“稻-稻-四季豆”种植制度周年养分调控优化策略研究

Study on the Optimal Annual Nutrient Regulation Strategy for“Rice-Rice-Green Bean”Rotation System

【目的】研究“稻-稻-四季豆”种植制度下不同周年养分调控策略对作物产量和土壤肥力的影响,为广东省“稻-稻-菜”种植制度的高效施肥提供技术支持和理论参考。【方法】在广东省江门市开展田间试验,设置3个处理:CK,常规施肥;LNP,早稻季氮、磷减施20%,冬种四季豆和晚稻季等量施肥;OLNP,冬种四季豆磷减施10%,早稻季减氮10%,晚稻季减磷10%。比较不同处理对作物养分含量、产量和土壤肥力的影响。【结果】LNP处理的周年产量和生物量最高,其次是CK,OLNP处理最低。LNP处理和OLNP处理的作物氮、磷、钾含量与CK没有显著差异。OLNP处理可降低冬种蔬菜季土壤有效磷含量,降幅达9.71%;LNP处理早稻季的土壤氮含量显著低于CK,降幅为16.76%。LNP处理显著提高早稻季土壤蔗糖酶活性,OLNP处理的早稻蔗糖酶活性也较CK提高,而3个处理间的土壤过氧化氢酶、脱氢酶、β-葡糖甘酶、脲酶和酸性磷酸酶活性没有显著差异。【结论】LNP处理周年减少氮、磷用量6.25%和5.62%,可有效降低土壤氮、磷含量,减少养分流失风险,且作物不减产,为“稻-稻-菜”种植制度下较优的周年养分调控策略。

【Objective】The study was conducted to explore the effects of different annual fertilization strategies on crop yields and soil fertility in“Rice-Rice-Green bean”cropping system,and provide technical support and theoretical references for efficient fertilization for the“Rice-Rice-Vegetable”cropping system in Guangdong Province.【Method】Field experiment was carried out in Jiangmen City from 2015 to 2017.Three treatments were discussed:CK,conventional fertilization;LNP,N and P reduction by 20%in early rice season,and equivalent NPK fertilizers in winter green bean season and late rice season;OLNP,10%P reduction in winter green bean season,10%N reduction in early rice season,and 10%P reduction in late rice season,respectively.And the crop nutrient content,yield and soil fertility among different treatments were compared.【Result】The annual yield and biomass under LNP treatment were the highest,followed by CK and OLNP treatment.No significant difference in N,P and K contents of early rice,late rice and winter green-bean between LNP and OLNP treatments were observed.Soil available phosphorus in winter vegetable season decreased significantly under OLNP treatment,with a decease of 9.71%.And the soil available nitrogen content in early rice season under LNP treatment was significantly lower than that of CK,with a decrease of 16.76%.In addition,the activity of soil invertase under LNP treatment was improved significantly.Compared with CK,the invertase activity of OLNP treatment in early rice was also improved.No significant difference in the activities of catalase,dehydrogenase,β-glucosidase,urease and acid phosphatase among CK,LNP and OLNP treatments were detected.【Result】The LNP could reduce the application of N and P by 6.25%and 5.62%per year,effectively reduce the soil available nitrogen and phosphorus,reduce the risk of nutrient loss,and did not have negative influence on the crop yields.Therefore,LNP could be a better fertilization strategy for“Rice-Rice-Green bean”cropping system.