【摘要】 【目的】通过研究不同耕作模式对土壤性状及产量的影响,为成都平原主导耕作模式的筛选和调控技术提供理论依据。【方法】采用长期定位试验的方法,通过5年对5个处理[CK:麦稻双旋(WRCT)、麦免+稻旋(WNRCT)、麦稻双免(WRNT)、麦稻垄作(WRRT)、麦免+稻旋+秋作(WNRCVNT)]的大田试验研究,系统分析耕作模式对土壤性状和作物产量的影响。【结果】不同耕作模式对土壤性状的影响各不相同:与对照相比,单免和双免耕处理降低了0-10cm土层的容重,增加了10-20cm土层的土壤容重;增加了土壤的小孔隙、小孔隙的比例及0-10cm土层的大孔隙,降低了10-20cm的大孔隙,使土壤孔径分布得到改善。耕作措施对土壤吸湿水和土壤比重影响差异不显著,免耕降低了土壤比重。双免使土壤的渗水速率增加,不利于水稻生长,但单免能促进水稻生长。与对照相比,单免和双免耕秸秆覆盖增加了土壤有机质,降低了0-10cm土层的碱性,但增加了10-20cm土层的碱性。双免耕定位5年,增加了小麦产量,但大幅降低了水稻的产量。与此相反,单免则有利于小麦和水稻共同增产。【结论】免耕形成了"上松下紧"的土壤结构,改变了土壤的通透性,尤其是在10-20cm,打破了传统耕作的犁底层。但免耕对土壤结构的改变对小麦和水稻的产量影响并不一致:长期双免耕能促进小麦增产,但对水稻生长和产量不利。更多还原

【Abstract】 Objective In order to provide a theoretical basis for the main tillage systems and control technology of Chengdu plain,the effects of different tillages on soil properties and yield were compared.Method Based on long-term experiments,5 years of field trials were carried and the tillages on crop yield and soil properties and their relationship were analysed.The five treatments were wheat and rice conventional tillage(WRCT);wheat no-tillage and rice conventional tillage(WNRCT);wheat and rice no-tillage(WRNT);wheat and rice ridge tillage(WRRT);wheat no-tillage and rice conventional tillage and autumn vegetable no-tillage(WNRCVNT).Result The effects of different tillage systems on soil properties were different:Compared with the control,single and double no-tillage all reduced soil bulk density of the 0-10 cm layer,increased that of the 10-20 cm layer;which increased the small soil porosity,and increased the big soil porosity of the 0-10 cm layer,while increased the proportion of small pores,decreased the big soil porosity of the 10-20 cm layer,which improved the soil pore size distribution.It was not significantly different in soil specific gravity and soil hygroscopic water between tillage treatments.No-tillage decreased the soil specific gravity.The seepage rate of soil was increased too,which was not good for rice growth.No-tillage increased the soil organic.No-tillage straw mulching reduced alkalescence of the 0-10 cm soil layer,but increased alkalescence of the 10-20 cm soil layer.The average yield of five years showed that no-tillage increased wheat production,but significantly reduced rice production.Conclusion No-tillage resulted in the formation of "loose above and compact below" soil structure,which changed the soil permeability.Especially in the 10-20 cm,it broke the traditional plowpan.But no-tillage changed the soil structure which the effects on wheat and rice yield is not consistent.Under the same conditions,no-tillage is beneficial to increase wheat yield,but it is negative to rice growth and yield.The reason mainly due to no-tillage increased the rates of soil water seepage,and it caused leakage of water and nutrients seriously.更多还原