Magnesium is the component of plant chlorophyll and phytoalexin, and is the only metal element in chlorophyll molecules. Magnesium plays an important role in photosynthesis. Magnesium ions are activators of various enzymes, which promote the conversion and metabolism of sugars in crops and promote the synthesis of fats and proteins.
Magnesium also promotes the absorption of silicon and phosphorus from crops, thereby increasing crop resistance to diseases. Magnesium also promotes the formation of vitamin A and vitamin C in crops, thereby improving the quality of crops such as fruits and vegetables.
Magnesium fertilizer application method:
Magnesium can be directly used as base fertilizer, top dressing and foliar fertilizer. For example, calcium magnesium phosphate fertilizer and magnesium ammonium phosphate which is slightly soluble in water can be used as the base fertilizer. The application amount can be calculated according to the magnesium content. Generally, the magnesium content per acre is 1 to 1.5 kg.
For example, magnesium oxide and magnesium sulfate can be used as top-dressing fertilizers for crops. The use of magnesium fertilizer for top-dressing needs early application, and it can be applied by ditching or watering. Generally, it is suitable to apply 10~13 kg of magnesium sulfate per mu of land, and generally, 250~500 g of magnesium sulfate can be applied to each fruit tree. After the application of magnesium fertilizer, crops can be reapplied several crops apart, and it is not necessary to apply crops every season.
For example, magnesium nitrate can be used as a foliar spray on crops, mainly for the symptoms of magnesium deficiency caused by root disorders in fruit trees, eggplant, vegetables, and legumes. The commonly used magnesium nitrate content is 1% because of the foliar spray. The effect of fertilizer is not long-lasting, and it should be sprayed several times in order to achieve the effect.
Common magnesium fertilizer varieties and application methods:
Magnesium is commonly used as magnesium magnesium phosphate fertilizer 8% to 20%, magnesium sulphate 10%, about 25% magnesium chloride, dolomite powder 11% to 13%. Acid soil is preferably made of calcium magnesium phosphate fertilizer and dolomite powder, and alkaline soil is preferably magnesium chloride or magnesium sulfate. It can be used as basal fertilizer or top dressing, calculated as Mg, with 1~1.5kg per acre. Citrus and other fruit trees, applied 0.5kg of magnesium sulfate per plant. Magnesium sulfate is a water-soluble magnesium fertilizer, can be used as extra-root fertilizer, spray concentration of 1% to 2%, 50 kg of spray solution.