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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Agroecosystems Management Research » Research » Publications at this Location » Publication #340121

Research Project: MANAGING AGRICULTURAL WATER QUALITY IN FIELDS AND WATERSHEDS: NEW PRACTICES AND TECHNOLOGIES

Location: Agroecosystems Management Research

Title: Harvesting fertilized rye cover crop: simulated revenue, net energy, and drainage Nitrogen loss

Author
item Malone, Robert - Rob
item OBRYCKI, JOHN - Orise Fellow
item Karlen, Douglas
item Ma, Liwang
item Kaspar, Thomas - Tom
item Jaynes, Dan
item Parkin, Timothy
item LENCE, SERGIO - Iowa State University
item Feyereisen, Gary
item FANG, Q - Qingdao University
item Richards, Thomas
item Gillette, Katrina

Submitted to: Agricultural and Environmental Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2018
Publication Date: 1/25/2018
Citation: Malone, R.W., Obrycki, J., Karlen, D.L., Ma, L., Kaspar, T.C., Jaynes, D.B., Parkin, T.B., Lence, S., Feyereisen, G.W., Fang, Q., Richards, T.L., Gillette, K.L. 2018. Harvesting fertilized rye cover crop: simulated revenue, net energy, and drainage Nitrogen loss. Agricultural and Environmental Letters. 3:170041. https://doi.org/10.2134/ael2017.11.0041.
DOI: https://doi.org/10.2134/ael2017.11.0041

Interpretive Summary: Food and biofuel production along with global N use are expected to increase over the next few decades, which complicates the goal of reducing N loss to the environment. Including winter rye as a cover crop in corn-soybean rotations reduces N loss to drainage. A few studies suggest harvesting rye as a biofuel feedstock is a promising method to provide producer income and increase biofuel production without decreasing food production, however, the impact on N loss to drainage is unknown. Using the Root Zone Water Quality Model (RZWQM), we estimate 100 kg N/ha as the optimum fertilizer rate applied to rye prior to soybean planting. At the optimum fertilizer rate, $269/ha in added revenue was estimated from 5.4 Mg/ha harvested rye prior to soybean planting. Drainage N loss at the optimum N rate was reduced 40% compared to not including winter rye in the corn-soybean rotations. These results suggest double-cropping fertilized winter rye is a promising strategy to provide revenue and reduce N loss to drainage. With additional potential revenue from harvested winter rye and reduced N loss to drainage, including fertilized and harvested winter rye into corn-soybean rotations may have greater societal and producer net benefits compared to not including winter rye. This research provides agricultural scientists a potential avenue of study because these modeling results will need to be verified by field studies. Producers may be interested in the additional revenue potential of harvesting a rye winter cover crop. Lastly, policy makers may be interested in this research because it identifies a promising practice to increase biomass production and reduce N loss to the environment without decreasing food production.

Technical Abstract: Food and biofuel production along with global N use are expected to increase over the next few decades, which complicates the goal of reducing N loss to the environment. Including winter rye as a cover crop in corn-soybean rotations reduces N loss to drainage. A few studies suggest that harvesting rye as a biofuel feedstock is a promising method to provide producer income and increase biofuel production without decreasing food production, however, the impact on N loss to drainage is unknown. Using the Root Zone Water Quality Model (RZWQM), we estimate 100 kg N/ha as the optimum fertilizer rate applied to rye prior to soybean planting. At the optimum fertilizer rate, we estimate $269/ha in added revenue from 5.4 Mg/ha harvested rye prior to soybean planting. Drainage N loss at the optimum N rate was reduced 40% compared to not including winter rye in the corn-soybean rotations. These results suggest double-cropping fertilized winter rye is a promising strategy to provide revenue and reduce N loss to drainage.