Using Manure From Cattle Fed Dried Distillers' Grains with Solubles (DDGS) as Fertilizer: Effects On Nutrient Accumulation in Soil and Uptake by Barley Forage.

With increasing production of ethanol and availability of dried distillers’ grains with solubles (DDGS) as feed, we need a better understanding of the impact of DDGS manure on crop production and the environment. The objective of this study was to investigate nutrient uptake by barley forage and accumulation of N and P in soil amended with manure from feedlot cattle fed with a diet containing DDGS. The experiment was conducted in a growth chamber, with barley (Hordeum vulgare) seeded into sandy textured Aridic Haploboroll soil amended at five levels with manure from DDGS-fed cattle (DDGS manure) and from those not fed this by-product (control manure). Manure had been applied to the soils at rates equivalent to 30, 60, 120 and 180 Mg ha^-1 yr^-1 (wet weight). Crops were grown and harvested six times. Preliminary analysis of results indicates that barley forage yields were higher in DDGS manure treatments than the control. All resulted in similar increases in plant total P (TP) content while plant TN content responses were not consistent. Soil TP and available P contents were higher with DDGS manure treatments than in soils amended with control manure. Increases in soil total N (TN) and available N contents were similar with both types of manure. This study clearly demonstrates that inclusion of DDGS in the diet of cattle increases the amount of P that is excreted into the environment and its accumulation in the soil. Thus, manure management practices should be adjusted to account for compositional changes in manure so as to minimize any negative impact on the environment.