摘要
本文对瑞典南部一个区食物和饲料循环中的植物营养流作了定量分析。在牲畜密度比瑞典平均值高30%的农业系统中,氮和磷盈余分别为100kgN/hm^2和9kg P/hm^2,农业中的营养元素盈余与牲畜密度有关。大部分氮盈余以硝态氮和氨态氮的方式排放,而磷盈余则积累于土壤中。该区食物消费产生的有机废物中的营养元素相当于22kg N/hm^2和4kg P/hm^2,相对于耕地的人口密度比瑞典的平均值高15%。来自食物消费的剩余产品经过当前处理系统,食物摄入中11%的磷和低于3%的氮要再循环返回到耕地中。
Flows of plant nutrients in the food and the fodder cycle were quantified in a district in southern Sweden. In the agricultural system with a livestock density 30% higher than the Swedish average, the N-surplus was 100 kg N ha-1 and P-surplus was 9 kg P ha-1. There is a relation between nutrient surpluses in agriculture and livestock density. A large part of the N-surplus is emitted as nitrate-N and ammonia-N while the P-surplus accumulates in the soil. The nutrients in the organic waste from the food consumption in the district corresponded to 22 kg N ha-' and 4 kg P ha-1, the population density related to arable land was 15% higher than the Swedish average. Due to the present system of treatment of the surplus products from food consumption, 11% of P and less than 3% of N in the food intake were recycled back to arable land.
