连续稻茬油菜免耕对土壤理化性状影响的研究

[目的]探讨稻茬油菜免耕栽培机理。[方法]对连续多年免耕土壤进行取样,分析稻田油菜免耕土壤的各项理化性状指标,分析其对土壤结构性状的影响。[结果]免耕模式可以明显改善土壤的物理性状,对表层土容重的改善和土壤微团聚体含量的增加有积极的作用,有利增加土壤含水量,土壤总孔隙度呈逐年下降趋势。免耕模式还能够增加土壤有机质含量,有利肥沃土壤及作物生长发育,还能减小pH值却不至于酸化土壤,但是对土壤速效养分的影响却不明显。免耕土壤的速效养分均逐年上升,虽增幅不大但仍大于对照。表土层速效氮平均每年增加2.5 mg/kg,速效磷每年增幅为2.0 mg/kg,速效钾为1.25 mg/kg。[结论]该研究为大面积稻茬油菜免耕技术支撑提供理论依据。

Study on Effect of No-tillage Soil with Continued Planting Pattern of Rice-rape on Physical-chemical Character of Soil

[Objective] The study aimed to discuss the cultivation mechanism of rice stubble rape.[Method] The soils with continued no-tillage for many years were sampled to analyze their physical-chemical characters and their effects on soil structure characters.[Result] The no-tillage mode could obviously improve the physical characters of soil and density of surface layer soil,and enhanced the microaggregate content of soil,which was favorable to increase the water content in soil and made the total porosity of soil to decrease every year.The no-tillage mode could also increase the organic matter content of soil,which was favorable to the soil enrichment and the growth and development of crops.It still could reduce pH to the degree that the soil couldn't be in acidification,but its effect on the available nutrient content in soil wasn't obvious.The available nutrients in no-tillage soil were all increased year by year,though their increasing amplitude was little,they were greater than CK.The average available N in surface soil was increased by 2.5 mg/kg,available P increased by 2.0 mg/kg and available K by 1.25 mg/kg every year.[Conclusion] This study provides the theoretical basis for the no-tillage technique support of rice stubble rape planting in large area.