潮土设施油麦菜田灌施猪场肥液的适宜模式研究

为有效控制畜禽养殖污水面源污染,通过设施菜田灌施猪场肥液田间试验,研究猪场肥液与清水不同稀释比例(不稀释,1:1,1:2,1:3,1:5)灌施条件下对油麦菜产量及土壤养分淋失的影响。结果表明,两季油麦菜土壤养分淋失特征存在一致性,不稀释猪场厌氧肥液灌施下土壤不同形态的碳、氮、磷淋失总量最高,总碳、总氮、总磷淋失量分别为637.2、242.1、12.2 mg·区^-1和149.6、61.44、1.13 mg·区^-1,是正常施肥处理的1.01~3.54倍。硝态氮为土壤氮淋溶的主要形式,占总氮淋溶量的84%~91%;无机碳淋溶量占总碳淋溶量的85%~90%,适宜浓度的厌氧肥液(1:2)灌施可有效降低土壤碳的淋溶,对土壤碳的固定起到积极作用。猪场肥液与清水1:2稀释灌施能够提高油麦菜存活率,且产量比对照施肥处理增加17.67%和18%,总碳、总氮、总磷淋失量比对照降低49%~56%、5%~44%和20%~34%。从提高油麦菜产量、控制土壤养分淋溶角度综合考虑,猪场厌氧肥液对油麦菜适宜的灌施模式为:肥液与清水1:2稀释灌施。

Influence of Irrigation with Anaerobic Effluent from Swine Farms on Leafy Lettuce Growth and Soil Nutrients in Fluvo-aquic Soil

The pollution from wastewater of the livestock and poultry breeding farms has become a severe environmental issue. However, such wastewater may be applied to agricultural land due to its nitrogen, phosphorus and other nutrients. Here, an experiment was carried out to investigate the growth of leafy lettuce and the dynamic of soil nutrients in fluvo-aquic soil irrigated with anaerobic effluent from swine farms. The effluent was applied at various dilutions(no dilution, 1:1, 1:2, 1:3, 1:5). Results showed that irrigation with no dilution caused the greatest leaching amounts of soil carbon, nitrogen and phosphorus. They were respectively 637.2 mg, 242.1 mg, and 12.2 mg per plot for the first season, and 149.6 mg, 61.44 mg, and 1.13 mg per plot for the second season, which were 1.01~3.54 times those of chemical fertilizer(CK). The leached inorganic carbon was 85%~90% of the total leached carbon. The main form of leached nitrogen was nitrate, accounting for 84%~91% of total leached nitrogen. However, irrigation with diluted anaerobic effluent could effectively reduce soil carbon leaching, showing a positive effect on soil carbon fixation. Compared with the CK treatment, application of 1:2 diluted wastewater increased the survival rate and the yield of leafy lettuce by 17.67% and 18%, but reduced leaching amount of total carbon, total nitrogen and total phosphorus by 49%~56%, 5%~44% and 20%~34%, respectively. In considering leafy lettuce yield, soil nutrient leaching losses and the prevention and control of non-point source pollution, it is suggested that the optimal dilution ratio of anaerobic water would be 1:2 for leafy lettuce production.