Groundwater and agriculture: Insights from farmers in central Minnesota on how to protect both

Excerpt

In agricultural areas with groundwater that is highly sensitive to pollution and surface water resources that are sensitive to groundwater withdrawal, farmers are under pressure from government agencies and environmental groups to improve their on-farm management practices (Kennedy 2015a, 2015b; Marcotty 2012). One area where conflicts over groundwater and agriculture are growing is the central sands region of Minnesota, United States (Gunderson 2014; Haugen 2014; Marcotty 2013; Robertson 2009; Vogel 2014b). This area is characterized by coarse-textured soils formed from glacial outwash (USDA NRCS 2018), a water table that is vulnerable to pollution (Adams 2016), and extensive agricultural production with crops such as corn (Zea mays L.), soybean (Glycine max [L.] Merr.), alfalfa (Medicago sativa L.), wheat (Triticum aestivum L.), oats (Avena sativa L.), potato (Solanum tuberosum L.), and dry edible beans (Phaseolus vulgaris L.) (USDA NASS 2014, 2017).

While the trend of change in nitrate (NO₃) concentrations over time in this region is either stable (Minnesota Pollution Control Agency et al. 2018) or slightly increasing (MDA 2015b), the extent of NO₃ contamination in groundwater is already widespread (MN EQB 2017). Nitrate concentrations in groundwater are found at elevated levels in this region for public water systems (PWS) (MDH 2018)…