Harper Lowry A, Weaver Kim H, Dotson Richard A
Southern Piedmont Conservation Research Unit--JPCSNRCC, USDA-ARS, 1420 Experiment Station Road, Watkinsville, GA 30677, USA.
J Environ Qual. 2006 Jan 5;35(1):224-30. doi: 10.2134/jeq2004.0288. Print 2006 Jan-Feb.
In animal production systems (poultry, beef, and swine), current production, storage, and disposal techniques present a challenge to manage wastes to minimize the emissions of trace gases within relatively small geographical areas. Physical and chemical parameters were measured on primary and secondary lagoons on three different swine farming systems, three replicates each, in the Central Great Basin of the United States to determine ammonia (NH3) emissions. Nutrient concentrations, lagoon water temperature, and micrometeorological data from these measurements were used with a published process model to calculate emissions. Annual cycling of emissions was determined in relation to climatic factors and wind speed was found the predominating factor when the lagoon temperatures were above about 3 degrees C. Total NH3 emissions increased in the order of smallest to largest: nursery, sow, and finisher farms. However, emissions on an animal basis increased from nursery animals being lowest to sow animals being highest. When emissions were compared to the amount of nitrogen (N) fed to the animals, NH3 emissions from sows were lowest with emissions from finisher animals highest. Ammonia emissions were compared to similar farm production systems in the humid East of the United States and found to be similar for finisher animals but had much lower emissions than comparable humid East sow production. Published estimates of NH3 emissions from lagoons ranged from 36 to 70% of feed input (no error range) compared to our emissions determined from a process model of 9.8% with an estimated range of +/-4%.
在动物生产系统(家禽、牛肉和猪肉生产)中,当前的生产、储存和处理技术对在相对较小的地理区域内管理废物以尽量减少微量气体排放构成了挑战。在美国中部大盆地的三种不同养猪系统的一级和二级泻湖进行了物理和化学参数测量,每种系统有三个重复样本,以确定氨(NH₃)排放。这些测量得到的营养物浓度、泻湖水温和微气象数据与一个已发表的过程模型一起用于计算排放量。确定了排放的年度循环与气候因素的关系,发现当泻湖温度高于约3摄氏度时,风速是主要因素。总NH₃排放量从小到大依次为:保育场、母猪场和育肥猪场。然而,按动物个体计算的排放量从保育动物最低到母猪最高。当将排放量与喂给动物的氮(N)量进行比较时,母猪的NH₃排放量最低,育肥动物的排放量最高。将氨排放量与美国东部潮湿地区类似的农场生产系统进行比较,发现育肥动物的排放量相似,但比美国东部潮湿地区类似的母猪生产排放量低得多。已发表的泻湖NH₃排放量估计值占饲料输入量的36%至70%(无误差范围),而我们根据过程模型确定的排放量为9.8%,估计范围为±4%。