Productivity and environmental outcomes of integrated no‐till and maize residue harvest in the US Corn Belt

Abstract Along with sustained increases in maize ( Zea mays L.) yield in the US Corn Belt, the amount of residue left in the field has also increased and is expected to continue increasing into the future. While crop residues play a key role in protecting soils from erosion and maintaining soil organic carbon, high residue levels can hinder crop establishment and increase reliance on tillage. Using a meta‐analysis, we assessed the effects of maize residue harvest combined with no‐till on crop yield and nitrous oxide (N 2 O) emissions in continuous maize systems. In addition, a life‐cycle assessment was used to quantify greenhouse gas emissions associated with maize production. Compared with conventional tillage and residue retention, no‐till combined with residue harvest maintained maize yield, eliminating a yield penalty associated with no‐till alone, while reducing in‐field N 2 O emissions by 30% and total greenhouse gas emissions by 17%. Within no‐till systems, residue harvest increased maize yield by 6.4%, while reducing in‐field N 2 O emissions by 33% and total greenhouse gas emissions by 17%. These results are likely conservative as they represent historical data with lower residue production than present. Moreover, ongoing increases in residue production and spring precipitation in the US Corn Belt may exacerbate these responses in the future.