Department of Soil and Physical Sciences, Lincoln University, Ellesmere Junction Road/Springs Road, Lincoln, 7647, New Zealand.
Institute of Environmental Science and Research Ltd, 27 Creyke Rd, Christchurch, 8041, New Zealand.
Environ Sci Pollut Res Int. 2020 Apr;27(11):11830-11841. doi: 10.1007/s11356-020-07759-8. Epub 2020 Jan 23.
Compared to discharge into waterways, land application of treated municipal effluent (TME) can reduce the need for both inorganic fertilizers and irrigation. However, TME irrigation may result in the accumulation of phosphorus (P) or trace elements in soil, and increased salinity and sodicity, which could damage soil structure and reduce infiltration. TME irrigation can also result in groundwater contamination through nitrate leaching or surface water contamination through runoff. This study aimed to evaluate the effects of increasing TME irrigation rates on quantity and quality of leachate and pasture growth in a lysimeter experiment using a Fluvial Recent soil and a Fragic Pallic soil. Pasture growth in the lysimeters was up to 2.5-fold higher in the TME treatments compared to the non-irrigated treatments. There were no signs of toxicity or accumulation of B, Al, Cd, Cu, Fe, Mn, As, and Zn. TME significantly increased the concentration of P and Na in the pasture. Nitrogen leaching from the lysimeters was negligible (< 1 kg/ha equiv.) in all treatments, but mineral N accumulated in the soil profile of the highest application rate (1672 mm/yr). Although more P was added than removed in pasture, the rate of accumulation indicated that over a 50-year period, P will still be within the current New Zealand thresholds for grazed pastures. Sodium accumulated in the soil columns in all the TME treatments. The rate of accumulation was not proportional to the TME application rate, indicating that Na was moving down through the soil profile and leaching. Results indicate a low to moderate risk of sodicity in soil or toxicity in plants caused by Na.
与排放到水道相比，经处理的城市污水（TME）的土地应用可以减少对无机肥料和灌溉的需求。然而，TME 灌溉可能导致磷（P）或微量元素在土壤中的积累，以及增加盐分和苏打度，这可能会破坏土壤结构并降低渗透性。TME 灌溉还可能通过硝酸盐淋溶导致地下水污染或通过径流导致地表水污染。本研究旨在评估增加 TME 灌溉率对 Fluvial Recent 土壤和 Fragic Pallic 土壤中淋出液数量和质量以及牧场生长的影响。与未灌溉处理相比，淋溶器中的牧场生长在 TME 处理中高达 2.5 倍。没有 B、Al、Cd、Cu、Fe、Mn、As 和 Zn 毒性或积累的迹象。TME 显著增加了牧场中 P 和 Na 的浓度。所有处理中，从淋溶器中淋出的氮都可以忽略不计（<1 kg/ha 当量），但在最高应用率（1672 mm/yr）的土壤剖面中积累了矿质氮。尽管牧场中添加的 P 多于去除的 P，但积累率表明，在 50 年内，P 仍将在新西兰当前放牧牧场的阈值范围内。所有 TME 处理中的土壤柱中都积累了 Na。积累率与 TME 应用率不成比例，表明 Na 正在向下通过土壤剖面并淋溶。结果表明，土壤中存在低到中度的钠碱化风险或 Na 对植物的毒性。
