Distillers grain could be a good source of fertilizer for some crops, according to research at North Dakota State University.

Wet distillers grain and condensed distillers solubles (sometimes referred to as “syrup”) are organic byproducts of ethanol production from corn. Scientists at the Carrington Research Extension Center have been testing whether wet distillers grain and condensed distillers solubles are a viable source of phosphorus for corn and spring wheat crops. They applied those byproducts, as well as triple superphosphate, a fertilizer with a high P content, at various levels.

Here’s what they found:

• In 2016, corn yield increased by about 4 bushels per acre when phosphorus was applied at the rate of 40 pounds per acre. Wheat yield increased by 2 bushels per acre when P was applied at the rate of 40 pounds per acre and by 5 bushels when P was applied at the rate of 80 pounds per acre.

• In 2016, corn yields were significantly higher from applications of wet distillers grain than the other P sources. In 2015, condensed distillers solubles produced much higher yields.

• Wheat yield also increased significantly with wet distillers grain applications, compared with triple superphosphate. Applications of condensed distillers solubles produced higher yields than triple superphosphate, but not as high as wet distillers grain.

“These results indicate that there are nutrient benefits to crops from using distillers grain as a source of crop nutrients,” says Jasper Teboh, NDSU soil scientist.

He speculates that other nutrients in distillers grain, such as sulfur, may have enhanced the effect of the wet distillers grain and condensed distillers solubles. Also, the yield gains from the distillers grain may also be linked to enhanced microbial activity. However, the scientists aren’t sure why the yields from the wet distillers grain were better than from the condensed distillers solubles in 2016 but not in 2015.

Economics
Teboh cautions that the use of distillers grain may not be feasible for all producers.

“Preliminary assessment of net returns to farmers suggests that only producers farming within close proximity to ethanol plants are more likely to benefit from using distillers grains as fertilizer sources because of transportation costs,” he says. “In early 2016, condensed distillers solubles cost 5 per ton and wet distillers grain cost $30 per ton. It cost about $25 per ton for an application to haul and apply both products with 25 miles of an ethanol plant.”

Visit the Carrington Research Extension Center’s website for more information about this research.

Source: NDSU Extension Communications