Rodvang S J, Mikalson D M, Ryan M C
Irrigation Branch, Alberta Agriculture, Food and Rural Development, Agriculture Center, 100, 5401 First Avenue South, Lethbridge, AB, T1J 4V6 Canada.
J Environ Qual. 2004 Mar-Apr;33(2):476-87. doi: 10.2134/jeq2004.4760.
Few studies have documented spatial and temporal variations in ground water quality in areas with high densities of animal farming operations (AFOs), or the long-term effects on surface-water quality. Changes in ground water quality were characterized in an irrigated area with a high density of AFOs in southern Alberta, Canada to evaluate the effect on ground water quality of manure application to fields. Fifty-five piezometers in the oxidized zone were sampled once or twice annually from 1995 to 2001, and temporal changes were analyzed using mixed model analysis. Average NO3- -N increased significantly from 12.5 to 17.4 mg L(-1) and average Cl- increased significantly from 19.4 to 34.4 mg L(-1) in piezometers installed in an unconfined sand aquifer at locations receiving fertilizer and manure. Compared with these manured locations, nitrate and chloride concentrations were significantly lower in shallow aquifer water in areas of pasture or native range, and concentrations did not change significantly with time. Nitrate and chloride concentrations in shallow ground water in fine-textured manured locations did not change significantly. Ground water below about 6 m in till and fine lacustrine sediments contains 18O signatures indicative of recharge under preirrigation or glacially influenced conditions, suggesting this ground water has a low vulnerability to agricultural contamination. Evaluations suggest that shallow ground water discharge will cause NO3- -N and Cl- in the Oldman River to increase by factors of at least 4.3 and 1.3, respectively, with more significant effects in smaller streams and under low-flow conditions.
很少有研究记录了动物养殖作业（AFOs）高密度地区地下水水质的时空变化，或对地表水水质的长期影响。在加拿大艾伯塔省南部一个AFOs高密度的灌溉区，对地下水水质变化进行了表征，以评估田间施用粪肥对地下水水质的影响。1995年至2001年期间，每年对氧化带中的55个测压管进行一次或两次采样，并使用混合模型分析来分析时间变化。在接受化肥和粪肥的无压砂质含水层中安装的测压管中，平均NO₃⁻-N从12.5毫克/升显著增加到17.4毫克/升，平均Cl⁻从19.4毫克/升显著增加到34.4毫克/升。与这些施用粪肥的地点相比，牧场或原生区域的浅层含水层水中硝酸盐和氯化物浓度显著较低，且浓度随时间没有显著变化。在质地细密且施用粪肥的地点，浅层地下水中的硝酸盐和氯化物浓度没有显著变化。在耕层和细粒湖相沉积物中约6米以下的地下水含有¹⁸O特征，表明是在灌溉前或受冰川影响的条件下补给的，这表明该地下水对农业污染的脆弱性较低。评估表明，浅层地下水排放将导致奥尔德曼河中NO₃⁻-N和Cl⁻分别至少增加4.3倍和1.3倍，在较小溪流和低流量条件下影响更为显著。
