The dairy forage rotation: Effects on farm carbon balance and soil health

Authors: Duff, Alison

Submitted to: Forage Focus
Publication Type: Trade Journal
Publication Acceptance Date: 3/1/2023
Publication Date: 3/15/2023
Citation: Duff, A. 2023. The dairy forage rotation: Effects on farm carbon balance and soil health. Forage Focus. March 2023 pg 4-5.

Interpretive Summary: Farm carbon balance provides a snapshot of greenhouse gas emissions and carbon storage at the farm scale. This requires assessment of the entire farm system, including estimates of emissions from all farm components: field, feed, herd, manure handling, and farm energy use. Given the scope of the net zero challenge, it is worth asking: What climate-smart farming practices are available to producers now? Including alfalfa, a deep-rooted perennial legume, in the dairy forage rotation is a viable strategy for reducing soil carbon loss. Management practices which minimize soil compaction, promote alfalfa root development, and allow for greater residues going into the winter season may improve alfalfa carbon balance in older stands. Compared to fields managed in continuous corn silage or corn-soybean rotation, dairy cropping systems which include alfalfa can improve soil structure in addition to improving field carbon balance. There is also evidence that diverse rotations are more resilient to extreme weather events.

Technical Abstract: Farm carbon balance provides a snapshot of greenhouse gas emissions and carbon storage at the farm scale. This requires assessment of the entire farm system, including estimates of emissions from all farm components: field, feed, herd, manure handling, and farm energy use. Given the scope of the net zero challenge, it is worth asking: What climate-smart farming practices are available to producers now? Including alfalfa, a deep-rooted perennial legume, in the dairy forage rotation is a viable strategy for reducing soil carbon loss. Management practices which minimize soil compaction, promote alfalfa root development, and allow for greater residues going into the winter season may improve alfalfa carbon balance in older stands. Compared to fields managed in continuous corn silage or corn-soybean rotation, dairy cropping systems which include alfalfa can improve soil structure in addition to improving field carbon balance. There is also evidence that diverse rotations are more resilient to extreme weather events. There is no one-size-fits all solution to improving farm carbon balance, and strategies should be adapted to the farm operation. This will likely include interventions in the barn, manure and feed management systems, and farm land base. In the field, increasing cropping system diversity is an important practice in any dairy operation. There will likely be multiple paths to “net zero,” and dairy producers have the opportunity to lead the agricultural sector in addressing climate change.