Abstract:

Abstract： Thirteen treatments (check not contained ) with different combined application levels of Nitrogen, Phosphorus, Potassium fertilizer were conducted for testing the absorptive effects of Lettuce ( Lettuce sativa L.) by the“3414”designment. The results showed that the plant needs to assimilate pure Nitrogen（N）1.21～2.26 Kg (average 1.88 Kg ), Phosphorus (P2O5 ) 0.57～0.81 Kg (avr. 0.64Kg), Potassium ( K2O )2.97～5.09Kg （avr. 3.92 Kg ）from soil to produce 1000 Kg biomass yield, and the application ratio of Nitrogen, Phosphorus, and Potassium fertilizer was 3:1:6. The relationship between fertilizer application and yield prediction was analyzed in the application with a sole nutritional fertilizer or two nutritional fertilizers. With the result, we referred to this principle: “controlling N and P, increasing K” in lettuce field production. It was of great importance to decrease agricultural pollution in the point to use fertilizer optimally and reduce its loss.