I generally do not concur with a lot of the suggestions put out here, mostly because they demand increasing sophistication through education which is simply impractical to provide anytime soon. I suspect the supposed benefit is in actual conflict with the farm economy itself and is far too easily set aside and represents only a temporary fix.
Good management must be taught and supported economically.
Far more important is the general implementation of terra preta methods on all crop lands. It is easily learned and immediately improves the farm economy and can even be made a requirement for farm lending by providing a value lift for measured terra preta.
It is the sort of incentive that will motivate millions to find ways to produce terra preta soil. The payoff is a permanently improved soil that eventually leaves of the use of any chemical fertilizers.
Otherwise, again we return to finding ways to reward competent forest management. There we need to harness current practices to be sustaining rather than exploitive. The best way there may simply be a community chipper allowing private owners to groom woodlands every year or so as needed. The chip production can then be reduced to salable charcoal in the same makeshift kiln that produces biochar.
The woodlots need to be individually owned for this to work well and banks can also encourage good management.
Changing tropical farming methods could cut emissions of methane and carbon dioxide by up to 417 Mt of carbon dioxide-equivalent by 2030, around 12% of livestock-related worldwide emissions of the greenhouse gases. That's according to a team from
Copenhagen and , who believe that the most likely levels of emissions cuts could be worth $1.3 bn a year. Kenya
"We should aim for fewer, better-fed, animals," Philip Thornton of the Program on Climate Change, Agriculture and Food Security at the University of Copenhagen, Denmark, and the International Livestock Research Institute (ILRI), Kenya, told environmentalresearchweb. "Apart from strategies to sequester greater amounts of carbon, all strategies for mitigating greenhouse gases appear to require the intensification of animal diets and a reduction in animal numbers to produce the same volume of meat and milk."
Burgeoning populations, increased incomes and urbanization mean that the demand for livestock products in developing countries is set to almost double by 2050. But livestock are estimated to contribute around 18% of man-made greenhouse-gas emissions worldwide; land-use change to produce animal feed and create pasture can emit carbon dioxide, manure and slurry can give off nitrous oxide, and ruminants themselves directly produce methane during their digestion process, belching it out into the atmosphere.
Thornton and colleague Mario Herrero of the ILRI looked at strategies for reducing emissions of carbon dioxide and methane from cattle farming in the tropics in mixed and rangeland-based systems. They examined approaches such as improving pasture by growing grass from the Brachiaria genus; feeding animals stover (leaves and stalks left over from crops, such as maize or soybean) that is more digestible; supplementing feed with grain; carbon sequestration by restoring degraded rangelands; increasing agroforestry, for example growing trees such as Leucaena to supplement animal feed and improve carbon storage; and switching to cross-bred cattle that produce more meat and milk.
The researchers found that mitigation strategies for livestock in the tropics could provide a maximum of 7% of the potential mitigation from livestock farming worldwide. Restoring degraded rangelands in sub-Saharan Africa and tropical Central and
South America appeared to have the highest mitigation potential, followed by agroforestry, then improved pasture and better stover digestibility.
"Ways to mitigate greenhouse gases in tropical livestock systems are technologically straightforward," said
. "Apart from strategies to sequester carbon, all strategies for mitigating greenhouse gases tested could be implemented at farm level with the appropriate economic and other incentives for resource-poor farmers." Thornton
reckons that the impact of any given livestock intervention in the tropics on mitigating total greenhouse-gas emissions will be small. "To make a difference, we will need to implement many interventions and do so simultaneously," he said. "Mitigation strategies can also support strategies to help smallholders adapt to climate change. Some interventions will serve to help people cope with more unpredictable and extreme weather. As an example, if a smallholder has some agroforestry on the farm, then even in dry years the trees may provide some feed for animals (and at times when there may be little or no crop residues to feed), while still sequestering carbon." Thornton
Thornton believes that many smallholders will need appropriate incentives, in addition to the increasing demand for livestock products, and more user-friendly technologies to make even straightforward changes in their production practices.
"Greenhouse-gas mitigation strategies can be pro-poor," he said. "Paying small-scale livestock farmers and herders for practices that help sequester carbon – under REDD [Reducing Emissions from Deforestation and
Forest Degradation] or similar incentive schemes – although not trivial in management terms, would help smallholders generate greater and more diversified incomes."
Now the team plans to assess some of the mitigation options at a household level to see how robust they are in relation to impacts on incomes, food security and environmental sustainability. "Smallholders' enterprises – crops, livestock, off-farm activities – may interact substantially, and even quite small changes to one enterprise may have repercussions for others, for example, is there adequate household labour available?" said Thornton.
The researchers reported their work in PNAS.
About the author
Liz Kalaugher is editor of environmentalresearchweb.