Phosphorus Fertilization Modes Affect Crop Yield, Nutrient Uptake, and Soil Biological Properties in the Rice–Wheat Cropping System

Long‐term application of P fertilizer has resulted in P overabundance in farmland and environmental pollution in the middle and lower reaches of the Yangtze River in China. Field experiments were performed to investigate the effects of different P fertilizer application modes on crop yield, nutrient uptake, soil enzyme activity, number of microbes (bacteria, actinomycetes, and fungi), and diversity of microbes in rice ( Oryza sativa L.)–wheat ( Triticum aestivum L.) rotation system. The results showed that a 20% reduction of the traditional application amount of P fertilizer did not cause decreases in crop yield, amount of nutrient uptake, soil enzyme activity, or the number of soil microbes. In addition, both the 20% reduction in applied P and the mixed application of organic manure and chemical P fertilizer increased not only the activity of neutral phosphatase, sucrase, protease and urease, but also the number of soil microbes, as well as the Shannon's microbial diversity index (H), although they had no impact on crop yield and nutrient uptake. A 20% reduction of P fertilizer could be a possible agricultural measure for reducing farmland pollution, and the combined application of organic manure and chemical P fertilizer could be recommended for improving soil fertility in the study areas.