Leaching losses of dissolved organic carbon and nitrogen from agricultural soils in the upper US Midwest

Mir Zaman Hussain; G Philip Robertson; Bruno Basso; Stephen K Hamilton

doi:10.1016/j.scitotenv.2020.139379

Leaching losses of dissolved organic carbon and nitrogen from agricultural soils in the upper US Midwest

Sci Total Environ. 2020 Sep 10:734:139379. doi: 10.1016/j.scitotenv.2020.139379. Epub 2020 May 14.

Authors

Mir Zaman Hussain¹, G Philip Robertson², Bruno Basso³, Stephen K Hamilton⁴

Affiliations

¹ W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060, USA; Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA.
² W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060, USA; Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA; Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA.
³ W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060, USA; Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA; Department of Earth and Environmental Sciences, Michigan State University, East Lansing, MI 48824, USA.
⁴ W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060, USA; Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA; Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA; Cary Institute of Ecosystem Studies, Millbrook, NY 12545, USA. Electronic address: [email protected].

PMID: 32473451
DOI: 10.1016/j.scitotenv.2020.139379

Abstract

Leaching losses of dissolved organic carbon (DOC) and nitrogen (DON) from agricultural systems are important to water quality and carbon and nutrient balances but are rarely reported; the few available studies suggest linkages to litter production (DOC) and nitrogen fertilization (DON). In this study we examine the leaching of DOC, DON, NO₃^-, and NH₄⁺ from no-till corn (maize) and perennial bioenergy crops (switchgrass, miscanthus, native grasses, restored prairie, and poplar) grown between 2009 and 2016 in a replicated field experiment in the upper Midwest U.S. Leaching was estimated from concentrations in soil water and modeled drainage (percolation) rates. DOC leaching rates (kg ha^-1 yr^-1) and volume-weighted mean concentrations (mg L^-1) among cropping systems averaged 15.4 and 4.6, respectively; N fertilization had no effect and poplar lost the most DOC (21.8 and 6.9, respectively). DON leaching rates (kg ha^-1 yr^-1) and volume-weighted mean concentrations (mg L^-1) under corn (the most heavily N-fertilized crop) averaged 4.5 and 1.0, respectively, which was higher than perennial grasses (mean: 1.5 and 0.5, respectively) and poplar (1.6 and 0.5, respectively). NO₃^- comprised the majority of total N leaching in all systems (59-92%). Average NO₃^- leaching (kg N ha^-1 yr^-1) under corn (35.3) was higher than perennial grasses (5.9) and poplar (7.2). NH₄⁺ concentrations in soil water from all cropping systems were relatively low (<0.07 mg N L^-1). Perennial crops leached more NO₃^- in the first few years after planting, and markedly less after. Among the fertilized crops, the leached N represented 14-38% of the added N over the study period; poplar lost the greatest proportion (38%) and corn was intermediate (23%). Requiring only one third or less of the N fertilization compared to corn, perennial bioenergy crops can substantially reduce N leaching and consequent movement into aquifers and surface waters.

Keywords: Biofuel; Corn; Dissolved organic matter; Grass; Nitrate; Poplar.