Magnesium fertilizer is also a kind of nutrient fertilizer that plants lack, and it is also very helpful to the growth of plants. If we use magnesium fertilizer correctly, it can bring a great increase in our crops. Then, the role of magnesium fertilizer And how to use it? What are the precautions for use?
Magnesium is an essential nutrient element for crops, a component of chlorophyll, and can promote photosynthesis; it is an activator of many enzymes, can promote the synthesis of various substances, such as vitamin a, vitamin c, etc., thereby improving the quality of fruits and vegetables; Promote the absorption of phosphorus and silicon by crops, enhance the nutrient metabolism of phosphorus, and improve the disease resistance of crops.
With the application of nitrogen, phosphorus, potassium and other chemical fertilizers, crop yields continue to increase. Magnesium in the soil is consumed more and less supplemented. The phenomenon of magnesium deficiency in crops has appeared in various places. According to relevant information, about 54% of the soil in the country needs to be supplemented with magnesium fertilizer to varying degrees.
How to use magnesium fertilizer
(1) Soil application. Magnesium fertilizer can be used for basal fertilizer, top dressing or foliar spraying. To make base fertilizer, it should be mixed with other chemical fertilizers or organic fertilizers before plowing, or mixed with fine soil and then sprayed separately. Topdressing should be applied early, using furrow application or flushing application with water. The appropriate amount of magnesium sulfate per mu is 10-13 kg per mu to the soil, which is 1-1.5 kg per mu of pure magnesium; after a full application, it can be applied in several crops, not every season.
(2) Foliar spraying. Foliar spraying is carried out in the early and middle stages of crop growth. Different crops and different growth periods of the same crop require different spraying concentrations. The total spraying concentration should be controlled with an aqueous solution of magnesium sulfate, 0.5%-1.0% for fruit trees, 0.2% 0.5% for vegetables, field crops such as rice, Cotton and corn are 0.3%-0.8%, and the amount of magnesium fertilizer sprayed per mu is 50-150 kg.
Precautions for using magnesium fertilizer
1. Consider the effective magnesium content of the soil. The effectiveness of magnesium fertilizer on crops is negatively correlated with the effective magnesium content of the soil. When the soil's available magnesium is less than 25 mg/kg, magnesium can increase the yield of soybeans, peanuts, tea, etc. by 9.8%-40.2%. When the effective magnesium of the soil is less than 50 mg/kg, the application of magnesium fertilizer has the effect of increasing production to varying degrees, increasing by 2.7%-11.2%.
2. Consider the magnesium interaction. The effect of magnesium application is restricted by potassium application in soil. After a large amount of potassium is applied to the soil, it will cause insufficient magnesium supply in the soil. Potassium and magnesium in the soil have a mutual restriction. An appropriate ratio of potassium to magnesium is the basis for high yield and high efficiency. After repeated field experiments, the more suitable potassium and magnesium ratios are 33 for sugarcane, 51 for cassava, 21 for peanut and soybean, 24 for jute and sweet potato, and 17 for watermelon.
3. Consider crop varieties and magnesium fertilizer needs. The yield-increasing effect of magnesium fertilizer is related to the magnesium requirement and sensitivity to magnesium of different crops. Flue-cured tobacco is sensitive to magnesium application, followed by rape and soybeans, and wheat is less sensitive.
4. Choose suitable magnesium fertilizer varieties. Different magnesium fertilizers have different properties and different application effects. The effect of applying fertilizers such as magnesium carbonate and magnesium oxide on the red soil increased the dry matter yield of crops by 76.1% and 87.3%; followed by magnesium sulfate and sepiolite powder, which increased the yield by 31.0% and 22.5%, respectively, and the effect of magnesium chloride was poor.