Abstract: Low molecular weight urea-formaldehyde reaction products are provided. Such products exhibit cold water solubility. They find use as a sustained nitrogen-release source for animals and plants. A three-stage process is provided for preparing the reaction products. The first stage comprises reacting urea and formaldehyde in an alkaline, alcoholic solution. Then the solvent is distilled off to form a melt. In the final stage the melt is polymerized to form the cold water soluble, low molecular weight reaction product.