| abstract |
Process of preparing a solid controlled release urea-formaldehyde fertilizer composition comprising preparing an aqueous mixture of urea, formaldehyde and ammonia, heating the mixture, acidifying the mixture to initiate methylene urea polymerization and heating to complete methylene urea polymerization and dry the reaction products. The process is carried out under conditions such that the majority of polymeric nitrogen present in the final product consists of short chain methylene urea polymers selected from the group consisting of methylene diurea, dimethylene triurea and mixtures thereof. |