Long-term effect of integrated fertilization on maize yield and soil fertility in a calcaric fluvisol

In an 8-year study, the influence of integrated fertilization (combination of organic and inorganic fertilizers) on maize (Zea maysL.) yield and nutrition, with respect to nitrogen, phosphorus and potassium, at the different growth stages, was investigated in Quzhou County of the North China Plain. Three treatments were chosen for this study: inorganic fertilizers without organic fertilizers (IF), inorganic fertilizers plus low organic fertilizers (LOF) and inorganic fertilizers plus high organic fertilizers (HOF). The results showed that integrated fertilization significantly improved maize grain yield; the magnitude of increase in maize grain yield with HOF and LOF was 1.52 and 0.74 t ha(-1), respectively, over the IF (9.20 t ha(-1)). The total plant biomass and uptake of nitrogen, phosphorus and potassium in maize plants across growing stages were significantly improved with integrated fertilization. The integrated supply of nutrients was also beneficial in improving soil organic carbon, total nitrogen, available phosphorus and exchangeable potassium over the years. The result suggests that nutrient management practices for maize cultivation in the North China Plain should preferably include the integrated use of organic and inorganic fertilizers (3.75 t ha(-1)organic fertilizers supplemented with 125 kg N ha(-1)) to increase soil fertility and maize yield.