Crop residue management challenges: A special issue overview

Authors: CLAY, DAVID - SOUTH DAKOTA STATE UNIVERSITY; ALVERSON, RONALD - FARMER; Johnson, Jane; KARLEN, DOUGLAS; CLAY, SHARON - SOUTH DAKOTA STATE UNIVERSITY; WANG, MICHAEL - ARGONNE NATIONAL LABORATORY; BRUGGEMAN, STEPHANIE - SOUTH DAKOTA STATE UNIVERSITY; WESTHOFF, SHAINA - SOUTH DAKOTA STATE UNIVERSITY

Submitted to: Agronomy Journal
Publication Type: Literature Review
Publication Acceptance Date: 10/18/2018
Publication Date: 1/1/2019
Publication URL: https://handle.nal.usda.gov/10113/6471063
Citation: Clay, D.E., Alverson, R., Johnson, J.M., Karlen, D.L., Clay, S., Wang, M.Q., Bruggeman, S., Westhoff, S. 2019. Crop residue management challenges: A special issue overview. Agronomy Journal. 111:1-3. https://doi.org/10.2134/agronj2018.10.0657.
DOI: https://doi.org/10.2134/agronj2018.10.0657

Interpretive Summary: Managing crop residues is an issue for farmers worldwide as they strive to balance economic and environmental goals. The amount of residue a crop produces varies among crop species and cultivar, weather, soil and other management choices. Too much residue on the soil surface can cause problems for planting resulting in few plants growing. In areas with cold, wet springs too much residue can slow down soil drying and warming delaying planting. In contrast, not enough residue also is problematic. Soil without enough residue cover is exposed to wind and water, which can result in soil erosion. Since it takes continual input of plant matter to replace normal turnover of soil organic matter, excess removal of residue will cause a loss of soil organic matter. Repeated removal of residue can lead to a loss in soil productivity, which means more fertilizer might be needed causing increases in costs for growing the crop. This work reports outcome from the "Crop Residues for Advanced Biofuels: Effects on Soil Carbon" workshop held in Sacramento, CA, in 2017. The special journal issue summarizes knowledge gaps associated with crop residue management and expands the discussion from a regional Midwestern U.S. to a global perspective. Core ideas are that (1) farmers face challenges balancing economic and environmental goals; (2) economic and environmental goals are challenge in the United States and around the world; (3) research data can validate simulation models and (4) crop residue harvest impacts soil health, crop productivity, and greenhouse gas emissions. This work is important for crop producers, ethanol producers, ethanol regulators, modelers, scientists and policymakers.

Technical Abstract: Crop residue management is a worldwide challenge for farmers striving to balance economic and environmental goals within agricultural systems. It is challenging because the amount of residue produced is highly variable due to soil, climate, crop and genetic factors. Furthermore, excessive or insufficient amounts of crop residue can be detrimental with the former impairing soil-seed contact, immobilizing N, and/or keeping soils cool and wet, while the latter can result in loss of soil organic matter (SOM), increased soil erosion, and a gradual loss of productivity. This special issue evolved as an outcome of “Crop Residues for Advanced Biofuels: Effects on Soil Carbon” workshop held in Sacramento, CA, in 2017. The goal is to provide a forum for identifying knowledge gaps associated with crop residue management and to expand the discussion from a regional Midwestern U.S. to a global perspective. Several crop residue experiments as well as simulation modeling studies are included to examine effects of tillage, crop rotation, livestock grazing, and cover crops on greenhouse gas (GHG) emissions, crop yield, and soil or plant health. Core concepts that emerged include: (1) farmer challenges associated with maintaining economic and environmental sustainability; (2) the global commonality of challenges whether in the U.S. Midwest or elsewhere in the world; and (3) the use of carbon flux tower data to validate simulation models and (4) quantify the impact of crop residue harvest on soil health, productivity, and GHG emissions.