猪场废水灌溉对潮土磷素肥力的影响

Effects of Swine Wastewater Irrigation on Phosphorus Fertility in Fluvo-aquic Soil

在北方缺水地区利用猪场废水对冬小麦进行小区灌溉试验,分析不同水质及水量灌溉处理土壤剖面全磷和速效磷的时空分布特征。结果表明:不同水质灌溉处理土壤全磷和速效磷在土层中的分布特征相似,均随深度增加含量逐渐减少;厌氧水不同灌溉量处理土壤全磷和速效磷含量与灌水量呈正比关系;收获后,各处理土壤耕层(0-40cm)磷素累积量均有所增加,磷素活化系数明显增大,大部分在7%～9%之间,高量厌氧水灌溉处理达到10.4%。采用未经处理的猪场废水多次灌溉后,过量磷素向下层土壤淋溶现象明显;高量厌氧水灌溉土壤耕层累积大量速效磷,易随地表径流污染周围水体。这两种类型的猪场废水不适于作为磷源进行农田灌溉。

Plot irrigation experiments with swine wastewater for winter wheat were conducted in water-lacked land of north China. Different treatment strategies of swine wastewater and irrigation quota of anaerobic wastewater were tested for the influence on the contents and distribution of total phosphorus,available phosphorus in the soil profiles with a depth of 100 cm throughout the growth season. The results showed that,for all treatments,available P and total P in soil had similar horizontal distribution that decreased with the increase of depth. The content of available P and total P mainly varied in the topsoil with a depth to 40 cm under irrigation with different amount of anaerobic wastewater during the wheat growing season,and followed a sequence： high quota〉middle quota〉low quota. Irrigation treatments with different treatment strategies of wastewater and quantity all increased the contents of total P and available P in soil after harvest. There was an significantly increase of percentage of available P in total P from 7% to 9% in various treatments,while the soil irrigated with high amount of anaerobic effluent reached 10.4%. Treatment with raw swine wastewater irrigation had a significant accumulation both of available P and total P in 40-100 cm soil layer. The leaching phenomenon also observed in anaerobic effluent treatments related to the increase of the irrigation quota. It was demonstrated that direct utility of swine wastewater and excessive anaerobic wastewater for irrigation should be avoided.