Science‐based maize stover removal can be sustainable

Maize (Zea mays L.) stover can be harvested for multiple uses or left in the field to sustain soil organic carbon (SOC), cycle essential plant nutrients, and protect soil health. This 13-yr field study quantified effects of no (0 Mg ha–1 yr–1), low (1.0–1.4 Mg ha–1 yr–1), moderate (3.5–4.0 Mg ha–1 yr–1), or high rates (4.7–5.4 Mg ha–1 yr–1) of stover harvest from either continuous maize or maize–soybean [Glycine max (L.) Merr. ] rotation on grain yield, plant nutrient concentrations, and multiple soil properties at two sites in Iowa. Stover harvest increased plant macroand micro-nutrient removal, but did not affect average grain yields of either crops. Soil inorganic carbon (IC), SOC, bulk density, pH, and cation exchange capacity (CEC) showed no significant differences due to stover harvest. Plant tissue and soil-test nutrient concentration effects were also minor and site-specific. Stover harvest significantly (p < .05) decreased exchangeable K and Ca concentrations by 8.3–23.8% and 0.3–22.5% but overall soil health indicator effects were minimal. Overall, based on crop yields, plant nutrient and soil-test concentrations, soil health indicators, and carbon sequestration estimates, maize stover harvest can be sustainable provided: (a) grain yields consistently exceed 11 Mg ha–1, (b) stover removal does not exceed 40% of the aboveground biomass (i.e., 3.5–4.0 Mg ha–1 yr–1), and (c) plant nutrients (especially K) are closely monitored. Disciplines Agriculture | Agronomy and Crop Sciences | Soil Science Comments This article is published as Nunes, Marcio R. , Mriganka De, Marshall McDaniel, John Kovar, Stuart Birrell, and Douglas L. Karlen. "Science‐based maize stover removal can be sustainable. " Agronomy Journal (2021). doi:10.1002/agj2.20724. Authors Marcio R. Nunes, Mriganka De, Marshall D. McDaniel, John L. Kovar, Stuart Birrell, and Douglas L. Karlen This article is available at Iowa State University Digital Repository: https://lib.dr.iastate.edu/agron_pubs/719 Received: 3 November 2020 Accepted: 9 May 2021 DOI: 10.1002/agj2.20724 A R T I C L E A g r o n o m y , S o i l s , a n d E n v i r o n m e n t a l Q u a l i t y Science-based maize stover removal can be sustainable Marcio R. Nunes1 Mriganka De2 Marshall D. McDaniel3 John L. Kovar1 Stuart Birrell4 Douglas L. Karlen5 1 National Laboratory for Agriculture and the Environment, USDA-Agricultural Research Service (ARS), Ames, IA 50011, USA 2 Dep. of Biological Sciences, Minnesota State Univ. – Mankato, Mankato, MN 56001, USA 3 Dep. of Agronomy, Iowa State University (ISU), Agronomy Hall, Ames, IA 50011, USA 4 Dep. of Agricultural and Biosystems Engineering, Iowa State Univ. (ISU), Ames, IA 50011, USA 5 USDA-ARS (retired), Current address: DLKarlen Consulting LLC, St. Paul, MN 55102, USA Correspondence Márcio R. Nunes, National Laboratory for Agriculture and the Environment, USDAAgricultural Research Service (ARS), 1015 N. University Blvd., Ames, IA, 50011, USA. Email: marcio_r_nunes@alumni.usp. br Assigned to Associate Editor Kabindra Adhikari. Abstract Maize (Zea mays L.) stover can be harvested for multiple uses or left in the field to sustain soil organic carbon (SOC), cycle essential plant nutrients, and protect soil health. This 13-yr field study quantified effects of no (0 Mg ha yr), low (1.0–1.4 Mg ha yr), moderate (3.5–4.0 Mg ha yr), or high rates (4.7– 5.4 Mg ha yr) of stover harvest from either continuous maize or maize–soybean [Glycine max (L.) Merr. ] rotation on grain yield, plant nutrient concentrations, and multiple soil properties at two sites in Iowa. Stover harvest increased plant macroand micro-nutrient removal, but did not affect average grain yields of either crops. Soil inorganic carbon (IC), SOC, bulk density, pH, and cation exchange capacity (CEC) showed no significant differences due to stover harvest. Plant tissue and soil-test nutrient concentration effects were also minor and site-specific. Stover harvest significantly (p < .05) decreased exchangeable K and Ca concentrations by 8.3–23.8% and 0.3–22.5% but overall soil health indicator effects were minimal. Overall, based on crop yields, plant nutrient and soil-test concentrations, soil health indicators, and carbon sequestration estimates, maize stover harvest can be sustainable provided: (a) grain yields consistently exceed 11 Mg ha, (b) stover removal does not exceed 40% of the aboveground biomass (i.e., 3.5–4.0 Mg ha yr), and (c) plant nutrients (especially K) are closely monitored.