Foliar fertilizer application must be tailored to the specific problem
The effectiveness of phosphate fertilizer application depends both on the total amount of available phosphorus in the soil and on the soil properties; for example, some soils can promote the dissolution of sparingly soluble phosphates, while other soils can cause the fixation of soluble phosphates. Generally, after phosphate fertilizer is applied to the soil, it quickly combines with iron, calcium and aluminum in the soil...
When crops show deficiency symptoms. Usually during field production, some crops often exhibit deficiency symptoms of certain elements. At this time, using foliar fertilization gives better results and higher utilization efficiency than applying fertilizer to the soil.When the absorption capacity of crop roots declines. In the late growth stage of crops, the roots often show declining vitality and reduced fertilizer uptake capacity. At this time, if fertilizer is to be applied to the crops, foliar spraying is preferable.
When crop growth is affected by an adverse environment. When the soil environment is unfavorable for crop growth, such as when there is too much or too little water, drought, or when the soil is too acidic or too alkaline, foliar spraying is the way to quickly supplement nutrients and meet the needs of growth and development.
When soil fertilization is difficult to carry out. First, for the application of trace elements, foliar spraying is often used. Second, for crops covered with plastic film, when the base fertilizer application rate is insufficient, soil topdressing is difficult to carry out; at this time, foliar spraying is preferable to supplement nutrient needs.