Effect Of Magnesium Fertilization On Yield And Quality Of Processed Tomatoes

Object:Magnesium content in calcareous soil is relatively rich,and crops’demand for magnesium can generally be met.As a kind of crops with high demand for magnesium,processing tomatoes like magnesium and are sensitive to magnesium,it is necessary to ensure the supply of magnesium.In recent years,magnesium deficiency often occurs in the planting process of processed tomatoes in Xinjiang,which seriously affects the yield and quality of processed tomatoes.In this experiment,the effects of magnesium fertilizer on nutrient absorption,yield and quality of processed tomatoes were discussed by discussing the relationship between magnesium fertilizer dosage,application mode,drip application times and distribution ratio,and the suitable fertilization scheme was selected to provide reference for magnesium fertilizer application and processing tomato production in calcareous soil.Methods:This experiment was conducted in a field plot in 2020-2022:1.Magnesium fertilizer application rate test:set four magnesium fertilizer application rates:0,225,450and 900 kg/hm² magnesium sulfate,which are represented by CK,JS225,JS450 and JS900 respectively.2.Test of application mode of magnesium fertilizer:five treatments were set:（1）No magnesium fertilizer（CK）;（2）basal application of 225 kg/hm² magnesium sulfate（JS225）;（3）basal application of 450kg/hm² magnesium sulfate（JS450）;（4）drip 225 kg/hm² magnesium sulfate（DS225）;（5）Drip 450 kg/hm²magnesium sulfate（DS450）.3.Experiment on the number and proportion of magnesium fertilizer drops:Six treatments were set in the experiment:（1）Fertilizing for three times+applying 50%magnesium sulfate at seedling stage（DS3O）;（2）Fertilizing for three times and applying 50%magnesium sulfate at flowering stage（DS3M）;（3）Fertilizing for three times+applying 50%magnesium sulfate at the swelling stage（DS3E）;（4）Fertilizing for 6 times and applying 50%magnesium sulfate at seedling stage（DS6O）;（5）Fertilizing 6 times+applying 50%magnesium sulfate at flowering stage（DS6M）;（6）Fertilize for 6 times and apply 50%magnesium sulfate in the expansion period（DS6E）.Results:（1）After basal application of magnesium fertilizer,the plant height,stem diameter,dry matter weight and chlorophyll content of processed tomatoes were increased,the SPAD peak value was increased and the peak duration was prolonged;Compared with CK treatment,the absorption and accumulation of nitrogen,phosphorus,potassium,calcium and magnesium by processed tomatoes increased.When the basal application rate is 450 kg/hm²,the yield is the highest,the quality is the best and the economic benefit is the highest.（2）Different application methods of magnesium fertilizer can improve the electrical conductivity,available potassium content and water-soluble magnesium content in soil,and reduce the soil p H value.The content of water-soluble magnesium in soil is higher and lasts longer under the drip application of magnesium fertilizer.Drip application of magnesium fertilizer can further increase the contents of nitrogen,potassium and magnesium in different organs of processed tomatoes and reduce the content of calcium.The dosage of magnesium fertilizer was 450 kg/hm^2,and the plant height,stem diameter,SPAD value,chlorophyll content and dry matter accumulation of processed tomatoes were significantly improved by drip application compared with basal application.（3）The dry matter quality of processed tomato plants was significantly improved when magnesium fertilizer was applied 6 times and the proportion was at the fruit expansion stage.The chlorophyll content of processed tomato leaves was increased at flowering stage and fruit expansion stage.Under the same drip application times,the distribution ratio of flowering stage and fruit expansion stage can significantly increase the content of nitrogen and magnesium in fruit and promote the transfer of nitrogen to fruit.Under the same distribution ratio of magnesium fertilizer,increasing the number of drip application significantly increased the magnesium content of fruit.（4）When the distribution ratio is fruit expansion stage,the yield of processed tomato can be significantly improved when magnesium fertilizer is applied 6 times.Under the same distribution ratio,the content of vitamin C in processed tomato fruit was significantly increased when it was dripped for 6 times.（5）When the optimum magnesium fertilizer application amount is 450 kg/hm²,6 times of drip application and the proportion is the fruit expansion stage,the processed tomato has the highest yield and the best quality.Conclusion:Compared with basal application of magnesium fertilizer,drip application of magnesium fertilizer in calcareous soil can significantly promote the growth of processed tomatoes,increase the absorption and accumulation of nitrogen and magnesium,and improve fruit yield.Under the same distribution ratio,increasing the number of drip application can significantly improve the fruit yield and magnesium content;Under the same drip application times,the distribution ratio of flowering stage and fruit expansion stage can significantly improve the dry matter accumulation,chlorophyll content in leaves,yield and vitamin C content.When the recommended dosage of magnesium fertilizer is 450 kg/hm²,applied 6times and the distribution ratio is at the fruit expansion stage,the effect is the best,which significantly promotes the growth,nutrient content,yield and quality of processed tomatoes.