Studies on the Absorption and Utilization of Nutrients for Head Lettuce under Protectorate Condition

Through the experiment in different methods of fertilizer application, the relationship among head lettuce yield, nutrient absorption,change of soil nutrient contents, contents of nitrate and the fertilizer-N,P use efficiency was researched under protectorate condition for the reasonable method of fertilizer application and the improvement of fertilizer use efficiency. The results showed that rational application of N, P2O5 and K2O (N 240?kg/hm2, P2O5 120?kg/hm2, K2O 300?kg/hm2 in this experiment) could improve the nutrient absorption of head lettuce, improve fertilizer-N,P use efficiency, decrease nitrate concentration in head lettuce and nitrate residual in soil, therefore minimize leakage of nitrate-N and P which formed serious threats to environment pollution, and improve the quality of head lettuce.