Dynamic of Water Absorption in Controlled Release Fertilizer and its Relationship with the Release of Nutrient

Controlled release fertilizer (CRF) is a prominent green technology that helps to reduce the adverse effect of fertilizer on the environment. A good CRF is expected to synchronize with the nutrient uptake of plants along the crop duration. The water absorption which related to the delay of nutrient release also plays an important role in order to produce a good CRF. This work studied the water absorption in the coating and in the fertilizers using weighing technique. Moreover, the relationships between the absorption processes with the release of nutrient were also pointed out and compared to those in literature. Results showed that water penetration in the coating took place sooner and faster than that in the fertilizers. And, the lag time in nutrient release profile should be linked to the water infiltration in the coating rather than that in fertilizers. Moreover, the absorbency curve followed a first-order kinetic and was similar to cited literature.