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对采用不同施肥和地表管理方式的梨园和菜地磷素的流失进行监测,研究了崇明东滩旱作农田土壤磷素的流失负荷、流失途径及其变化规律和影响因素,并分析了不同施肥和地表管理方式对农田土壤磷素流失的影响。结果表明,旱作农田土壤磷素径流流失、渗漏流失和泥沙流失浓度均超过水体富营养化总磷浓度临界值;土壤磷素流失以泥沙流失为主,泥沙总磷流失负荷占总磷流失总负荷的70.7%～82.2%;磷素流失主要发生在6、8和10月,这3个月总磷流失负荷占全年总磷流失总负荷的71.6%～73.0%。对磷素流失影响因素的相关分析表明,旱作农田土壤磷素流失与降雨量、降雨侵蚀力、径流量、径流水中总磷浓度等因素相关显著。与常规对照方式相比较,保持表土植被、覆盖地膜和精确滴灌,可减少旱作农田径流和泥沙产生量,降低总磷流失浓度,梨园和菜地总磷流失负荷消减率分别可达20.6%和12.6%。
The phosphorus loss in pear orchards and vegetable fields under different fertilization and surface management methods was monitored. The phosphorus loss, the way of loss and the influencing factors of soil phosphorus in the dry farmland of Chongming East Beach were studied, and the effects of different fertilization And the effect of surface management on phosphorus loss from farmland soil. The results showed that the runoff, leakage and sediment concentration of phosphorus in the dry farmland all exceeded the critical value of the total eutrophic phosphorus concentration in the dry farmland; the loss of phosphorus in the soil was mainly the sediment loss, the total phosphorus loss in the sediment accounted for The total phosphorus loss was 70.7% ~ 82.2% of the total phosphorus loss. Phosphorus loss occurred mainly in June, August and October. The total phosphorus loss in the three months accounted for 71.6% -73.0% of the total phosphorus loss in the whole year. The correlation analysis of the influencing factors of phosphorus loss showed that the phosphorus loss in dryland farmland was significantly correlated with rainfall, rainfall erosivity, runoff and total phosphorus concentration in runoff water. Compared with the conventional control, maintaining topsoil vegetation, covering plastic film and precise drip irrigation can reduce runoff and sediment production in dry farmland and reduce the total phosphorus loss concentration, and the reduction rate of total phosphorus loss load in pear orchard and vegetable field can reach 20.6% And 12.6%.