Preparation And Nutrient Release Performance Of Biodegradable Coated Fertilizer

As the population grows and urbanization quickens,agricultural output encounters more and more difficulties.The efficiency and quality of agricultural production must be continually improved in order to meet the expanding human population’s demand for food.Among these,slow-release fertilizers have garnered a lot of attention in contemporary agriculture because they are a novel form of fertilizer with the ability to control the rate of nutrient release and deliver nutrients continually.Traditional slowrelease fertilizers typically have non-degradable coating components,which means that once nutrients are released,the coating materials linger in the soil and contaminate it.People have started looking for environmentally responsible solutions to this issue,and biodegradable polymers have emerged as a key option.In order to achieve this,a variety of multilayer coated slow-release fertilizers were created in this work employing microcrystalline wax for the sealing layer and biodegradable coating materials cellulose acetate(CA)and polycaprolactone(PCL),respectively.This type of fertilizer uses biodegradable coating materials,and once the nutrient release is complete,the film layer will naturally degrade and won’t stay in the soil for a long time,reducing environmental pollution and offering an eco-friendly approach to agricultural production.First,multilayer coated urea was created using the impregnation process,with urea serving as the core and CA and PCL acting as the outside layers.By altering the CA and PCL concentrations,the coating effect could be managed.Investigations into the impact of polymer layer concentration on the slow-release performance of encapsulated urea revealed that as polymer layer concentration increased,the rate of nutrient release decreased;the increase in PCL concentration contributed more to the slow release of nutrients than the increase in CA concentration.Meanwhile,the slow-release curves were measured in high temperature,low temperature,acidic,and alkaline environments,respectively,to verify the slow-release performance of the coated urea in various environments.It was discovered that the rate of nutrient release was further slowed down in low temperature environments,and the rate of nutrient release was increased in high temperature,acidic,and alkaline environments,but the good slow-release performance.Additionally,glutaraldehyde was employed as a cross-linking agent to modify CA in order to increase the slow-release performance of the encapsulated urea in acidic and alkaline environments in order to have a better applicability in various acidic and alkaline soils.By varying the glutaraldehyde concentration and reaction temperature,the best conditions for the reaction were investigated.The findings demonstrated that the modified CA had the lowest cumulative release of nutrients in both acidic and alkaline environments,the worst hydrophilicity,and the best thermal stability when produced at a reaction temperature of 45 °C and a glutaraldehyde ratio of 2wt %.It is a hopeful indicator for wider applications since the rate of nutrient release from CAmodified periplasmic urea was much slower in both acidic and alkaline settings.