Growing and non-growing season nitrous oxide emissions from manured soil under irrigation

Dungan, R.S. and Leytem, A.B. and Bjorneberg, D.L. (2023) Growing and non-growing season nitrous oxide emissions from manured soil under irrigation. Agriculture, Ecosystems and Environment. 348:108413. 1 June 2023.

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Abstract

Dairy manure is used in semiarid southern Idaho to improve soil fertility, but campaigns to measure resulting nitrous oxide (N2O) emissions over the complete year have not been conducted to date. The objective of this study was to measure N2O fluxes throughout the growing and non-growing seasons in 2020 (sugar beet) and 2021 (corn silage) in a field that received inorganic N fertilizer or was previously treated with dairy manure solids on an annual and biennial basis for 8 years. Gas fluxes were measured daily using automated chambers that were connected to a gas chromatograph for in situ analysis of N2O. The N2O emissions were found to be highly episodic and major pulses were associated with freeze-thaw events in the winter, irrigation events during the growing season, and soil disturbance at harvest. Emissions were greatest from soil that had received manure at the highest annual application rate of 52 Mg/ha (dry wt.), with cumulative totals of 3.6 and 3.0 kg N2O-N/ha in 2020 and 2021, respectively. These cumulative totals were about 3-fold greater than emissions from plots treated with inorganic fertilizer or manure at 17 Mg/ha annually or 35 Mg/ha biennially. This outcome can be attributed to high concentrations of nitrate produced through mineralization of organic N in manure. Emission factors indicated that 0.6 to 0.9% of the total N applied was lost as N2O-N over the two years. When breaking down the emissions by season, anywhere from 49 to 63% (2020) and 37 to 58% (2021) of the N2O-N emissions occurred during the non-growing season. Cumulative growing and non-growing season N2O emissions were found to be statistically equivalent in the inorganic fertilizer and manure treatments. This finding stresses the need to also measure N2O emissions during the non-growing season as a way to improve the accuracy of annual emission estimates.

Item Type:	Article
NWISRL Publication Number:	1758
Subjects:	Irrigation > Sprinkler irrigation > Infiltration Manure > Composted manure Manure
Depositing User:	Users 11 not found.
Date Deposited:	22 Jun 2023 19:55
Last Modified:	22 Jun 2023 19:55
Item ID:	1798
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/1798