Cover crops to improve soil health in the North American Great Plains

Abstract

Rotating cereal crops [e.g., wheat (Triticum aestivum L.) with a 10-to 21-month summer fallow period (fallow) is a common farming practice in dryland (rainfed) agricultural This article is protected by copyright. All rights reserved. 2 regions. Fallow is associated with several challenges including low precipitation storage efficiency, depletion of soil organic carbon (SOC), loss of soil fertility, little crop residue retention and soil erosion, and few control options for herbicide resistant (HR) weeds. The inability to effectively control HR weeds poses a major challenge to maintaining soil and water conservation practices such as no-till, as some producers are considering tillage to control weeds. Cover crop (CC) integration into wheat-based production systems to replace portions of the fallow period provides an opportunity to increase SOC, improve soil fertility, suppress weeds, and increase profitability of dryland crop production, especially when CCs are used as forage. This forum paper used the North American Great Plains as a model region to review information on (1) challenges of dryland agriculture; (2) integrating CCs in dryland agriculture; (3) benefits, challenges, and limitations of CCs in dryland crop production; (4) management options for CC integration in dryland grain systems; and (5) recommendations for future research efforts. Abbreviations: CC, cover crop; HR, herbicide resistance; NT, no-tillage; SOC, soil organic carbon.

Near‐term problems in meeting world food demands at regional levels: A special issue overview

“…Obour et al. (2021) examine the role cover crops can play to improve soil health in the dryland region of the U.S. Great Plains. The Great Plains is a major grain‐producing region accounting for most of the wheat (62%) and sorghum (96%) produced in the United States (USDA‐NASS, 2019).…”

“…Obour et al. (2021) discuss the potential of integrating cover crops to replace fallow as a solution to the above problems while also increasing soil organic matter, improving soil fertility by scavenging nutrients, and providing livestock fodder.…”

“…They suggest the solution will be recognizing the connections between soil health and food security and that both be addressed simultaneously. Obour et al (2021) examine the role cover crops can play to improve soil health in the dryland region of the U.S. Great Plains. The Great Plains is a major grain-producing region accounting for most of the wheat (62%) and sorghum (96%) produced in the United States (USDA-NASS, 2019).…”

“…While the adoption of no-till practices has had a positive impact on soil and water conservation practices, the challenges relating to controlling herbicide resistant weeds, and soil compaction poses a threat to the long-term sustainability of the no-till practices in the region. Obour et al (2021) discuss the potential of integrating cover crops to replace fallow as a solution to the above problems while also increasing soil organic matter, improving soil fertility by scavenging nutrients, and providing livestock fodder.…”

Cool-season cover crop effects on forage productivity and short-term soil health in a semi-arid environment

“…For example, several soil conservation approaches have been undertaken, such as the no-till system, biodiversity inclusion, reduced tillage, and cover cropping to help restore soil health and sustainability of dryland agroecosystems (Blanco-Canqui et al ., 2013; Nielsen et al ., 2016). In more recent times, cover cropping has been the subject of widespread scientific studies across varying agroecosystems at both temporal and spatial scales to elucidate their benefits compared to the traditional fallow systems (e.g., Nair and Ngouajio, 2012; Reese et al ., 2014; Liebig et al ., 2015; Amsili and Kaye, 2020; Obour et al ., 2021; Thapa et al ., 2021).…”