Nitrogen dynamics following field application of biochar in a temperate North American maize-based production system

Background and aims Biochar additions to tropical soils have been shown to reduce N leaching and increase N use efficiency. No studies exist verifying reduced N leaching in field experiments on temperate agricultural soils or identifying the mechanism for N retention. Methods Biochar derived from maize stover was applied to a maize cropping system in central New York State at rates of 0, 1, 3, 12, and 30 tha 1 in 2007. Secondary N fertilizer was added at 100, 90, 70, and 50 % of the recommended rate (108 kg N ha⁻¹). Nitrogen fertilizer enriched with ¹⁵N was applied in 2009 to the 0 and 12 tha⁻¹ of biochar at 100 and 50 % secondary N application. Results Maize yield and plant N uptake did not change with biochar additions (p>0.05; n=3). Less N (by 82 %; p