Overuse of phosphorus (P) fertilizer and the resulting soil P accumulation in vegetable production increases the risk of P runoff and leaching. However, P transformations under continuous fertilization and their effects on environmental risk are unclear. The current study examined the effects of long-term P fertilizer application on P fractions in different soil layers, and assessed the correlations between P fractions and environmental risks in intensive vegetable production in a subtropical region. A total of 32 fields were studied, including 8 uncultivated fields and 24 fields continuously used for vegetable production for 1-3, 4-9, or 10-15 years. The results showed that excessive P fertilizer input caused soil P surpluses ranging from 204.6 to 252.4 kg ha^-1 yr^-1. Compared to uncultivated fields, vegetable fields contained higher levels of labile P, moderately labile P, sparingly labile P, and non-labile P. The combined percentage of labile P and moderately labile P increased from 55.2% in fields cultivated for 0-3 year to 65.5% in fields cultivated for 10-15 years. The concentrations of soil P fractions were higher at 0-20 cm soil depth than at 20-40 and 40-60 cm soil depth. Soil available P was positively correlated with all soil P fractions except diluted HCl-P_i or concentrated HCl-P_o. Long-term vegetable production increased CaCl₂-P downward movement, which was positively correlated with levels of labile and moderately labile P. The P index indicated a high risk of P losses from the vegetable fields. The P index was on average 3.27-fold higher in the vegetable fields than in uncultivated fields, and was significantly correlated with soil available P and organic and inorganic P fertilizer input. The environmental risk caused by P in vegetable production should be reduced by reducing P fertilizer input so as to maintain soil available P within an optimal range for vegetable production.

过量使用磷肥以及蔬菜生产中土壤磷的积累增加了磷径流和淋溶的风险。然而，在连续施肥下磷的转化及其对环境风险的影响尚不清楚。目前的研究调查了长期施用磷肥对不同土壤层中磷组分的影响，并评估了亚热带集约化蔬菜生产中磷组分与环境风险之间的相关性。共研究了32个田地，包括8个未耕地和24个连续用于1-3、4-9或10-15年的蔬菜生产的田地。结果表明，过量磷肥的施用导致土壤磷富集从204.6到252.4 kg ha ^-1 yr ^-1。与未耕地相比，蔬菜田中的不稳定磷，中等不稳定磷，少量不稳定磷和非不稳定磷含量更高。在0-3年耕作的土壤中，不稳定磷和中等不稳定磷的总百分比从55.2％增加在10-15年的耕地中达到65.5％。在土壤深度为0-20 cm时，土壤P分数的浓度高于土壤深度为20-40和40-60 cm时。除稀HCl-P _i或浓HCl- _Po外，土壤有效磷与所有土壤P组分呈正相关。长期蔬菜生产增加了CaCl ₂-P向下移动，与不稳定和中等不稳定的P水平呈正相关。P指数表明蔬菜田中磷流失的风险很高。蔬菜地的磷指数平均比未耕地高3.27倍，并且与土壤有效磷以及有机和无机磷肥料的投入显着相关。应通过减少磷肥的施用量来减少蔬菜生产中磷引起的环境风险，以将土壤有效磷保持在蔬菜生产的最佳范围内。