Project Drawdown ranks regenerative agriculture 11th, achieving an estimated 23.15 gigatonnes of CO2 equivalents by 20150. This increase is based on increasing land currently managed using regenerative agriculture from 108 million acres (43.7 ha) to one billion acres (404 million ha). Other agricultural drawdowns can be achieved by the solutions listed here.
The world cannot be fed unless the soil is fed. Regenerative agriculture enhances and sustains the health of the soil by restoring its carbon content, which in turn improves productivity—just the opposite of conventional agriculture.
Drawdown reports that regenerative practices are raising soil carbon levels from one or two percent to eight percent over ten or more years.
In the Drawdown project, regenerative agriculture focuses on crop production. For Northland our focus is on pastoral farming. Here is a summary of the industry from Northland Inc.
There are 735,400 hectares of land in pasture in Northland, more than half the regions 1.42 million hectares.
Northland accounts for 7% of the nation’s dairy cows, 8% of the dairy land (144,345 ha) and 9% of the dairy herds. The value of milk generated in the 2013/2014 season was $867 million.
As at June 2016 there were 356,823 total beef cattle and 366,197 total sheep in Northland (Stats NZ). Northland produces 20% of New Zealand’s beef.
Follow these links for a overview of regenerative agriculture practices for dairy and dry stock (sheep and beef).
Methane and nitrous oxide
The agriculture sector generates the highest percentage of New Zealand’s gross CO2 equivalent emissions – 49% followed by 40.5% for the energy sector (Ministry for the Environment, 2015 data). There is no sign of any significant reduction.
New Zealand’s gross greenhouse gas emissions by sector from 1990 to 2015 (Ministry for the Environment, 2015, page 3)
Agricultural emissions come mostly from methane and nitrous oxide. In 2015, 76.1% of agricultural emissions (CO2 equivalents) came from methane, 20.8% from nitrous oxide and 2.9% from CO2. The global warming potential of methane (over 20 years) is 56 x that of CO2. Nitrous oxide has 280 x the potency of CO2. (NNFCCC)
Methane
In the rumen, one of the four stomachs of ruminant animals, gasses are produced by microbial fermentation. Methane is 26.8% of those gasses, contributing to 20% of agricultural emissions. Manure management accounts for another 7% (Penn State University). Farms providing ideal conditions for animals reduce methane emissions proportionally by more efficient milk or meat production. Other solutions include the quality of feed and science-led interventions of the digestive processes.
Organic farming methods can significantly reduce methane emission from manure primarily because of dry manure management methods. By contrast, intensive farming systems that use wet manure management systems generate more methane through anaerobic decomposition (The Organic Center).
Nitrous oxide
Nitrous oxide emissions have increased about 40 to 50% over pre-industrial levels. Globally, agriculture accounts for 67% of human generated nitrous oxide.
The use of synthetic fertilizer for agriculture is a major source of nitrous oxide emissions. Fertilizers help feed plants by adding nitrogen directly to soils. But soil bacteria also take advantage of this extra nitrogen and use it to produce the energy they need to live and grow. Microbial processes of nitrification and denitrification produce nitrous oxide which is then released into the atmosphere. Similarly, the use of manure as a fertilizer also leads to emissions from agricultural soils. Nitrous oxide can be created rapidly when soils are warm and moist while also containing a ready supply of reactive nitrogen (What’s Your Impact) .
This World bank website reports nitrous oxide emissions and methane emissions globally and by country.
With half of our land used for livestock we have a great opportunity in Northland to reduce emissions and sequester more carbon.
Organic agriculture for regeneration
The quote above, from Drawdown, warrants repeating. “The world cannot be fed unless the soil is fed. Regenerative agriculture enhances and sustains the health of the soil by restoring its carbon content, which in turn improves productivity—just the opposite of conventional agriculture”.
This table from the FAO shows pathways of organic agriculture to directly or indirectly reduce agricultural greenhouse gas emissions.
Additional links
Sam Lang’s Nuffield Scholarship on regenerative agriculture.
Aotearoa Food Policy Network 