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

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.