沼液灌溉对紫色土菜地土壤特性的影响

三峡库区山地城镇重肥效的沼液灌溉,既需做到能够充分利用粪污资源,又要不破坏植物的生长与土壤环境。试验采用某大型奶牛养殖场粪污处理站不同阶段的废水进行灌溉,其中包括:沉砂池污水(grit chamber wastewater,GCW)、集水池污水(collection basin wastewater,CBW)、厌氧池沼液(anaerobic tank wastewater,ATW)、好氧池出水(aerobic effluent,AE),并以清水(clean water,CW)作为对照组,5组试验平行同步对紫色土试验样地进行灌溉。土壤剖面铵态氮含量在0～5cm土层ATW为最大860mg/kg,5～10cm土层5个试验组含量略有升高,10～20cm土层试验组GCW、CBW、ATW、AE呈下降趋势。硝态氮含量在0～5cm土层仍是ATW最大为23.95mg/kg。有效磷在0～5cm土层5组试验都低于100mg/kg,5～10cm土层试验组CBW和CW含量上升较大分别为10%和11%,5个试验组总体磷吸收能力都为弱。在沼灌土壤自身承载量的试验中,土壤承载铵态氮最大值为1355mg/kg,硝态氮24.65mg/kg,有效磷为163.66mg/kg,磷吸收系数在第5～9d高于500。通过前期不同阶段污水灌溉研究氮、磷积累吸附及土壤自身承载力的试验,确定沼液灌溉能提供较多有效氮、磷的优良可行性,并为进一步提出合理灌溉量和实际操作提供指导。

Characteristics of purple vegetable soil under biogas slurry irrigation

Biogas slurry irrigation at Mountain town in the reservoir area of Three Gorges was demanded not only by taking full advantage of dung resources, but also not destroying the growth of plants and soil environment. This research used the wastewater from a dairy farm in the southwest, including grit chamber wastewater (GCW), collection basin wastewater (CBW), anaerobic tank wastewater (ATW), aerobic effluent (AE) and clean water (CW) for parallel irrigation in the greenhouse. The experiments indicated that ATW contained the maximum ammonia nitrogen content of 860 mg / kg in 0-5 cm soil profile sample. In 0-5 cm soil profile samples, the content of nitrate nitrogen in ATW remained the highest with 23.95mg / kg. In 5-10 cm and 10-20 cm soil profile samples, the nitrate nitrogen content of the other four test groups increased and reached the final value of 23.67 mg/kg. In 0-5 cm from soil surface the phosphorus content of the five groups were less than 100 mg/kg. The phosphorus absorption coefficient of CW reached a peak value of 570 after half a month. And the maximum content of ammonium nitrogen, nitrate, and available phosphorus were 1355 mg/kg, 24.65 mg/kg, and 163.66 mg/kg respectively. The phosphorus absorption coefficient in the 5th to 9th day was more than 500. According to the research of different irrigation water quality contrasting, nitrogen and phosphorus accumulation and adsorption, soil bearing capacity test, the load of biogas slurry irrigation provides references to further the reasonable irrigation and the actual operation.