Cropping pattern changes diminish agroecosystem services in North and South Dakota, USA

Authors: O'Brien, Peter; Hatfield, Jerry; DOLD, CHRISTIAN - Orise Fellow; Kistner-Thomas, Erica; WACHA, KENNETH - Orise Fellow

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/17/2019
Publication Date: 2/26/2020
Publication URL: https://handle.nal.usda.gov/10113/6937387
Citation: O'Brien, P.L., Hatfield, J.L., Dold, C., Kistner-Thomas, E.J., Wacha, K.M. 2020. Cropping pattern changes diminish agroecosystem services in North and South Dakota, USA. Agronomy Journal. 112(1):1-24. https://doi.org/10.1002/agj2.20001.
DOI: https://doi.org/10.1002/agj2.20001

Interpretive Summary: The landscapes in North and South Dakota have been changing over the past several decades. More land is being converted from perennial vegetation into row crop agricultural production, known as agricultural expansion, and fewer different types of crops are being grown, known as crop rotation simplification. These two changes have been linked to many different causes, including agronomic, economic, and sociopolitical factors, but researchers have not comprehensively described the consequences of these changes. The objective of this research was to identify how much agricultural expansion and crop rotation simplification has been occurring, why it has been happening, and most importantly, what are the consequences. Overall, these two land use changes have led to more corn and soybean production, but they may also be associated with risks to long-term stability of agriculture in the region. Too much focus on increasing crop production has created landscapes that have altered water flow patterns, lowered resistance to weed and insect invasions, and reduced capacity for storing carbon. These consequences indicate that agricultural systems in North and South Dakota may not be able to withstand external pressures like drought, insect invasion, or even changes in economic markets. To reduce the risk of extreme damage from external pressures, land managers should consider all parts of the agricultural ecosystem, including water balances, nutrient balances, and ecosystem stability, rather than simply crop production.

Technical Abstract: North Dakota and South Dakota are important agricultural production states, contain almost half the area of the US national grasslands, and include much of the Prairie Pothole Region, an area of global importance for biodiversity. In the past several decades, land use patterns have changed due to increased agricultural expansion and crop rotation simplification, namely an increase in corn-soybean systems. This research investigates the nature and extent of those land use changes, the underlying causes driving the changes, and the consequences they have on agroecosystem services. The framework of ecosystem services is underutilized in agricultural research, but it can be used to describe the sustainability, resistance, and resilience of the system in relation to these land use changes. The current trends are focused on maximizing provisioning services (i.e., food, fuel) at the expense of regulating, cultural, and supporting services. The decline of regulating services can be seen in river flow and water quality trends throughout the region, as well as increased management (i.e., pesticides, herbicides) resulting from diminished bioregulation of pests and weeds. The impacts on supporting services are demonstrated by altered C balances and water cycling, while the loss of cultural connection to the land is evidenced by a decrease in land conservation. Overall, these changes are making the land in North and South Dakota more susceptible to stressors, such as drought, crop pests, or even economic trends, which could greatly harm these agroecosystems and have nationwide ramifications.