Reductions in soil water nitrate beneath a perennial grain crop compared to an annual crop rotation on sandy soil

Nitrate ( NO3- -N) leaching into groundwater as a result of high nitrogen (N) fertilizer rates to annual crops presents human health risks and costs associated with water treatment. Leaching is particularly serious concern on sandy soils overlying porous bedrock. Intermediate wheatgrass (IWG) [ Thinopyrum intermedium (Host.) Barkw. & D.R. Dewey], perennial grass that being bred produce agronomically economically viable grain, which commercially available Kernza ® . low-input crop has the potential profitable grain biomass yields while reducing id="M2">NO3- -N compared common row rotations in Upper Midwest. We yields, soil solution id="M3">NO3- concentration, extractable id="M4">NO3- -N, content, root under IWG conventionally managed corn Zea mays L.) soybean Glycine max (L.) Merr.] rotation for 3 years Verndale loam Central Minnesota. Mean id="M5">NO3- was 77–96% lower than rotation. Soil content greater annuals early growing season, suggesting use by during this time. Interactions between treatments depth were observed Year 3. Root from 0 60 cm below surface five times beneath soybean, may explain differences id="M6">NO3- among crops. With irrigation coarse structured soils, 854, 434, 222 kg ha ?1 Years 1–3 vegetative averaged 4.65 Mg yr ; comparable other reports heavier region. Annual consistent local averages. These results confirm effectively reduces id="M7">NO3- concentrations even supporting its broader adoption land vulnerable id="M8">NO3- leaching.