养分管理对油麦菜氮磷养分利用率及硝酸盐累积的影响

Effects of nutrient management on nutrient utilization of N,P and nitrate accumulation in lettuce

在云南滇池流域,采用田间小区试验的方法,研究了不同氮磷养分用量对油麦菜(Lactu-ca sativa var.ramosa)产量、硝酸盐含量及氮磷养分利用率的影响,以T1～T9分别表示9种处理方法.试验结果表明:①油麦菜产量以T3(N90P126K180)处理时相对较高,达到28 968.75 kg/ha;硝酸盐含量除T4(N180P126K180)、T5(N270P126K180)和T8(N180P189K180)外,其余处理污染等级均为四级;综合氮、磷养分利用率两项指标分析,T4(N180P126K180)与T9(N90P63K180)处理下油麦菜的养分利用率较高,分别为17.42%,2.10%与20.14%,2.05%.②同一钾肥施用量下,适量氮磷肥配施的处理,相应的油麦菜产量、硝酸盐含量及氮、磷养分利用率,在一定程度上优于偏施氮磷肥或过量施肥的处理.因此,控制氮磷肥施用量,合理优化氮磷配比,能提高养分利用率和蔬菜品质,是源头控制农业面源污染的重要途径.

By method of the field plot trial,the experiment was carried out in Dianchi Lake basin to study the influence of different nitrogen and phosphorus fertilizing on lettuce（Lactuca sativa var.ramosa） production,nitrate content and nutrient utilization of N,P.9 treatments were denoted by T1-T9,respectively.The results showed that： ① The lettuce production of T3（N90P126K180） was higher than other treatments,reaching 28 968.75 kg/ha;except for treatment of T4（N180P126K180）,T5（N270P126K180） and T8（N180P189K180）,the contamination levels of nitrate content of the others came out to be Lv.4;after comprehensive consideration on nutrient utilization of N,P,the nutrient utilization of Lettuce showed to be higher after treatments of T4（N180P126K180） and T9（N90P63K180） with 17.42%,2.10% and 20.14%,2.05% respectively.② Under the same amount of potash fertilizer and the treatment of appropriate nitrogen and phosphorus fertilizers match fertilizing,the corresponding lettuce production,nitrate content and N,P fertilizer nutrient utilization were superior to treatments of partial fertilization or high fertilization.Therefore,control of nitrogen and phosphorus fertilizing,reasonable optimization of ratios of nitrogen and phosphorus will improve the nutrient utilization and vegetables quality,which is of great importance for source controlling the agricultural non-point pollution.