Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/26/2024
Publication Date: 9/25/2024
Citation: Johnson, J.M., Helseth, C.M., Weyers, S.L., Papanicolaou, A.N., Busche, D. 2024. The LTAR cropland common experiment at Upper Mississippi River Basin-Morris. Journal of Environmental Quality. 1-10. https://doi.org/10.1002/jeq2.20631.
DOI: https://doi.org/10.1002/jeq2.20631

Interpretive Summary: The Long-Term Agroecosystem Research (LTAR) network is a group of researchers across the nation. The network’s goal is finding solutions to advance agricultural productivity, protect environmental quality, promote peoples’ well-being, and respond to a changing climate. Four locations, Ames, IA; Morris, MN; Platteville, WI; and St. Paul, MN, represent the Upper Mississippi River Basin (UMRB) research team. The UMRB contributes to the LTAR-common cropland experiment (CCE), which compares locally prevailing practices to alternative practices. The Morris, MN, site (LTAR-UMRB-Morris), the most northern of these four locations, has colder, drier winters and the shortest growing season. For the UMRB-Morris location, the prevailing practice is a corn/soybean rotation with annual deep ripping tillage (PREV); and the two alternative practices are (1) a shallow-strip till in a corn/soybean rotation (ALT1) and (2) a shallow strip tillage or without tillage in a corn, soybean and wheat rotation with a winter oilseed or other winter cover following wheat. Two local farmers provide access to their fields for monitoring crop growth, water use and carbon dioxide exchange with advanced technologies/equipment. Soil samples are also collected to understand how the practices might alter soil properties. Similar practices are studied at the plot scale on the Swan Lake Research Plan. The information collected is useful to producers interested in potential benefits of prevailing and alternative practices to meet many demands on American producers.

Technical Abstract: The Upper Mississippi River Basin (UMRB) Long-Term Agroecosystem Research (LTAR) watershed is hydrologically complex, with a notable temperature and precipitation gradient across four locations of Ames, IA; Platteville, WI; Morris, MN; and St. Paul, MN. Each location established LTAR – Common Cropland Experiment (CCE) scenarios to fit local climatic and cultural practices. The UMRB-Morris location, the most northern of the sites, contributes to the major watersheds of the UMRB and the Red River of the North. Both on-farm and plot-scale studies are included. The prevailing (PREV) system is a corn (Zea maize, L.)/soybean (Glycine max, L.) rotation with annual deep ripping tillage. Two Alternative systems are 1) ALT1- shallow-strip till in a corn/soybean rotation and 2) ALT2 – shallow tillage/rotational no-tillage in a corn/soybean/wheat (Triticum aestivum, L.) + winter oilseed and cover crops. On-farm fields are equipped with eddy covariance towers and include 16 geo-referenced soil core sampling sites for incremental samplings. Each field is sampled annually for crop yield and management data are collected. Plot-scale versions of the treatments are managed at the Swan Lake Research Farm. On-farm and plot-scale fields are instrumented with a Phenocam to capture continuous photographic records. The CCE at Morris aims to integrate soil, crop, weather data (captured by stationary and mobile sensors), and image classification to assess the benefits of different management strategies.