|Cook, Kimberly - Kim|
Submitted to: North Central Extension Industry Soil Fertility Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/18/2013
Publication Date: 11/20/2013
Citation: Ritchey, E.L., Cook, K.L., Gray, J.L. 2013. The use of organic soil amendments for winter wheat production in Kentucky. North Central Extension Industry Soil Fertility Conference Proceedings. on-line at http://www.ipni.net/ipniweb/conference/ncisfc.nsf. 29:69-76. Interpretive Summary:
Technical Abstract: Most animal manures are land-applied in the fall and spring after crops have been harvested or prior to planting. Surface application of manures in the fall have more potential for nitrogen (N) loss when applied to fallow land compared to land cropped to winter wheat. This study was conducted to determine the N availability of fall applied organic fertilizers and resulting wheat grain yields compared to urea-N fertilizer. The effects of three organic fertilizer sources and rate on wheat yield and nitrogen availability coefficients (AC) were compared to urea-N on a Zanesville silt loam soil following corn. Composted swine manure (CSM), poultry litter (PL), and a processed biosolid - Louisville Green (LG) were applied at rates of 100, 150, and 200 lbs total N/A. Commercial fertilizer (CF) was split applied in the spring at rates of 0, 30, 60, 90, and 1200 lb N/A. Grain yield was collected and analyzed. Overall yields were higher in 2012 than 2011. In 2011, LG appeared to be the superior organic product based on yield response data, but N availability was = 20.7% of urea-N for all LG treatments. Both PL and LG had higher yields and AC in 2012, but considerable variation within sources (35 – 40% differences in AC) was present. Yields and AC for CSM were the lowest of the three sources and often not different than the untreated check. Considerable variation within organic sources, coupled with low AC and wheat grain yields, suggest that adequate N is not being supplied to the plant at these rates and that supplemental inorganic N should be considered to maximize wheat yield.