If confirmed by laboratory results, and despite the entailed cost, gypsum application is necessary and must be a priority among farming practices. Essentially, increased calcium concentration in the soil solution in any way, such as by gypsum application, can cause formation of insoluble compounds containing phosphorus or micronutrients thus making them unavailable to plants. That is why it is necessary to consider the following points before applying gypsum:
- Gypsum application rate must be decided based on laboratory results. If very high application rates are required, the recommended amount should be applied in 2-3 years to increase application efficiency and reduce costs in addition to preventing severe reductions in soil fertility, especially soil phosphorus loss.
- Foliar application of compounds containing phosphorus and micronutrients in orchards after applying large amounts of gypsum can considerably reduce the risk of deficiency of these nutrients.
Considering the chemical properties of many agricultural soils and irrigation water in agricultural fields, gypsum application can be one of the priorities among soil amendments and yield increases resulting from its application may be significant. Of course, as mentioned above, gypsum application must be under the supervision of experienced specialists and its application rate should be determined by considering laboratory results in order to achieve the best results.