Well-established ‘Holos’ program estimates current on-farm emissions and demonstrates how changes in practices reduce them.
To test possible ways of reducing whole-farm greenhouse gas (GHG) emissions, farmers around the world can use Holos, a software program that’s available free of charge and in English and French. Holos was developed in Canada.
Once users download the program, they select the scenarios and management practices that best match what they are already using on their farms, then make adjustments to see how much emissions can be reduced. Adjustments could include changing livestock feed, reducing tillage or including perennial forages in rotation.
Holos estimates carbon dioxide, nitrous oxide and methane emissions. It also provides a look at carbon storage and loss from taking actions such as planting trees and changing land use in other ways. The most-recent version, 3.0.6, also includes a basic economics cost/benefit analysis and the ability to input farm details in Imperial units (metric input was included from the beginning).
In a recent Holos fact sheet, an example of how the program can help farmers with whole-farm GHG emissions ‘thinking’ is illustrated. For a beef producer who switches from planting an annual grass forage to a perennial legume forage, Holos shows how net emissions are reduced in several ways.
Because legumes are nitrogen-fixing crops, the need for nitrogen fertiliser is reduced. That means the energy that would have gone into producing that amount of fertiliser (as well the CO2 emissions from the production process) is saved. In addition, N loss to the air and water are reduced.
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In addition, in this example scenario, transitioning annual crops to perennial forages incorporates carbon into the soil. Fuel and machine usage is also reduced, as perennials do not require yearly re-seeding etc.
Another reduction in GHG impact for this example farm is found in that bioactive compounds in certain legume forages can decrease N losses through cattle urine and enteric methane production.
In 2020, a graduate student at Utah State University used Holos and another modelling software system called COMET-Farm to look at aggregate GHG emissions.
Holos is available for download here. If you have feedback or want more information, contact the Holos team: Holos@agr.gc.ca
For a list of other environment-related farm tools, visit the US Department of Agriculture list here.