Location: Agroecosystems Management ResearchTitle: Science-based maize stover removal can be sustainable
|NUNES, MARCIO - Orise Fellow|
|DE, MRIGANKA - Minnesota State University|
|MCDANIEL, MARSHALL - Iowa State University|
|BIRRELL, STUART - Iowa State University|
|KARLEN, DOUGLAS - Retired ARS Employee|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2021
Publication Date: 5/16/2021
Citation: Nunes, M.R., De, M., Mcdaniel, M.D., Kovar, J.L., Birrell, S.J., Karlen, D.L. 2021. Science-based maize stover removal can be sustainable. Agronomy Journal. https://doi.org/10.1002/agj2.20724.
Interpretive Summary: Maize (corn) stover has many potential uses including: (i) protection of the soil surface from water and wind erosion, (ii) supplying carbon to the soil organic matter pool, (iii) cycling plant nutrients, or (iv) being used as a feedstock for bioenergy or other bio-products. The 13-year average maize grain yield was 10.2 and 11.6 Mg ha-1 (163 and 184 bu ac-1) and 3.78 and 3.22 Mg ha-1 (56 and 48 bu ac-1) for soybean at the Bruner and Boyd sites. Stover harvest averaged 0, 1.0, 3.5, and 4.7 or 0, 1.4, 4.0, and 5.4 Mg ha-1 (0, 0.5, 1.5, and 2.1 or 0, 0.6, 1.8, and 2.4 tons ac-1) at the two sites, respectively. Stover harvest increased carbon, nitrogen, phosphorus, and potassium (K) removal by an average of 450, 6, 0.5, and 7 kg Mg-1 (900, 13, 1, and 15 lb ton-1), respectively. Excessive stover harvest, full-width tillage, and lack of winter soil surface cover accelerated soil erosion. This information will help producers determine if and how much stover they should harvest, and various industries determine if they should invest in products using stover as a primary feedstock.
Technical Abstract: Maize (Zea mays L.) stover can be harvested for multiple uses, but there are sustainability concerns due to mass export of carbon and nutrients which may degrade soil health. We measured the 13-year effects of harvesting none (0 Mg ha-1 y-1), low (1.0 to 1.4 Mg ha-1 y-1), moderate (3.5 to 4.0 Mg ha-1 y-1), or high rates (4.7 to 5.4 Mg ha-1 y-1) of stover from continuous maize and a maize – soybean [Glycine max. (L.) Merr.] rotation on grain yield, plant nutrients, and multiple soil properties at two sites in Iowa, USA. Stover harvest increased plant macro- and micro-nutrient removal, but average maize and soybean grain yields were not affected. There were also no significant effects on soil organic or inorganic carbon, bulk density, soil pH, or cation exchange capacity. There were minor effects on crop tissue nutrient and soil plant-available nutrient concentrations, but they were generally site-specific. Stover harvest decreased exchangeable K and Ca concentration after 13 years (p<0.05), but overall effects on soil health indicators were minimal.