Location: Soil Management and Sugarbeet ResearchTitle: Long-term nitrogen balance of an irrigated no-till soil-corn system
|D Adamo, Robert|
|Del Grosso, Stephen - Steve|
Submitted to: Nutrient Cycling in Agroecosystems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2023
Publication Date: 6/14/2023
Citation: Delgado, J.A., Halvorson, A.D., D'Adamo, R.E., Stewart, C.E., Floyd, B.A., Del Grosso, S.J. 2023. Long-term nitrogen balance of an irrigated no-till soil-corn system. Nutrient Cycling in Agroecosystems. 126:229-243. https://doi.org/10.1007/s10705-023-10287-9.
Interpretive Summary: Efficient use of nitrogen is essential to the sustainability of cropping production. USDA researchers in Fort Collins, CO carried out a long-term study to quantify the fate of nitrogen in irrigated corn production under no-till management, a key conservation practice. Looking deep into the soil, they found that irrigated no-till continuous corn system is losing nitrogen from the soil organic matter, consistent with results that point to the loss of carbon from deeper in the soil. Their work highlights the importance of long-term evaluation of agricultural systems, as these trends can be overlooked in short studies, as well as potential to better conserve nitrogen in no-till with alternative management practices.
Technical Abstract: Nitrogen (N) is the most important element in agricultural production worldwide, but it is a highly mobile element that escapes to the environment via atmospheric, surface, and leaching loss pathways. We conducted a long-term study in an irrigated no-till continuous corn system from fall 2005 to fall 2018 at the Halvorson research plots near Fort Collins, Colorado. The total N fertilizer applications (TNFAs) of 0, 874, 1,714, 2,554, and 3,201 kg N ha-1 for the 2006 to 2018 growing seasons were equivalent to 0, 67, 132, 197, and 246 kg N ha-1 y-1 on an annual basis, respectively. The N use efficiency (NUE) of the harvested grain (NUEHG) was 49.2, 46.3, 35.1, and 29.4% for the N fertilizer applications (NFAs) of 0, 67, 132, 197, and 246 kg N ha-1 y-1, respectively. The NUE of the system (NUESys), including changes in soil organic N (SON) and inorganic N from the 0 to 120 cm depths, was 90.0, 72.5, 58.6, 49.2 and 41.4% for the TNFAs of 0, 67, 132, 197, and 246 kg N ha-1 y-1, respectively. The N lost from N-fertilized plots ranged from 27.5% with the 67 kg N ha-1y-1 rate to 58.6% for the 246 kg N ha-1 y-1 rate, with an average loss across treatments of 15 kg N ha-1y-1 of SON in the top 30 cm of soil. There is still a need to develop best management practices that reduce N losses from no-till and agricultural systems.