Economic and environmental impact of double cropping winter annuals and corn using the integrated farm system model

Authors: RANCK, ERIC - Pennsylvania State University; HOLDEN, LISA - Pennsylvania State University; DILLON, JASMINE - Pennsylvania State University; Rotz, Clarence - Al; Soder, Kathy

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2019
Publication Date: 4/1/2020
Citation: Ranck, E., Holden, L., Dillon, J., Rotz, C.A., Soder, K.J. 2020. Economic and environmental impact of double cropping winter annuals and corn using the integrated farm system model. Journal of Dairy Science. 103:3804–3815. https://doi.org/10.3168/jds.2019-17525.
DOI: https://doi.org/10.3168/jds.2019-17525

Interpretive Summary: Dairy farmers face environmental restrictions, low profitability, and volatile milk and feed prices. A possible option to improve efficiency and profitability is to double crop small grains grown during the fall, winter and early spring months with corn silage grown during the summer. Double cropping can reduce environmental impacts by increasing feed production and nutrient cycling within the farm, and this may provide an increase in profitability. Large variation in weather, feed prices and production systems make it difficult to assess the benefits of alternatives in crop and feeding management in short-term studies. We used farm simulation to evaluate the long-term impact of double cropping on nutrient cycling, total feed cost, and farm profit as affected by feed prices and the percentage of corn land double cropped. We found that double cropping could benefit dairy farms in northern Pennsylvania when good crop production is maintained during a period with average to high feed prices. This information helps farm advisors make informed recommendations about double cropping for farms where profit margins are small and environmental restrictions are constraining.

Technical Abstract: Dairy farms have been under pressure to reduce negative environmental impacts while remaining profitable during times when milk and commodity prices were volatile. Double cropping has been promoted to reduce negative environmental impacts and increase total DM yield/ha. Three dairy farms that double cropped winter annuals and corn were selected from northern and western Pennsylvania. Data were collected from recorded crop and dairy records and financial data for 2016 and 2017. Farms ranged in size from 336 to 511 ha with 233 to 663 cows. Data were used to set parameters for the Integrated Farm System Model (IFSM), which was used to simulate eight scenarios for each farm: current operation, 0, 50, and 100% of corn land double cropped, 30% feed price increase (FPI) with and without double cropping, and 30% feed price decrease (FPD) with and without double cropping at the farm’s current level of double cropping. A 20-year period, using weather data representative of the actual farms, was used in the IFSM simulations to produce both financial and environmental results. Double cropping winter annuals and corn silage increased DM yield by 19%, when comparing 0 to 100% of the corn land double cropped. With all corn land double cropped, net return to management per unit of milk increased by 1.8%, N leached per year decreased by an average of 4.5%, and phosphorus (P) loss was reduced by an average of 9.2% across farms, When feed prices increased by 30%, double cropping increased net return over feed cost and net return to management by 2.2 and 3.5%, respectively, across farms. When feed prices decreased by 30%, double cropping increased net return over feed cost and net return to management by smaller amounts of 0.15% and 0.1%, respectively, across farms. The yield of winter annual silage needs to be sufficient to cover the expense of growing winter annuals, if double cropping is going to be profitable for dairy farms in these areas with short growing seasons.