An evaluation of the design and performance of a biobased carrier made from distillers grains for fertilizer applications

Ruth Lauren Pinto, Purdue University


The major use for distillers dried grains with solubles (DDGS), a co-product of dry-grind ethanol production, is as livestock feed. The rapid growth of the fuel ethanol industry in the last few years has caused an increase in the supply of DDGS beyond its demand as a feed ingredient. A new value added product, biobased carriers from DDGS, has been invented to create a new market for DDGS. One possible use of these carriers would be to deliver fertilizers. This research investigates the design and performance of DDGS as a biobased carrier for slow release fertilizer applications. Results show that DDGS and fertilizer can successfully be granulated together and coated with a biobased polymer, chitosan, to form granules of an appropriate size range for lawn and garden applications. Physical property testing revealed that DDGS based slow release fertilizer granules exhibited lower bulk densities, higher porosity and moisture content, and similar flowability and resistance to attrition than commercially available slow release fertilizers. A nitrogen leaching test was carried out by applying fertilizer granules to perennial ryegrass in a greenhouse. The amount of nitrogen which leached from the polymer coated DDGS based fertilizer granules was 6% of the total amount applied after 50 days. For slow release commercially available fertilizers, nitrogen leaching ranged from 0.5% to 2%, indicating that the DDGS based granules were not as effective in slow release properties as the commercial fertilizers. More research work is proposed to improve on the measured performance of DDGS carriers for slow release fertilizers.




Ileleji, Purdue University.

Subject Area

Agricultural engineering|Public health

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