Abstract: A process for the preparation of a slow-release fertilizer comprising the steps of:(a) grinding a first volume of peanut hulls to a particle size of 1/32 to 1/4 inch and a second volume to 1/8 to 1/2 inch,(b) treating said first a volume of hulls with an equal volume of 2N (normal) nitric acid for 30 minutes at 121 degrees C. and 15 p.s.i. pressure to extract and solubilize the liqueous material from the hulls,(c) adding 1 volume of 1 normal solubilized sodium hydroxide to 2 volumes of said second volume of peanut hulls and heating and stirring said mixture until said nutrients are solubilized,(d) heating said second volume of peanut hulls and sodium hydroxide with steam and at a temperature of 121 degrees C. and pressure of 15 p.s.i.