Magnesium (Mg)
A secondary macronutrient at the center of every chlorophyll molecule. Without adequate magnesium, chlorophyll cannot form and grass turns yellow. Magnesium deficiency is more common in acidic, sandy soils with high rainfall.
Magnesium is the central atom in the chlorophyll molecule — making it critical to photosynthesis and the green color of grass. It also activates many enzymes involved in plant metabolism.
Deficiency signs: Interveinal chlorosis — yellowing between the leaf veins while the veins themselves remain green. Older leaves show symptoms first.
Application: Dolomitic lime (calcium magnesium carbonate) is a common source of both calcium and magnesium. Epsom salt (magnesium sulfate) is sometimes used as a quick liquid application — 1–2 tablespoons per gallon of water as a foliar spray.
More on Micronutrients
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