Amin M G Mostofa, Pedersen Christina Østerballe, Forslund Anita, Veith Tamie L, Laegdsmand Mette
Department of Agroecology, Faculty of Science and Technology, Aarhus University, Blichers Alle 20, DK-8830, Tjele, Denmark; Department of Irrigation and Water Management, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh.
Danish Technological Institute, Kongsvang Allé 29, DK-8000, Aarhus C, Denmark.
J Environ Manage. 2016 Dec 15;184(Pt 2):289-296. doi: 10.1016/j.jenvman.2016.10.002. Epub 2016 Oct 8.
Animal manure application to agricultural land provides beneficial organic matter and nutrients but can spread harmful contaminants to the environment. Contamination of fresh produce, surface water and shallow groundwater with the manure-borne pollutants can be a critical concern. Leaching and persistence of nitrogen, microorganisms (bacteriophage, E. coli, and Enterococcus) and a group of steroid hormone (estrogens) were investigated after injection of swine slurry into either intact (structured) or disturbed (homogeneous repacked) soil. The slurry was injected into hexaplicate soil columns at a rate of 50 t ha and followed with four irrigation events: 3.5-h period at 10 mm h after 1, 2, 3, and 4 weeks. The disturbed columns delayed the leaching of a conservative tracer and microorganisms in the first irrigation event compared to the intact columns due to the effect of disturbed macropore flow paths. The slurry constituents that ended up in or near the macropore flow paths of the intact soil were presumably washed out relatively quickly in the first event. For the last three events the intact soil leached fewer microorganisms than the disturbed soil due to the bypassing effect of water through the macropore flow path in the intact soil. Estrogen leached from the intact soil in the first event only, but for the disturbed soil it was detected in the leachates of last two events also. Leaching from the later events was attributed to higher colloid transport from the disturbed soils. In contrast, NO-N leaching from the intact soil was higher for all events except the first event, probably due to a lower nitrification rate in the disturbed soil. A week after the last irrigation event, the redistribution of all slurry constituents except NO-N in most of the sections of the soil column was higher for the disturbed soil. Total recovery of E. coli was significantly higher from the disturbed soil and total leaching of mineral nitrogen was significantly lower from the disturbed soil. Results demonstrate how manure-borne constituents injected into undisturbed soil columns respond more as expected in the field, in terms of leaching and persistence, than do the same constituents injected into typically constructed columns of disturbed soil.
向农田施用动物粪便可提供有益的有机物质和养分，但也可能将有害污染物传播到环境中。粪便携带的污染物对新鲜农产品、地表水和浅层地下水的污染可能是一个关键问题。在将猪粪注入完整（结构化）或扰动（均匀重新装填）土壤后，对氮、微生物（噬菌体、大肠杆菌和肠球菌）以及一组类固醇激素（雌激素）的淋溶和持久性进行了研究。将猪粪以50 t/ha的速率注入六个重复的土壤柱中，随后进行四次灌溉：在第1、2、3和4周后，以10 mm/h的速率进行3.5小时的灌溉。与完整土壤柱相比，扰动土壤柱在第一次灌溉事件中延迟了保守示踪剂和微生物的淋溶，这是由于扰动的大孔隙流路的影响。完整土壤大孔隙流路中或附近的猪粪成分可能在第一次事件中相对较快地被冲走。在最后三次事件中，由于水通过完整土壤中大孔隙流路的旁路效应，完整土壤淋溶出的微生物比扰动土壤少。雌激素仅在第一次事件中从完整土壤中淋溶出来，但对于扰动土壤，在最后两次事件的渗滤液中也检测到了雌激素。后期事件的淋溶归因于扰动土壤中更高的胶体迁移。相比之下，除第一次事件外，完整土壤中NO-N的淋溶在所有事件中都更高，这可能是由于扰动土壤中的硝化速率较低。在最后一次灌溉事件一周后，扰动土壤中土壤柱大部分区域中除NO-N外的所有猪粪成分的重新分布更高。扰动土壤中大肠杆菌的总回收率显著更高，而扰动土壤中矿质氮的总淋溶量显著更低。结果表明，与注入典型构造的扰动土壤柱中的相同成分相比，注入未扰动土壤柱中的粪便携带成分在淋溶和持久性方面在田间的响应更符合预期。
