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Potential Nitrogen Losses in Relation to Spatially Distinct Soil Management History and Biochar Addition
Author(s) -
Baechle Ben,
Davis Adam S.,
Pittelkow Cameron M.
Publication year - 2018
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2017.06.0246
Subject(s) - biochar , loam , tillage , agronomy , cycling , environmental science , chemistry , environmental chemistry , nitrogen , soil carbon , leachate , soil water , soil management , soil science , pyrolysis , biology , history , organic chemistry , archaeology
Soil functional zone management strategies including ridge tillage have been shown to increase in‐row (IR) compared with between‐row (BR) soil nitrogen (N) availability due to the development of contrasting soil properties and carbon (C) and N cycling processes. However, potential N losses may also increase for IR positions, representing an environmental tradeoff. Although biochar has putative contributions to tightening N cycles, its effect within spatially distinct management zones has not been quantified. This study evaluated the potential for biochar to reduce soil nitrous oxide (N 2 O) emissions and leachate nitrate (NO 3 − ) concentrations as influenced by changes in soil properties after 5 yr of ridge tillage in a silty clay loam soil. Soil columns for IR and BR positions were treated with and without biochar at 10 Mg ha −1 in a 100‐d laboratory incubation ( n = 4 replications). Results indicate that biochar increased average daily N 2 O emissions in IR by 30% but decreased them by 39% in BR. In both positions, biochar decreased NO 3 − concentrations in soil solution and leachate by 11 to 20% and 10 to 15%, respectively. Our findings suggest that long‐term changes in soil C and N cycling processes may increase the potential for N 2 O emissions in IR compared with BR positions. Although most biochar studies have not accounted for within‐field soil variability, our results indicate that biochar may differentially affect soil N 2 O emissions depending on spatially distinct soil management history. Findings from this laboratory study stress the need for field research evaluating spatial differences in biochar N 2 O mitigation potential. Core Ideas Ridge tillage and biochar effects on potential N losses assessed in soil column study. N 2 O emissions increased for in‐row vs. between‐row positions, but not N leaching losses. Biochar consistently decreased NO 3 − concentrations in soil solution and leachate. Biochar decreased between‐row N 2 O emissions but increased in‐row emissions. Field studies evaluating spatial variability of biochar N 2 O mitigation potential are needed.