Straw

“Across 24 Oregon tall fescue seed fields (stands 2-20 years), total SOC stocks were unchanged by stand age or straw management, but older stands stored more total field-level carbon from greater root inputs and straw retention boosted the labile (particulate) carbon fraction in topsoil along with microbial biomass and respiration. These grass seed fields held less topsoil carbon than nearby natural grasslands but more than arable crop fields, so keeping stands longer and retaining straw supports soil biology even without measurable SOC gains.”

“County-level life cycle modeling shows Illinois maize has a carbon intensity 9%-12% below the US average of 251 g CO2e/kg, and maize grown within 56 km of ethanol plants is 14%-17% lower, driven by high yields and efficient fertilizer use. National average CI values understate the climate performance of high-yielding regions, and cover crops and conservation tillage shift scores differently from county to county.”