Fertilizer

Fertilizer is any substance, natural or synthetic, applied to soil or plant tissue to supply one or more of the nutrients essential for plant growth. Nutrients are generally split into three groups: primary macronutrients — nitrogen (N), phosphorus (P), and potassium (K), combined in "NPK" ratios such as 19-19-19 or 00-52-34 to match a crop's growth stage; secondary nutrients — sulphur, magnesium, and calcium, needed in smaller but still substantial amounts; and micronutrients — zinc, boron, copper, and iron, required only in trace quantities but capable of limiting yield entirely when deficient. Micronutrients are further split by form: simple inorganic salts like zinc sulphate are cheaper and release quickly but can bind to soil and become unavailable at high pH, while chelated forms — bound to an organic molecule such as EDTA — stay soluble and plant-available across a wider pH range, which is why chelated zinc, copper, ferrous, and boron variants exist alongside their sulphate counterparts on this page. Choosing the right combination depends on soil test results, the crop's growth stage, and whether the deficiency is being corrected through the soil or via a foliar spray.