Sugarbeet yield and quality when substituting compost or manure for conventional nitrogen fertilizer

Authors: Lehrsch, Gary; BROWN, BRADFORD - Retired Non ARS Employee; Lentz, Rodrick; JOHNSON-MAYNARD, JODI - University Of Idaho; Leytem, April

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/8/2014
Publication Date: 12/1/2014
Publication URL: http://handle.nal.usda.gov/10113/60073
Citation: Lehrsch, G.A., Brown, B., Lentz, R.D., Johnson-Maynard, J.L., Leytem, A.B. 2014. Sugarbeet yield and quality when substituting compost or manure for conventional nitrogen fertilizer. Agronomy Journal. 107(1):221-231.

Interpretive Summary: To profitably produce sugarbeet, producers must effectively manage added nitrogen (N), whether it be from conventional fertilizer such as urea or from often readily available and sometimes less expensive organic fertilizer sources like manure or composted manure. Our study’s objective was to determine if equivalent sugarbeet root and sugar yields could be achieved when substituting composted dairy cattle manure or stockpiled manure for conventional N (urea) fertilizer. Treatments at Parma, ID, for 2 years included a control (no N applied), urea (180 lbs/acre of total N, that is, N in both the inorganic and organic forms), compost (972 and 1942 lbs total N/acre), and manure (313 and 626 lbs total N/acre). Treatments at Kimberly, ID, were a control, urea (73 lbs N/acre), compost (360 and 815 lbs total N/acre), and manure (387 and 759 lbs total N/acre). Compost and manure were applied, then incorporated into a Greenleaf silt loam at Parma in fall 2002 and 2003 and a Portneuf silt loam at Kimberly in fall 2002. Sugarbeet was planted the following spring. Parma’s sugar yields, averaged across years and organic fertilizer rates, were 5.46 tons/acre for urea, 5.30 tons/acre for compost, and 5.00 tons/acre for manure, all statistically equivalent. Corresponding one-year sugar yields were about 44% less at Kimberly than Parma. Doubling the organic fertilizer N application rates at Parma increased sugarbeet root yields by 15 to 26% and sugar yields by 12 to 21%. Applying organic fertilizers in place of urea affected neither root nor sugar yields but at one location decreased sugarbeet crop quality, though without hindering sugar recovery. Sugarbeet producers can use either compost or manure to satisfy their crop’s N needs without sacrificing sugar yield.

Technical Abstract: To profitably produce sugarbeet (Beta vulgaris L.) by maximizing recoverable sucrose, producers must effectively manage added nitrogen (N), whether it be from inorganic sources such as urea or from often readily available and sometimes less expensive organic sources such as manure or composted manure. Our multi-site study’s objective was to determine if equivalent sugarbeet root and sucrose yields could be achieved when substituting composted dairy cattle manure or stockpiled manure for conventional N (urea) fertilizer. Treatments at Site 1 (Parma, ID), for 2 y included a control (no N applied), urea (202 kg N/ha), compost (1089 and 2175 kg total N/ha), and manure (350 and 701 kg total N/ha). Treatments at Site 2 (Kimberly, ID), were a control, urea (82 kg N/ha), compost (403 and 913 kg total N/ha), and manure (433 and 850 kg total N/ha). Compost and manure were applied, then incorporated into two silt loams, a Greenleaf (Xeric Calciargid) at Parma in fall 2002 and 2003 and a Portneuf (Durinodic Xeric Haplocalcid) at Kimberly in fall 2002. Sugarbeet was planted the following spring. Site 1’s sugarbeet sucrose yields, averaged across years and organic N source rates, were 12.24 Mg/ha for urea, 11.88 Mg/ha for compost, and 11.20 Mg/ha for manure, all statistically equivalent. Corresponding one-year sucrose yields, still equivalent, were ca. 44% less at Site 2 than 1. Doubling the organic N application rates at Site 1 increased sugarbeet root yields by 15 to 26% and sucrose yields by 12 to 21%. Applying organic amendments in place of urea affected neither root nor sucrose yields but at one location decreased sugarbeet crop quality by increasing brei nitrate and conductivity, though without hindering sucrose recovery. Sugarbeet producers can use either compost or manure to satisfy their crop’s N needs without sacrificing sucrose yield.