Greenhouse gas emissions from tillage practices and crop phases in a sugarbeet‐based crop rotation

Abstract Information is needed on greenhouse gas (GHG) emissions due to tillage and crop type on sugarbeet ( Beta vulgaris L.)‐based crop rotations. We measured CO 2 , N 2 O, and CH 4 emissions as affected by tillage (conventional till [CT], no‐till [NT], and strip till [ST]) under sugarbeet and spring wheat ( Triticum aestivum L.) phases of an irrigated sugarbeet–pea ( Pisum sativum L.)–spring wheat rotation from 2018 to 2021 in the US northern Great Plains. Greenhouse gases were measured using a static chamber at 3‐ to 28‐day intervals, depending on plant growth and environmental conditions, throughout the year. The CO 2 and N 2 O fluxes peaked for 2–8 months immediately after tillage, planting, fertilization, intense precipitation, and irrigation. The CH 4 flux varied little, except for some peaks in the first year. Cumulative annual CO 2 flux was 19%–30% greater for CT than NT in 2019–2020 and 2020–2021, and 13% greater for CT than ST in 2020–2021. Cumulative N 2 O flux was 31%–36% greater for CT than ST in 2018–2019 and 2020–2021, but 33%–83% lower for sugarbeet than spring wheat in all years. Cumulative CH 4 flux was 83% lower for CT than NT and 68% lower for sugarbeet than spring wheat in 2018–2019. The GHG balance was 15%–23% greater for CT than NT and ST in 2019–2020 and 2020–2021 and 31% greater under sugarbeet than spring wheat in 2018–2019. No‐tillage can reduce GHG emissions compared to conventional tillage, and sugarbeet can reduce N 2 O emissions compared to spring wheat in sugarbeet‐based crop rotations.