Magnesium is an essential macronutrient for plants and plays a crucial role in plant metabolism and growth. As we know, when plants suffer from magnesium deficiency, the most prominent symptoms are reduced chlorophyll content and leaf yellowing. Because magnesium exhibits high mobility in the phloem, deficiency symptoms typically first appear on older leaves and gradually spread to newer leaves. When magnesium is deficient, plants tend to be stunted and grow slowly. In dicotyledonous plants, magnesium deficiency causes interveinal chlorosis, which progressively changes from pale green to yellow or white. Additionally, irregular brown or purplish-red spots or stripes may develop across the leaves. Due to the hot and humid climate in southern China’s red soil regions, magnesium-containing minerals undergo intense weathering, leading to heavy leaching of magnesium from the soil and consequently weakening the soil’s ability to supply adequate magnesium. As a result, many crops in these areas exhibit symptoms of magnesium deficiency. Field trial results involving 236 crop species across 22 categories—including economic crops, oilseed crops, grain crops, vegetable crops, and fruit crops—demonstrate that applying magnesium fertilizer to the soil can significantly enhance both the yield and quality of these crops. Now, let’s continue following along... Calcium-magnesium fertilizer origin Let’s take a look at how to apply it.
1. The soil should have a certain magnesium content: the effectiveness of magnesium fertilizers on crops is negatively correlated with the soil’s available magnesium content. When the available magnesium content in the soil falls below 25 mg/kg, yields of soybeans, peanuts, and tea can increase significantly by 9.8% to 40.2%. When the available magnesium content in the soil is lower than 50 mg/kg, applying magnesium fertilizer can boost yields by 2.7% to 11.2%.
2. Potassium-Magnesium Interaction Effect: The effect of magnesium application is limited by the level of potassium applied to the soil. After applying large amounts of potassium to the soil, the soil may not provide sufficient magnesium, leading to a mutual restriction between potassium and magnesium in the soil. Maintaining an appropriate potassium-to-magnesium ratio is essential for achieving high yields and efficient production. Based on repeated field trials, the optimal potassium-to-magnesium ratios are as follows: 3.3 for sugarcane, 5.1 for cassava, 2.1 for peanuts and soybeans, 2.4 for jute and sweet potatoes, and 1.7 for watermelon.
The above is Calcium-magnesium fertilizer origin The editor has briefly introduced some basic knowledge about magnesium—hopefully, you’ll find it helpful.