Agroecosystems and Land Resources of the Northern Great Plains

Abstract

The northern Great Plains have long been dominated by conventional tillage systems and cereal‐based rotations including summer fallow. Over the last decade, however, the use of conservation tillage systems has markedly increased and, through improved moisture storage, has provided an opportunity for more diversified extended rotations including oilseed, pulse, and forage crops throughout the region. Considerable research is being carried out to assess the adaptability of these new crops and to develop appropriate management strategies. Typically, this type of agronomic research is carried out at plot‐sized research sites, with the findings then being extrapolated to surrounding regions where growing conditions are thought to be reasonably similar. Because the environment itself largely dictates the success of a particular cropping system, extrapolation requires knowledge of the environmental conditions of the region and, in particular, the interaction of environmental components of soil and climate in relation to specific crop requirements. This paper describes 14 agroecoregions in the northern Great Plains and provides an initial framework for extrapolating agronomic information at broad regional scales. Because climate is the dominant crop production factor in the region, most of the agroecosystems represent broad climatic zones. Each agroecoregion is described in terms of its soil and landscape characteristics, with a particular focus being given to likely key environmental parameters related to the production of the new oilseed, pulse, and forage crops being introduced in the region.

Cover crop mixtures enhance stability but not productivity in a semi‐arid climate

“…Differences were more apparent at the West site (Fig. 2), which is typically the more arid of the two sites (Padbury et al, 2002). In 2016, dryland+irrigation treatments had consistently higher VWC values.…”

“…Since the East sites are close in proximity and thus similar environmentally, long term precipitation and temperature information is provided for Fargo. The long-term (1981-2010) mean annual precipitation is 498 mm and mean annual temperature is 4.4°C (Padbury et al, 2002). The dominant soil type is a Warsing loam (Fine-loamy, mixed, superactive, frigid, Oxyaquid Hapludoll) with 0 to 3% slope in Absaraka and Fargo Silty Clay (Fine, smectitic, frigid, Epiaquerts) with 0 to 3% slope in Fargo.…”

“…The dominant soil type is a Warsing loam (Fine-loamy, mixed, superactive, frigid, Oxyaquid Hapludoll) with 0 to 3% slope in Absaraka and Fargo Silty Clay (Fine, smectitic, frigid, Epiaquerts) with 0 to 3% slope in Fargo. This soil series is characterized by glacial till deposits located along the Red River with a level to gently sloping topography (Padbury et al, 2002). Soil test results indicated soil organic matter content of 27 and 83 g kg -1 in Absaraka and Fargo, respectively.…”

“…Additionally, soil macronutrients were evaluated at one site to assess N, P, and K relative differences among single species and multi-species cover crop plantings at the end of the growing season. (Padbury et al, 2002).…”

Integrating beef cattle on cropland affects net global warming potential

“…Though climatically distinct from the subtropical conditions of Brazil, the semiarid northern Great Plains of North America shares common attributes of extensive beef cattle production and abundant grazing resources (USDA 2017;Statistics Canada 2016). Nonirrigated cropland is common throughout the region, occupying over 51 Mha (Padbury et al 2002). Moreover, cropland is often juxtaposed to rangeland, providing agricultural producers the potential to utilize cropland for livestock when rangeland forage conditions are of poor nutritive value or in limited supply.…”