Study on release characteristics of matrix-based zinc sulphate controlled release fertilizers

The studies were conducted for the release characteristics of matrix-based zinc sulphate-controlled release fertilizer (CRF). The parameters of the study were fractional fertilizer, fraction of binder, matrix particle size and pellet diameter. Results showed that the release period found to be more for higher fractional fertilizer, pellet diameter; smaller the matrix particle size, moderate amounts of binder release period increases. Based on Fick’s second law of diffusion, models were developed for predicting the mass transfer rates by diffusion methods. The experimental values were in good agreement with simulated data of the model. The data was studied in three regions-A, B and C regions. In region A, the dissolution rate is linear and for other regions, the rate can be expressed as equations of the developed models.