Effects Of Long-Term Application Of Nitrogen Fertilizer On Calcium,Magnesium,Sulfur Content And Tomato Quality In Vegetable Field

Based on the study of 28-year long-term fertilization experiment,.the tomato variety "Golden Delicious No.8" was used as the test material.Six of them were selected:organic fertilizer combined with nitrogen fertilizer(AN1,AN2),no organic fertilizer(BN1,BN2),only the application of organic fertilizer(AN0)and non-fertilizers(BN0)were studied.The effect of nitrogen fertilizer on soil nutrient(calcium,magnesium and sulfur)was studied.The changes of calcium,magnesium and sulfur contents in the soil of the cultivated field were.discussed,and the scientific basis for improving the yield and quality of tomato was discussed.The results of the trial are as follows:1.The results showed that the relative chlorophyll content,plant height and stem diameter of tomato plant leaves were higher than that of non-nitrogen fertilizer.Under the condition of double application of double nitrogen fertilizer,the relative chlorophyll content and stem diameter increased,While the plant height began to decline.The relative chlorophyll content and stem diameter of organic manure combined with nitrogen fertilizer increased with the increase of nitrogen fertilizer,while the plant height decreased.2.It was found that organic manure combined with nitrogen fertilizer could significantly increase the contents of OM,AN,AP and AK in soil.PH decreased with the increase of nitrogen application rate.The conductivity and the content of available N increased with the increase of nitrogen application rate.3.The maximum content of calcium was 1314.21 mg/kg,the maximum magnesium content was 203.23 mg/kg,and the sulfur content was 0.67 mg/kg,with the maximum content of copper in the single organic fertilizer treatment.The content of calcium,magnesium and sulfur in soil increased with the increase of nitrogen.fertilizer,and the content of calcium,magnesium and sulfur in soil was significantly increased by organic fertilizer and nitrogen fertilizer.According to the correlation analysis,the contents of calcium,magnesium and sulfur in soil were positively correlated with organic matter,available phosphorus and available potassium,and the correlation coefficients were above 0.526.4.It is clear that organic manure combined with nitrogen fertilizer can significantly increase the content of magnesium and sulfur in tomato fruit,but it has little effect on calcium.In a certain range,the application of nitrogen fertilizer is beneficial to tomato fruit calcium,magnesium,sulfur content increased,but excessive nitrogen fertilizer lead to calcium,magnesium,sulfur content decreased.According to the correlation analysis,the contents of calcium,magnesium and sulfur in tomato fruit were positively correlated with OM and AK.There was a significant positive correlation between magnesim and OM,AP and AK,while calcium and AN were negatively correlated with AN.5.It is clear that organic manure can increase the content of vitamin C,reducing sugar,soluble sugar and organic acid.With the increase of nitrogen fertilizer,the content of organic acid and reducing sugar is also increased.Organic fertilizer combined with nitrogen fertilizer on tomato yield and fruit weight greater impact,nitrogen fertilizer can significantly improve the total tomato yield.According to the correlation analysis,the contents of calcium,magnesium and sulfur in tomato fruit were positively correlated with soluble sugar content.The contents of calcium,magnesium and sulfur in the soil were positively correlated with the content of vitamin C,and negatively correlated with organic acids.Increasing the amount of sulfur in the soil will increase the yield of tomato.