抚仙湖梁王河流域农业耕作与流域水质响应关系研究

以抚仙湖北岸梁王河流域为研究对象,选取流域中2种典型耕作方式水稻-小麦（R-W）轮作和烤烟-豌豆（T-P）轮作的农田.通过对农田地下水和梁王河水的同步观测及农田耕作情况的调查,发现移栽、施底肥、追肥及排水等耕作措施使地下水中TP、PO^3-₄-P、TN、NO^-₃-N和NH⁺₄-N含量在短时间尺度内有明显升高.农田作物在不同生育期对养分的吸收规律与地下水中的TP、PO^3-₄-P、TN、NO^-₃-N和NH⁺₄-N含量在长时间尺度上响应关系明显,作物处于对相应养分吸收高峰期时地下水中该养分含量就会明显降低,反之则会升高.梁王河水TP和PO^3-₄-P的含量在流域农田全处于耕作期时要比流域部分农田处于休闲期分别低5.8%和21.7%,而TN、NH⁺₄-N及NO^-₃-N含量在流域农田全处于耕作期要比流域部分农田处于休闲期分别高11.5%、242.6%和9.55%.

Response of Water Quality to Agricultural Cultivation in Liangwanghe River Catchment of Fuxianhu Lake Region

Response of water quality to agricultural cultivation was investigated for the Liangwanghe River catchment of Fuxianhu Lake region in Yunnan Province of China. Two typical tillage lands-the rice-wheat rotation (R-W) and the tobacco-pea (T-P) rotation were selected and monitored. Groundwater quality and water quality of Liangwanghe River were monitored simultaneously, as well as the farmland cultivation situation at that time. It was found that cultivation activities, such as transplanting, base fertilizer applying, top dressing, draining would cause apparent elevation of concentrations of TP, PO^3-₄-P, TN, NO^-₃-N and NH⁺₄-N of groundwater in a short time period. Nutrients adsorption by crops during different bearing periods has an obvious relationship to the change of contents of TP, PO^3-₄-P, TN, NO^-₃-N, and NH⁺₄-N in groundwater in a long time scale. When the crops are in a peak demand for nutrients, contents of nutrients in groundwater were found to reduce obviously, and contents of nutrients may rise for other crop conditions. Contents of TP and PO^3-₄-P of Liangwanghe River for full cultivation periods were found to be 5.8% and 21.7% lower than those for partial cultivation periods, while contents of TN, NH⁺₄-N and NO^-₃-N for full cultivation periods were found to be 11.5%, 242.6% and 9.55% higher than those for partial cultivation periods.