我国每年来自猪养殖过程中的粪尿数量巨大,其中蕴含了大量的氮素养分.根据2004年猪养殖统计数据,在确定不同养殖方式下(农户散养、集约化养殖)各猪种(育肥猪、母猪、幼猪)氮排泄参数基础上,对1999年和2004年我国农户散养和集约化养殖下各猪种粪尿N产生量进行了计算分析和对比.结果表明:(1)2004年我国猪粪尿N产生量约为1 293.1×104 t,空间变异性较大,主要集中在四川、湖南、河南等省;单位耕地面积猪粪尿N承载量全国平均值约为99.4 kg·hm-2,大部分省(市)都超过了均值,湖南省最高,达327.5 kg·hm-2,虽然北京、天津、上海三市猪粪尿N产生总量不多,分别仅占全国总量的0.6%、0.6%、0.3%,但其单位耕地面积猪粪尿N承载量却较大,分列第3、8、10位;全国农户散养下猪粪尿N产生总量约为集约化养殖下产生总量的2倍,除北京、上海、天津等省(市)集约化养殖猪粪尿N产生量较农户散养下产生量大外,其他省(市)散养猪粪尿N产生量均较集约化养殖大,两者比例在(1~8):1之间.(2)1999-2004年间,我国猪粪尿N产生量年平均增长41.2×104 t,增加量主要集中在四川、湖南、河南、山东、河北5省;各省(市)单位耕地面积猪粪尿N承载量也有不同程度地增加,但上海市则以年平均约11%的幅度下降,这与其控制当地养殖数量政策有直接关系;从1999-2004年变化趋势看,来自集约化养殖过程的猪粪尿N产生量所占比重呈现逐年增大的趋势.
There is a large amount of N nutrient from pig production in China each year. According to the amount and N excretion for different varieties of pigs under the house-holding and intensive breeding, the amount of N excretion in manure of pigs under different types of breed- ing was calculated in 2004. At the same time, in order to illuminate the trend of change of pig N excretion, comparison was done between 1999 and 2004. The results showed: 1) Total pig N excretion was 1 293.1×10^4 t in 2004, most of which was from Sichuan, Hunan, Henan provinces; Average unit pig N excretion per hectare (arable land) in China was 99.4 kg, and most provinces were more than average. The amount of pig N excretion in Beijing, Tianjin and Shanghai were not large, only accounting for 0.6%, 0.6% and 0.3% of the total, but N excretion per hectare were large, in the place of 3rd, 8th and 10th respectively. In a countrywide, the amount of pig N excretion under household breeding was about twice of that under intensive breeding. Except for Beijing, Shanghai and Tianjin et al, the former was more than the latter in other provinces (cities), and the ratio was in the range of (1-8):1.2) During 1999--2004, averaged pig N excretion increased 41.2×10^4 t annually, most of which was from Sichuan, Hunan, Henan, Shandong and Hebei provinces; Unit pig N excretion per hectare rose in most provinces (cities). However, Shanghai decreased by 11% per year, due to the policy of controlling the number of animals; According to the change of pig N excretion during 1999--2004, the ratio of pig N excretion from intensive breeding tended to increase.