Experiment on “2+X” Total Nitrogen Control in Field of Lettuce

The field fertilization experiment of "2+X" total nitrogen fertilizer control was carried out to further optimize the local fertilization techniques for lettuce. The results showed that the formula fertilization scheme per 667 m² of N 23 kg、P₂O₅ 11.44 kg and K₂O 20.70 kg for lettuce used in this experiment had an extremely significant effect in yield increase compared with the local customary fertilization. Under the conditions of this experiment, the yield of lettuce increased first and then decreased with the increase of nitrogen application rate. When the nitrogen application rate was 25.40 kg, the yield of lettuce was the highest, and the optimal economic fertilizer application rate was 25.03 kg.