Zinc oxide can be used as base fertilizer, topdressing, foliar spraying and seed soaking.

Zinc oxide, also known as zinc oxide powder and zinc white. The effective zinc content is 78%. Zinc oxide is white powder or hexagonal crystal. Odorless, tasteless and Sandy. It turns yellow after heating and white again after cooling. Soluble in acid, alkali, ammonium chloride and ammonia, insoluble in water and alcohol. Zinc oxide  is an amphoteric oxide, which is easy to absorb carbon dioxide from the air to produce zinc carbonate, and can be reduced to metal zinc by carbon or carbon monoxide. The symptoms of crop zinc deficiency mainly occurred in the early stage of growth, mainly manifested as internode shortening, short plants, smaller and deformed leaves, and chlorotic stripes or white lines, forming leaf clusters. When tomato is short of zinc, the plant grows thin, the leaves are twisted, and the yellow spots appear on the surface. Then the yellow spots gradually expand, the whole plant turns yellow, the branches and leaves droop and scorch, and the results are small. When cucumber is zinc deficient, the plant grows poorly, the edges of old leaves turn yellow and zoom, and gradually expand inward in an irregular manner. Small yellow spots appear on the leaf surface. The results are short and thick. The peel forms wide green and narrow white stripes, and the green of the stripes is shallow. When eggplant is short of zinc, the plant grows short, the top leaves are thin and long, both sides of the leaves roll up, and the lower leaves lose a lot of green, or even completely green. Zinc fertilizer  is a material with marked amount of zinc to provide plant nutrients as its main effect. The commonly used zinc fertilizers are zinc plus selenium, zinc sulfate heptahydrate and zinc sulfate monohydrate. Basic zinc sulfate, zinc chloride, zinc oxide, zinc sulfide, zinc phosphate, basic zinc carbonate, zinc vitreous, lignin zinc carbonate, zinc naphthenate emulsion and chelated zinc can be used as zinc fertilizer. The latter three are organic zinc fertilizers, which are easily soluble in water. Zinc fertilizer can be used as basal application, topdressing, seed soaking, seed dressing and spraying. Generally speaking, it can be used as foliar fertilizer spraying effect. Zinc fertilizer is applied to zinc sensitive crops, such as corn, rice, peanut, soybean, sugar beet, kidney bean, fruit tree and tomato. Application on zinc deficient soil: it is better to apply Zinc Fertilizer on zinc deficient soil, and there is no need to apply Zinc Fertilizer  on non zinc deficient soil.

Zinc is an essential nutrient element for crops. Zinc can promote the synthesis of indoleacetic acid in crops, so as to promote the growth of stem ends, young leaves and roots; Zinc is the component and activator of many enzymes in crops, which participates in the respiration of crops and the metabolism of many substances; Zinc is closely related to the synthesis of crop protein, has a significant impact on the formation of crop chlorophyll and photosynthesis, is conducive to the stability of crop root cell membrane and cell structure and the integrity of function, plays a protective role on root surface and root cell membrane, can enhance the stress resistance of crops, affect the absorption of phosphorus by crops, and regulate the balanced utilization of phosphorus in crops. If zinc is deficient, it will have adverse effects on the normal growth of crop roots, stems and leaves.

Zinc oxide  is a commonly used zinc fertilizer. It can be used as base fertilizer, topdressing, foliar spraying and seed soaking. Due to the low solubility and poor mobility, the fertilizer effect is long. Once applied, it can be effective for a long time, but the zinc absorbed by the crops in the current season is less. It is often mixed into suspension to dip in the root. During seed soaking and foliar spraying, because zinc oxide  is insoluble in water, non-ionic wetting agent is required to prepare suspension. At the same time, in order to ensure the effect, the application amount is slightly higher than that of zinc sulfate. Rice seeds can be treated with 1.0% ~ 1.5% zinc oxide  during seed germination (1.0% zinc oxide for dry seeds and 1.5% zinc oxide for wet seeds).