Although trace element fertilizers are used in small amounts, they are indispensable for crop growth

Trace element fertilizers refer to fertilizers whose main nutrients are trace elements such as iron, manganese, zinc, copper, boron, molybdenum and chlorine. Although crops need only very small amounts of these nutrients, they take part in photosynthesis, enzyme activity and the transformation of substances within the plant. Once their supply is insufficient, plants show obvious symptoms such as yellowing leaves, deformed fruit and flowers that fail to set fruit.

Common types include boron fertilizer, zinc fertilizer, iron fertilizer, molybdenum fertilizer, manganese fertilizer and copper fertilizer. In terms of formulation, they can be divided into two main categories: inorganic salts and chelated forms. Chelated products have better nutrient stability, and the crop's absorption and utilization rate is relatively higher. Varieties with good water solubility are also convenient for foliar spraying and application with irrigation water.

Application methods include basal soil application, seed dressing and seed soaking, and foliar spraying. These fertilizers are used in small amounts and take effect fairly quickly, but more is not always better; excessive application can easily cause crop toxicity and also increase the burden on the soil. In alkaline soil, elements such as iron, zinc and manganese are easily fixed, so foliar spraying is often more direct and effective than soil application.

Before use, it is advisable to determine whether there is a nutrient deficiency based on soil testing and plant growth, so as to supply exactly what is lacking and avoid blind application. At the same time, attention should be paid to compatibility issues: some trace element fertilizers react when mixed with phosphate fertilizer and other fertilizers, reducing fertilizer efficiency, so the relevant incompatibilities should be understood before mixing. When spraying on leaves, the concentration should also be well controlled, and spraying should preferably be done in the morning or evening to reduce the risk of fertilizer damage.