设施菜地利用强度对土壤磷形态分布及其有效性的影响——以江苏省水耕人为土和潮湿雏形土为例

以江苏省水耕人为土和潮湿雏形土两种土壤类型为对象,研究了设施菜地利用强度对土壤磷形态分布及其有效性的影响.结果表明:随利用强度增加,两种土壤类型的各磷形态含量均有所增加,以水溶态磷和铝结合态磷(Al-P)增加最为显著(P<0.05).而水耕人为土闭蓄态磷(O-P)占总磷百分比和潮湿雏形土残渣态磷占总磷百分比随利用强度增...

Effects of Greenhouse Vegetable Cultivation on Soil P Fractionations and Its Bioavailability

Intensive agricultural practices in greenhouse vegetable production (GVP), which involve much more fertilization, a high multi-cropping index and high productivity, have caused a large accumulation of soil P affecting its fractions and bioavailability to plants. In order to understand the influence of management strategies of GVP on soil P fractions and its bioavailability, soil samples encompassing a wide range of P status were collected in two typical GVP bases in Jiangsu Province: one with paddy soil in Guli, Nanjing and one with fluvo-aquic soil in Xiahu, Xuzhou. It was shown that Fe-P, O-P and organic P predominated in paddy soil, while Ca-P contributed the most in fluvo-aquic soil. The concentrations of soil available P, soluble P, Al-P, Fe-P, organic P, residual P in paddy soil and available, soluble P, Al-P, O-P, Ca-P, organic P in fluvo-aquic soil were found in accordance with management intensity at P < 0.05. Furthermore, the percentages of W-P and Al-P to total P for both soil types elevated significantly with the increasing of management intensity (P < 0.05), while O-P in paddy soil and residual P in fluvo-aquic soil declined clearly (P < 0.05). Stepwise regression analyses revealed that, Fe-P and Al-P gave major contributions to P bioavailability in paddy soil, while W-P and Ca-P in fluvo-aquic soil. It was worth noting that intensive agricultural inputs in GVP might increase the risk of P loss, especially for fluvo-aquic soil. Therefore, appropriate management strategies, such as paddy-upland rotation and lower fertilizer rate, are necessary to improve the bioavailability of soil P and achieve a sustainable progress of GVP.