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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #227757
Title: Application of anaerobically digested biosolids to dryland winter wheat: 2006-2007 results

Author
item BARBARICK, K - COLORADO STATE UNIVERSITY
item Ippolito, James
item GOURD, T - COLORADO STATE UNIVERSITY
item MCDANIEL, J - COLORADO STATE UNIVERSITY

Submitted to: Colorado State University Technical Report
Publication Type: Experiment Station
Publication Acceptance Date: 5/1/2008
Publication Date: 5/1/2008
Citation: Barbarick, K.A., Ippolito, J.A., Gourd, T., Mcdaniel, J.P. 2008. Application of anaerobically digested biosolids to dryland winter wheat: 2006-2007 results. Colorado State University Technical Report TR08-09. p. 1-14.

Interpretive Summary:

Technical Abstract: The application of biosolids to lands in EPA Region 8 is the major method of biosolids disposal, with 85% of the material being reused. This disposal method can greatly benefit municipalities and farmers by recycling plant nutrients in an environmentally sound manner. Our long-term biosolids project, now in its twenty-sixth year, has provided valuable information on the effects of continuous biosolids applications to dryland winter wheat in Adams County near Bennett, CO. Biosolids were applied at 0, 1, 2, 3, 4, and 5 dry tons per acre, and compared to N fertilizer applied at 0, 20, 40, 60, 80, and 100 lbs per acre. Grain yields were above the Adams County average yield of 30 bu per acre, although biosolids had no effect on grain yield or protein content. On the average, the estimated net return to biosolids was greater than N fertilizer application. The recommended 2 dry tons biosolids per acre rate produced an economic return greater than that of the 40 lbs N per acre treatment. This trend was similar to previous findings where biosolids usage provided a greater economic advantage. Increasing biosolids rate caused an increase in grain Zn concentration and straw Cu and Zn. The increase in grain Zn content due to increasing biosolids application can be viewed as positive since this soil is Zn deficient. All grain and straw metal concentrations were well below the levels considered harmful to livestock, and all findings were relatively similar to previous years. The recommended 2 dry tons biosolids per acre application rate did not affect nitrate-N throughout the profile as compared to either the control or the 40 lbs N per acre rate. We expect increases in grain yield and protein content, and no increase in soil nitrate-N, when we apply biosolids or N fertilizer at recommended rates on N-deficient soils. During most growing seasons biosolids could supply slow-release N, P, Zn, and other beneficial nutrients. We continue to recommend a 2 to 3 dry tons biosolids application per acre. Previous growing season results show that 1 dry ton biosolids A-1 is equivalent to 16 lbs N per acre. These approximations could help in planning long-term biosolids applications to ensure optimum crop yields along with environmental protection.