Advances in Controlled Release Fertilizers: Cost-Effective Coating Techniques and Smart Stimuli-Responsive Hydrogels

To meet the needs of a rapidly expanding global population, farmers will need more fertilizers than ever before to maintain a steady supply of affordable, nutritious food. The formulation of controlled release fertilizers (CRF) to synchronize nutrient release according to the demand of plants has emerged as a viable solution to the current problems associated with the poor nutrient usage efficiency of fertilizers. Yet, the greatest obstacle that still stands in the way of broad use of CRF in agriculture is their expensive manufacturing costs. The first section of this analysis focuses on broad topics related to CRF. Afterward, the differences between several cost-effective raw materials and some of the production techniques used to make CRF are examined. Furthermore, the emerging field of "smart" coating materials, such as stimuli-responsive coatings, which can accurately tailor nutrients delivery to the demands of the vegetation, is discussed, and the most important research work that could lead to their extensive use in agriculture is pointed out. The purpose of this review is to provide a strong assessment of CRF's development over the past several years by highlighting innovations and providing in-depth analysis of prevailing patterns to better understand the future of agriculture.