【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. |