Study On The Effect Of Nitrogen Phosphorus And Potassium Fertilization Of Purple Leaf Lettuce

Lettuce is rich in vitamins, minerals, protein, amino acids, sugars and other organic substances, is a widely cultivated and edible leaf vegetables in South China. With the improvement of people's living standard, purple leaf lettuce increasingly favored by consumer But in order to One-sided pursuit pursue production and economic income, the unreasonable phenomenon of excessive fertilization and fertilizer ratio is very serious. On the one hand, it increases the production cost and reduces the production efficiency, on the other hand, it's easy to cause physiological barriers to reduce product quality. This test use purple leaf lettuce as experimental materials, field plot experiment of nitrogen, phosphorus and potassium fertilizer use the "3414" method. Study the influence of'N P K'on purple lettuce growth, nutrient quality and nitrate content, anthocyanin content, aims to provide theoretical basis for the production of "high yield, high quality, high efficiency and safety" The main results are as follows:1. the application amount of nitrogen, phosphorus and potassium can effectively promote the purple leaf lettuce growth development, purple leaf lettuce strains with high nitrogen rate, stem diameter and amount of potassium showed significant positive correlation, nitrogen, the fresh weight of single plant was significantly improved by the reasonable application of N, P and K in N₂K₂P₂ treatment. Excessive application of nitrogen, phosphorus and potassium is not conducive to the growth of lettuce leaf and dry matter accumulation.2. Reasonable fertilization has significant effect on the yield of purple leaf lettuce, in this experiment, the treatment and no fertilization treatment yield increase between 19.03-49.49%, which handled 6 of the largest increase, Production efficiency is 489.67 yuan per mu, treatment 12 had the highest yield of 4.15. The equation for the function of N, P, K as the factor and the yield as the function was established, Y=1401.4478+22.821N +11.7315P+70.3111K-1.1762N²-8.4057P²-2.8066K²+4.248NP-0.52108NK+30.814718PK, the yield of lettuce were influenced by K>N>P, Through calculation of the equation under this experimental condition the most high yield rate of nitrogen, phosphorus and potassium respectively 17.27kg/667m²,5.63kg/667m²,and 11.73kg/667m², The optimal yield of fertilization was 17.35kg/667m²,4.96kg/667m²,3.60kg/667m².3. Different fertilization treatment on leaf yield and quality of lettuce have different effects and rational application of fertilizer can significantly improve the nutritional quality of purple leaf lettuce, the dosage is too low or too high are on the quality of the generated negative effect. Effect of Fertilization on the amino acid content of stem and size respectively is K>P>N, P>K>N.; Fertilization on purple leaf lettuce leaf and stem sugar influence size respectively is P>N>K, K>P>N; Effect of Fertilization on purple leaf lettuce leaves and stems of vitamin C size respectively is P>N>K, K>P>N.4. Nitrogen content and nitrate accumulation is proportional to the relationship, appropriately increase P and K fertilizer, can reduce nitrate accumulation, so as to improve the purple leaf lettuce health quality.5. A certain degree of rational fertilization could improve the purple leaf lettuce leaf anthocyanin content and the treatment of N₂P₁K₁ anthocyanin content was the highest for 41.28mg/100g. high nitrogen and high phosphorus conditions are not conducive to the synthesis of anthocyanins, potassium was positively correlated with leaf anthocyanin content.6. On the yield and quality of lettuce in purple multiple index comprehensive evaluation showed that comprehensive evaluation of the highest is N₂P₁K₂ followed by N₁P₂K₂ processing. N, P, K fertilization rates were 18.4kg/667m²,3kg/667m², 10.2kg/667m²,9.2kg/667m²,6kg/667m²,10.2kg/667m², and the lowest comprehensive evaluation was N₂P₂K₀ treatment, followed by N₀P₀K₀ treatment.