Regenerative farming can help grow food with less impact
Our pastoral soils tend to have as much carbon as they once did under forest, but concerns have been raised about carbon losses in some regions. Yet, we do still have two big problems.
First, the animals that efficiently digest tough plants – including cows, sheep, and goats – all belch the greenhouse gas methane. This is a direct result of their special stomachs, and chewing their cud. Therefore, farms will continue to have high greenhouse gas emissions per unit of meat and milk they produce. The recent Intergovernmental Panel on Climate Change (IPCC) report emphasised this, noting that changing diets can reduce emissions.
The second problem is worst in dairying. When a cow lifts its tail to urinate, litres of urine saturate a small area. The nitrogen content in this patch exceeds what plants and soil can retain, and the excess is lost to water as nitrate and to the air, partly as the powerful, long-lived greenhouse gas nitrous oxide.
Defining regenerative
Regenerative agriculture lacks a clear definition, but there is an opportunity for innovation around its core concept, which is a more circular economy. This means taking steps to reduce or recover losses, including those of nutrients and greenhouse gases.
Organic agriculture, which prohibits the use of antibiotics and synthetic pesticides and fertilisers, could potentially include regenerative agriculture. Organics once had the same innovative status, but now has a clear business model and supply chain linked to a price premium achieved through certification.
The price premium and regulation linked to certification can limit the redesign of the organic agricultural systems to incremental improvements, limiting the inclusion of regenerative concepts. It also means that emission studies of organic agriculture may not reveal the potential benefits of regenerative agriculture.
Instead, the potential for a redesign of New Zealand’s style of pastoral dairy farming around regenerative principles provides a useful example of how progress might work. Pastures could shift from ryegrass and clover to a more diverse, more deeply rooted mix of alternate species such as chicory, plantains, lupins and other grasses. This system change would have three main benefits.
Win-win-win
The first big win in farming is always enhanced production, and this is possible by better matching the ideal diet for cows. High performance ryegrass-clover pastures contain too little energy and too much protein. Diverse pastures fix this, allowing potential increases in production.
A second benefit will result when protein content of pasture doesn’t exceed what cows need to produce milk, reducing or diluting the nitrogen concentrated in the urine patches that are a main source of nitrous oxide emissions and impacts on water.
A third set of gains can result if the new, more diverse pastures are better at capturing and storing nutrients in soil, usually through deeper and more vigorous root growth. These three gains interrelate and create options for redesign of the farm system. This is best done by farmers, although models may help put the three pieces together into a win-win-win.
Whether you’re interested in local beef in Virginia, or the future of New Zealand’s dairy industry, the principles that define regenerative agriculture look promising for redesigning farming to reduce emissions. They may prove simpler than agriculture’s wider search for new ways of reducing greenhouse gas emissions, including genetically engineering ryegrass.
Source
https://theconversation.com/climate-explained-regenerative-farming-can-help-grow-food-with-less-impact-123090