CLIMATE CHANGE AND GRAZING
Efforts to reduce greenhouse gas emissions – while absolutely necessary – are not enough to address the climate change that is already under way. Now it is urgent that we pull carbon from the atmosphere and store it safely, deep beneath the surface of the soil, utilizing photosynthesis and other natural systems that are already proven and at hand. See a report on the net climate benefit of rotational grazing.
For decades farmers in the US have plowed up ground to plant corn, which has allowed soil carbon near the surface to oxidize. (About 40% of this corn is used for livestock feed.) To reverse the damage done by industrial agriculture, we must (1) feed cattle (and other ruminants) grass, not grain, and (2) manage pasture with rational grazing, which increases carbon sequestration.
Arguably the most effective climate activists are the smallest: mychorrizal fungi and associated bacteria. As the plants take in carbon from the air, microbes in and around the roots pass some of that carbon from the plants to the soil, where it is stored in waxy structures called glomalin, produced by the Glomales fungi. Rotational grazing results in greater soil carbon concentrations than conventional grazing or no grazing. (See also, Soil, Water, & Grazing.)
The photo at left shows soil samples almost 20 inches deep taken from two pieces of land divided only by a fence. The levels of carbon in both pieces were originally the same, but changed dramatically after two brothers subsequently managed their respective pieces in different ways for 10 years.
The sample on the left was taken from the piece that was managed with rotational grazing and other practices that allow maximum photosynthesis; this sample shows that 50 centimeters of carbon-rich topsoil formed in the 10-year period. Note the darker color.
On the land represented by the sample on the right, photosynthesis was held back by applications of super-phosphate fertilizer, removal of perennial ground cover, and conventional grazing management. All of these practices destroy the microbes that sequester carbon. (Photo and data courtesy of Dr. Christine Jones, soils ecologist.)
METHANE: GRASS-FED VS. CONVENTIONAL BEEF PRODUCTION
Much of the information circulating about the contribution of cattle methane to climate change may be true for conventionally raised cattle but is not true of 100% grass-fed beef cattle for several reasons:
1. Bovines raised in a well-managed, rotational system eat higher-quality forage than cattle raised conventionally; leafy, productive plants offer the cattle higher nutrition. According to Dr. Richard Teague, a range ecologist at Texas A&M, cattle digest higher-quality forages more quickly, lowering the amount of methane that the animal generates.
2. Also important for combatting climate change are methanotrophic bacteria, which utilize methane as their sole energy source. They are found in pasture soil, and as the cattle graze, these bacteria oxidize some of the methane that the cattle emit. This beneficial service does not occur in a feedlot.
3. In addition, because grass-fed beef are not confined, they drop their manure evenly over grasslands. In comparison to manure that is concentrated by confinement systems and stored or treated as a liquid, manure deposited in the pasture emits less methane.
4. Most studies done on the climate impact of raising cattle do not factor in the carbon sequestration that occurs when cattle are grass-fed throughout their lives, as described above - which results in a net climate benefit of grass-fed beef production.
*“...they stick a cow in a small, airtight, little box and feed her, water her and measure her emissions. Then they deduce this is what’s causing all the problems in the world without taking into account the whole environment cows live in.”
- Richard Teague, PhD, in an interview with Progressive Farmer
COMPARING AG INPUTS
Aside from the critically important factors of carbon sequestration and decreased methane generation associated with grass-fed beef production, there are other inputs to consider when calculating the carbon footprint. For example, the corn-based diet of conventional cattle is produced with heavy fossil fuel inputs, notably from synthetic fertilizers and diesel-fueled tractors and other equipment utilized in the production, processing, and storage of corn.
In contrast, our grass-fed beef is based on solar energy, natural systems, and low- tech infrastructure. For example, flexible fencing and a tumble-wheel (illustrated here) allow beef cattle to move across our pastures, similar to the way that herds of ruminants - buffalo, reindeer, caribou, antelopes, etc. - once roamed grasslands worldwide.
HOW BIG PICTURE BEEF COMBATS CLIMATE CHANGE
These practices help sequester carbon and reduce emissions:
- We graze our cattle in a rotation of paddocks that allows manure to be evenly distributed over the land, instead of accumulating and emitting methane
- We allow the grass and other pasture plants to grow tall and roots to go correspondingly deep, which keeps carbon locked in the soil.
- We disturb the soil as little as possible to allow microbial life to transfer carbon from the plant roots to the soil; for cover crops we use a no-till seeder.
- We do not use pesticides and herbicides such as glyphosate (Roundup), which destroy the soil food web upon which critical natural systems depend.
- We do not use chemical fertilizers, which accelerate carbon loss from the soil.
In summary, 100% grass-fed cattle cannot be charged with contributing to climate change. In fact, practices that enhance - rather than inhibit - natural soil systems improve the capacity of farmlands to sequester carbon and to act as a methane sink. Thus, 100% grass-fed beef offers an important strategy for combatting climate change while providing protein for growing populations.
Soil Solutions to Climate Problems - Four-minute video (below) narrated by Michael Pollan.
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