Location: Northwest Irrigation and Soils ResearchTitle: Biochar and manure effects on nitrogen nutrition in silage corn Author
Submitted to: Popular Publication
Publication Type: Popular Publication
Publication Acceptance Date: 4/24/2015
Publication Date: 6/12/2015
Citation: Lentz, R.D., Ippolito, J.A., Spokas, K.A. 2015. Biochar and manure effects on nitrogen nutrition in silage corn. Nutrient Digest. 7(2):1,3-4.
Technical Abstract: Amending soil with biochar may be a means of sequestering atmospheric CO2 and improving soil quality, but few multiyear field studies have examined the impacts of a one-time biochar application in an irrigated, calcareous soil. Four treatments were applied in the fall 2008: dairy manure (18.7 tons/ac dry wt.); hardwood-derived biochar (10 tons/ac dry wt.); combined biochar and manure; and no amendments (control). We measured net N-mineralization and soil greenhouse gas emissions (CO2, CH4, and N2O) from late spring to fall, corn silage yields, and crop N uptake each year. The influence of biochar and manure on silage yield changed in the years following application. Biochar increased corn yields slightly (5%) in 2009, decreased yields by 14% in 2010, and had no effect in 2011. Conversely, manure had no affect on yields in 2009, but increased yields substantially in 2010 (33%) and again slightly in 2011 (7%). The NH4-N concentrations in plot soils increased relative to NO3-N in late summer 2010 compared to other times. We hypothesized that the predominance of NH4-N in soil, combined with biochar’s increased capacity to sequester NH4-N in 2010, resulted in reduced crop N uptake and yields in biochar plots. The biochar-only treatment also demonstrated a potential to minimize CO2-C and N2O-N gas emissions in these calcareous soils. The combined biochar-manure treatment more effectively utilized the two soil amendments as it eliminated potential yield reductions caused by biochar and maximized manure net N mineralization potential.