Yield sustainability of paddy soil rice with long-term fertilization

【Objective】The objective of this study was to provide a basis for continuous production of rice by investigating the paddy soil productivity and yield sustainability with different fertilizer treatments.【Method】5long-term fertilization treatments,control(CK),chemical NK(NK),chemical NP(NP),chemical NPK(NPK),and manure plus chemical NPK(NPKM)in Jinxian,Jiangxi were selected.Effects of the long-term fertilization on yields of rice were analyzed and the sustainable yield index(SYI)was calculated.【Result】The yields of early-rice and late-rice of NK,NP,NPK and NPKM were improved significantly from 1981to 2005compared with CK.The yield of early-rice of NK treatment(70.8kg/(hm2·a))was extremely significantly lower than that of the CK,NP,NPK and NPKM treatments from 1981to 2005.The SYI values of early-rice were different from those of late-rice.The SYIs of both early-rice and late-rice under NPK and NPKM treatments were higher than those under other treatments.Late-rice under NPKM treatment had the highest SYI.SYI values were positively correlated with the yield of rice,but were nega-tively corrected with coefficient variation of rice.【Conclusion】Rational employ of chemical fertilizer and manure was an effective way to improve and sustain grain yields.