Van Horn H H, Wilkie A C, Powers W J, Nordstedt R A
Department of Dairy and Poultry Sciences, University of Florida, Gainesville 32611.
J Dairy Sci. 1994 Jul;77(7):2008-30. doi: 10.3168/jds.S0022-0302(94)77147-2.
Dairy manure management systems should account for the fate of excreted nutrients that may be of environmental concern. Currently, regulatory oversight is directed primarily at the assurance of water quality; N is the most monitored element. Land application of manure at acceptable fertilizer levels to crops produced on the farm by hauling or by pumping flushed manure effluent through irrigation systems is the basis of most systems. Nutrient losses to surface and groundwaters can be avoided, and significant economic value can be obtained from manure as fertilizer if adequate crop production is possible. Dairies with insufficient crop production potential need affordable systems to concentrate manure nutrients, thereby reducing hauling costs and possibly producing a salable product. Precipitation of additional nutrients from flushed manures with sedimented solids may be possible. Composting of separated manure solids offers a possible method to stabilize solids for distribution, but, most often, solids separated from dairy manures are fibrous and low in fertility. Manure solids combined with wastes from other sources may have potential if a marketable product can be produced or if sufficient subsidy is received for processing supplementary wastes. Solutions to odor problems are needed. Energy generated from manure organic matter, via anaerobic digestion, reduces atmospheric emissions of methane and odorous compounds. Use of constructed wetlands or harvesting of photosynthetic biomass from wastewater has the potential to improve water quality, making extensive recycling possible.
奶牛粪便管理系统应考虑到可能引起环境问题的排泄养分的去向。目前，监管主要针对水质保障；氮是监测最多的元素。通过拖运或将冲洗后的粪便废水通过灌溉系统泵送至农场种植的作物上，以可接受的肥料水平施用粪便，这是大多数系统的基础。如果能够实现充足的作物产量，就可以避免养分流失到地表水和地下水中，并且粪便作为肥料还能获得显著的经济价值。作物生产潜力不足的奶牛场需要经济实惠的系统来浓缩粪便养分，从而降低运输成本，并有可能生产出可销售的产品。有可能从冲洗后的粪便与沉淀固体中沉淀出额外的养分。对分离出的粪便固体进行堆肥处理，可为稳定固体以便于分发提供一种可行方法，但通常情况下，从奶牛粪便中分离出的固体纤维含量高且肥力低。如果能够生产出可销售的产品，或者在处理补充废物时获得足够补贴，那么将粪便固体与其他来源的废物相结合可能具有潜力。需要解决气味问题。通过厌氧消化从粪便有机物中产生的能源，可减少甲烷和有气味化合物的大气排放。利用人工湿地或从废水中收获光合生物质，有可能改善水质，从而实现广泛的循环利用。
