Effect of crop residue harvest on long-term crop yield, soil erosion and nutrient balance: trade-offs for a sustainable bioenergy feedstock

Abstract

Background: Agricultural residues could potentially be converted to bioenergy, but the sustainable harvest rate is unclear. Results: Residue removal increases soil loss at rates that vary with topography, crop rotation and management; decreases yields (100-year mean yields changed -0.07 to -0.08% for every percent of residue mass removed); decreases soil carbon (approximately 40–90 kg C ha^-1 year^-1 per Mg of residue harvested); and decreases soil nitrogen (∼3 kg N ha^-1 year^-1 per Mg residue harvested). Conclusion: Even where soil loss is within tolerable limits, harvesting residue is a question of trade-offs in terms of reduction of yield and loss of soil nutrients. The effects of increased residue harvest are highly variable, depending on local climate and soil erodibility and it is thus problematic to apply a single harvest rate globally. However, on flat land under conservation management, the majority of residue could be sustainably harvested for bioenergy.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Financial & competing interests disclosure

This work was funded in part with support from the US Department of Energy’s Great Lakes Bioenergy Research Center. Research was conducted at the Joint Global Change Research Institute, a joint collaboration between the Pacific Northwest National Laboratory and the University of Maryland, managed by Battelle. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.