持续六年施用不同磷肥对稻田土壤磷库的影响

Response of Soil Phosphorus Pool after 6 Years Application of Different Phosphorus Fertilizers in a Paddy Field

以草甸棕壤稻田为研究对象,采用磷素分级方法研究持续6年施用不同磷肥对稻田土壤磷库组成及磷有效性的影响,明确最有效培肥稻田土壤的磷肥品种。结果表明,持续6年施用不同磷肥土壤无机态磷占土壤磷库的65.64%~81.30%,有机态磷占土壤磷库的18.70%~34.36%;施用不同磷肥均可增加土壤无机磷含量,其中施用磷酸二铵、重钙、过磷酸钙等常规无机磷肥土壤有机磷含量显著增加。施用包膜或含有机酸磷肥的土壤有机磷含量显著低于施用常规无机磷肥土壤。施用包膜或含有机酸磷肥可显著提高磷有效性,施用包膜重钙效果最好。含有机酸磷肥尽管能活化磷素,但也会导致养分流失。施用包膜或含有机酸磷肥是提高土壤磷素库容的有效措施。

In order to identify the most effective phosphorus（P） fertilizer in rice soil developed from meadow brown soil, a 6-year paddy field experiment was conducted to clarify the change patterns of soil P pools and P availability under different P fertilizers application. The results showed that soil inorganic P accounted for 65.64%-81.30% of the soil P pool, and organic P accounted for 18.70%-34.36%. Soil inorganic P content was increased with all types of P fertilizers application and soil organic P was only increased significantly with the application of diammonium phosphate（DP）, triple superphosphate（TSP） and superphosphate（SP） compared with CK. Coated or organic acid added DP, TSP and SP increased soil organic P significantly compared with routine fertilizers. Soil P availability was increased significantly in the treatments with the application of coated or organic acid added P fertilizers and treatments with coated TSP exhibited the highest soil P availability. Organic acid added P fertilizers increased P availability while it could also induce P loss. The results showed that combined application of coated or organic acid added P fertilizers is the effective method to increase P storage capacity in meadow brown soil rice field.