainfall was better to increase yield and water use efficiency. Meanwhile, subsoiling decreased bulk density, which increased the available precipitation. Subsoiling under no-tillage is an effective rotation tillage to content of more soil moisture and improvement of water use efficiency in ecotone of north China.