Large increases in maize residue carbon inputs in the US Corn Belt from 1980 to 2020

Data and R code for the figures in the article "Large increases in maize residue carbon inputs in the US Corn Belt from 1980 to 2020", Communications Earth & Environment.

Maize residue, the remaining biomass after crop harvest, represents the largest soil carbon input in agricultural lands. Residue affects crop yields and sustainability through its impact on soil carbon-nutrient-water processes. Here, we address the lack of spatial and temporal knowledge by synthesizing field experiments with public surveys to estimate maize residue quantity and quality at the county level in the US Corn Belt. We found that maize residue carbon input has increased by 46% from 1980 to 2020, with today’s gross production worth $14.3 billion in carbon markets. The increase was caused by increased maize productivity (77%) and area expansion (23%). While more residue production is desirable for soil carbon sequestration, large residue amounts challenge the implementation of conservation practices such as low-intensity tillage and cover crops. The historical increase in maize reisdue amount is large and variable across the landscape. Our study provides actionable data for re-assessing residue management practices to optimize productivity and sustainability, especially in high-yielding areas.