Yu Kewei, Delaune Ronald D, Tao Rui, Beine Robert L
Dep, of Oceanography and Coastal Sciences, School of Coast and Environment, Louisiana State Univ., Baton Rouge, LA, USA.
J Environ Qual. 2008 Oct 23;37(6):2275-83. doi: 10.2134/jeq2008.0082. Print 2008 Nov-Dec.
A watershed analysis of nonpoint-source pollution associated with sugarcane (Saccharum officinarum L.) production was conducted. Runoff water samples following major rainfall events from two representative sugarcane fields (SC1 and SC2) were collected and analyzed. The impact of runoff on two receiving water bodies, St. James canal (SJC) and Bayou Chevreuil (BC) in a drainage basin (Baratarian Basin), was studied. Results show that runoff flow/rainfall ratios at the SC1 were significantly higher (P < 0.0001, n = 14) than at the SC2, probably mainly due to higher sand content and higher infiltration rate of surface soil at the SC2. In runoff water samples, total suspended solids (TSS) showed a significant correlation with the concentrations of N and P. Sugarcane runoff showed a direct impact on the SJC and BC locations where seasonal variations of pollutant concentrations in the waters followed the patterns of runoff loadings. Swamp forest runoff (SFR) location showed a buffering effect of forested wetlands on water quality with the lowest measured pollutant concentrations. The ratios in total N/total P and in inorganic N/organic N in runoff waters indicated that fertilization in spring greatly contributed to the temporal increase of N loadings, especially in forms of inorganic N. Isotope signature of (15)N-nitrate in the water samples verified that the nitrate was derived from fertilizers and was consumed during transportation. Both N and P concentrations in the receiving water bodies were above the eutrophic level. During the study period, herbicide concentrations in the receiving water bodies rarely exceeded the drinking water standards.
对与甘蔗（Saccharum officinarum L.）生产相关的非点源污染进行了流域分析。收集并分析了来自两个代表性甘蔗田（SC1和SC2）在主要降雨事件后的径流水样。研究了径流对流域（巴拉塔里亚流域）内两个受纳水体圣詹姆斯运河（SJC）和谢夫勒尔河（BC）的影响。结果表明，SC1处的径流流量/降雨比显著高于SC2处（P < 0.0001，n = 14），这可能主要是由于SC2处的砂含量较高以及表层土壤的入渗率较高。在径流水样中，总悬浮固体（TSS）与氮和磷的浓度呈现显著相关性。甘蔗径流对SJC和BC位置有直接影响，水体中污染物浓度的季节性变化遵循径流负荷模式。沼泽森林径流（SFR）位置显示出森林湿地对水质的缓冲作用，测得的污染物浓度最低。径流水体中总氮/总磷以及无机氮/有机氮的比例表明，春季施肥极大地导致了氮负荷的季节性增加，尤其是无机氮形式。水样中（15）N - 硝酸盐的同位素特征证实硝酸盐来自肥料并在运输过程中被消耗。受纳水体中的氮和磷浓度均高于富营养化水平。在研究期间，受纳水体中的除草剂浓度很少超过饮用水标准。
