Firstly, the main role of magnesium fertilizer

Magnesium is mainly present in chlorophyll, phytin and pectin, and plays an important role in photosynthesis. Magnesium ion is an activator of various enzymes, which promotes sugar conversion and metabolism in the body, and promotes the synthesis of fats and proteins. Application of magnesium to oil crops can increase its oil content, and magnesium can also promote the absorption of silicon by crops. The application of magnesium fertilizer in magnesium-deficient soils can increase its oil content, and magnesium can also promote the absorption of silicon by crops. Applying magnesium fertilizer to magnesium-deficient soil can improve the effect of phosphate fertilizer.

Secondly, the application technology of magnesium fertilizer

1. Soil, crop and magnesium fertilizer application. The magnesium content in the soil is mainly affected by the parent material and weathering conditions. It is located in a high temperature and rainy zone, and the total magnesium content in the soil is low. When the exchangeable magnesium (Mg2 +) content in the soil is less than 50 mg / kg, the effect of increasing yield by applying magnesium fertilizer is obvious. Potassium-rich soils and areas where large amounts of potassium have been applied for a long time, as well as the application of lime in acid soils, can easily induce soil physiological Mg deficiency. Cotton, fruit trees and other economic crops are more sensitive to magnesium fertilizers, and their demand is greater. The demand for magnesium in rice is less than sugarcane, potato, corn, citrus and other crops. The increase in production is unstable.

2. Magnesium fertilizer varieties and applications. Commonly used magnesium fertilizers contain 8% -20% of calcium magnesium phosphate, about 10% of magnesium sulfate, about 25% of magnesium chloride, and 11% -13% of dolomite powder. It is better to apply calcium magnesium phosphate fertilizer and dolomite powder to acid soil, and to apply magnesium chloride or magnesium sulfate to alkaline soil. It can be used as basal fertilizer or topdressing fertilizer, with 1-1.5kg per acre calculated based on Mg. For citrus and other fruit trees, 0.5 kg of magnesium sulfate was applied to each plant. Magnesium sulfate belongs to water-soluble magnesium fertilizer, which can be used as topdressing fertilizer outside. The spraying concentration is 1% -2%, and the spraying solution is about 50kg per mu.