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Greenhouse gas emissions from an irrigated cropping rotation with dairy manure utilization in a semiarid climate

Dungan, R.S. and Leytem, A.B. and Tarkalson, D.D. (2021) Greenhouse gas emissions from an irrigated cropping rotation with dairy manure utilization in a semiarid climate. Agronomy Journal. 113(2):1222-1237. 3 March 2021.

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Greenhouse gas (GHG) emissions data from irrigated cropping systems utilizing dairy manure are needed in semiarid western regions. The objectives of this field study were to (i) determine the effect of synthetic N fertilizer (urea), enhanced-efficiency synthetic fertilizer (SuperU), composted dairy manure, dairy manure applications (fall and spring applied), and a control (no fertilizer or manure) on GHG losses over the growing season and overall global warming potential (GWP) and (ii) evaluate the influence of irrigation and field/crop management practices on GHG fluxes. The treatments were not applied to alfalfa (2017) but were applied to corn (2018; except SuperU) and barley (2019). Cumulative N2O-N losses over the 3-year rotation ranged from 2.8 to 5.2 kg/ha, with the fall and spring manure losing the greatest amounts of N2O-N. Emission factors indicated that -1.5 to 0.79% of the total N applied was lost as N2O-N during the growing seasons. Cumulative losses of CO2-C and CH4-C over the rotation were on average 12,170 and -0.77 kg/ha, respectively, with no significant differences among the treatments. Major N2O-N pulses were associated with early-season irrigation events and incorporation of fertilizer and manure, but overall fluxes tended to increase during the summer months when soil temperatures were highest. When accounting for increases in soil organic carbon (SOC) over the three growing seasons, the net GWPs were determined to be negative for the compost (-35.4), fall manure (-130.4), and spring manure (-48.9) treatments. As a result, these manure treatments should be considered as an alternative to synthetic N fertilizer use in southern Idaho due to their ability to increase SOC and help reduce agricultural climate impacts, while maintaining high crop yields.

Item Type: Article
NWISRL Publication Number: 1708
Subjects: Air Quality > Air Emissions
Irrigated crops > Corn / maize
Manure > Composted manure
Depositing User: Users 6 not found.
Date Deposited: 13 Jul 2021 14:00
Last Modified: 13 Jul 2021 14:00
Item ID: 1746