Location: Northwest Irrigation and Soils ResearchTitle: Growing and non-growing season nitrous oxide emissions from irrigated crops utilizing dairy manure
Submitted to: Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2021
Publication Date: N/A
Technical Abstract: Information is limited on greenhouse gas (GHG) emissions from irrigated cropping systems utilizing dairy manure, especially during the non-growing season. In semiarid southern Idaho, we measured nitrous oxide (N2O) emissions at three different field sites where manure was used as fertilizer in dairy forage rotations. Daily N2O flux measurements were conducted using vented, non-steady-state, closed chambers. The chambers were manually deployed a few times a week, while another set of chambers were fully automated, allowing for continuous flux measurements. Nitrous oxide pulses during the growing season were highest after the first few irrigation events and greatest from the manure treatments versus synthetic fertilizer. During the non-growing season, in winter and early spring, freeze-thaw events dramatically increased N2O fluxes and strong diurnal pulses were noted. Cumulative N2O emissions during the non-growing season were found to be approximately equal to those during the growing season. Cumulative annual losses of N2O were positively correlated with the manure application rate. Despite the high N2O emissions from the manure treatments, this only represents about one percent or less of the total applied nitrogen.