Effects of phosphorus fertilizer reduction on high-phosphorus clayey facility vegetable soils(高磷黏性设施菜地土壤磷肥减施效应研究)

To examine the integrated impacts of phosphorus (P) fertilizer reduction in a high-P facility vegetable system, a field experiment with five consecutive harvests of Chinese cabbage (Brassica rapa var. chinensis) was conducted on a typical high-P clayey vegetable soil (total P＞2 g/kg) in Hangzhou City of Zhejiang Province. The experiment included five treatments: conventional P application (P1) and P reduction by 25% (P2), 50% (P3), 75% (P4), and 100% (P5). The effects of P fertilizer reduction on Chinese cabbage growth, soil enhancement, and P activation were systematically evaluated. The results were as follows. 1) Compared with the P1 treatment, the P fertilizer reduction treatments did not inhibit the agronomic traits or the uptake of nitrogen and potassium in Chinese cabbage; instead, they overall promoted plant growth and increased yield by 23.54%-43.31%. The 75% P fertilizer reduction treatment (P4) showed the most pronounced yield-increasing effect, demonstrating a synergistic “P reduction with benefits” effect. 2) P fertilizer reduction improved soil physicochemical properties to some extent: the soil pH value increased by 0.04-0.11 units, and organic matter increased by 2.56%-8.26%; under the 25%-75% P reduction treatments (P2-P4), both the soil available P content and the P activation coefficient were higher than those under the P1 treatment. 3) P fertilizer reduction altered the profile of soil phosphatase activities, characterized by suppressing alkaline phosphatase activity and increasing neutral and acid phosphatase activities. In conclusion, a 75% P fertilizer reduction in high-P clayey facility vegetable soils can maintain a high yield of Chinese cabbage while effectively improving soil physicochemical and biological properties, thereby achieving both economic benefits and environmental sustainability.(在浙江省杭州市典型高磷黏性菜地（全磷＞2 g/kg）开展连续5茬青菜试验，系统探究磷肥减施对作物-土壤系统的综合效应。试验设常规施磷（P1）及减磷25%（P2）、50%（P3）、75%（P4）、100%（P5）5个处理，系统分析磷肥减施对青菜生长、土壤改良及磷素活化的协同效应。结果表明：1）与P1处理相比，减磷处理不仅未抑制青菜农艺性状及氮、钾养分吸收，反而整体上促进了植株生长，并提高产量23.54%～43.31%，其中减磷75%（P4）处理的增产效应最为显著，表现出“减磷增效”效应。2）磷肥减施在一定程度上改善了土壤理化性质。与P1处理相比，土壤pH值提高0.04～0.11个单位，有机质含量增加2.56%～8.26%；在减磷25%～75%（P2～P4）处理下，土壤有效磷含量与磷活化系数均高于P1处理。3）减磷处理改变了土壤磷酸酶活性格局，表现为碱性磷酸酶活性受到抑制，而中性和酸性磷酸酶活性增强。综上所述，在本研究的高磷黏性设施菜地中，实施75%的磷肥减量可在维持青菜高产的同时，有效改善土壤理化性质与生物性状，兼具经济效益与环境可持续性。)