Research solidifies cattle’s role in soil health

A British scientist argues that higher stocking rates and uniform distribution of animals lead to better soil structure

LEXINGTON, Ky. — Long-term grasslands studies have made researchers like Taro Takahashi a believer in the environmental value of livestock and grazing.

Takahashi is a research scientist whose work at Rothamsted Research in Hertfordshire, England, includes a life-cycle assessment of pasture-based cattle production systems.

Rothamsted Research is one of the oldest agriculture research institutions in the world, and since 1856 the Park Grass Experiment has been testing the effect of fertilizers and manure on hay fields and soil health. Scientists at this facility are also conducting long-term studies on what might happen if livestock was removed from the landscape.

The study has looked at soil health and cattle performance when the two work together.

“It is all good we think, but not everybody is happy about grazing because of livestock emissions,” he said at the international Alltech conference held at Lexington this spring.

He argues manure is an important part of sustainable arable systems. Many, but not all, intensive arable systems are mining the nutrient stock out of the soil.

“There are many places in the world where you wish your soil was better,” he said.

There are other benefits where researchers have shown live weight gain is related to soil health. Good productive soil grows more plants and adds weight to grazing animals.

“When you have a higher stocking rate and uniform distribution of animals, then that leads to better soil structure,” he said.

Manure and grazing activity adds more soil organic matter with improved water-holding capacity. This practice is especially valuable on mixed farming operations.

There is also a social benefit.

Beef is a nutrient dense food for people who consume it but there is a movement in the United Kingdom to tax meat and dairy at a rate of 18.6 percent to cut emissions that contribute to climate change. That tax is the equivalent of $52 per tonne of carbon emitted.

He questioned the fate of the rural economy if the beef sector was taxed out of business.

“They do not talk about the negative consequences. They do not think what would happen to rural society if they do so,” he said.

“The economy would shrink. That shrinkage is bigger than the environmental benefit we might enjoy from reduced carbon emissions.”

Producers might switch to cereal crops on former grasslands, which Takahashi argues is not the best use of the land. For example, western England has marginal land with heavy clay soils best suited to growing grass rather than cereal crops. Post-veganism land use would see no manure for soil amendments and no feed crops in rotation.

“When all things are considered, pasture-based livestock systems are the socially optimal end use for regions, especially where the land base is unsuitable for human edible crops,” he said.

Frank Mitloehner, a professor and air quality specialist at the University of California, Davis, is another supporter of livestock’s environmental contribution.

“Many people in agriculture doubt the existence of climate change. There is no doubt that climate change exists,” he said.

Doing away with livestock production to stop environmental degradation is a bad idea, he said

Two-thirds of agriculture land in the world is considered marginal and cannot grow crops well so the land is used for grazing livestock.

“By getting rid of ruminant livestock we would not make use of 70 percent of all agriculture land,” he said at the Alltech conference. While some say they want an organic, vegetable-based diet, livestock manure is part of the equation.

“Without animals there are no organic fertilizers.”

Recently the University of Arkansas analyzed the environmental footprint of beef cattle production with funding from the National Cattlemen’s Beef Association and United States government.

Most people believe feedlot cattle in confinement have the greatest impact on the environment but the study found the cow-calf sector has the largest footprint. Cattle spend the vast majority of their lives on pasture but the news from the study shows that is not a bad thing.

The study found fresh water required to produce a kilogram of beef ranges from 200 to 5,800 litres depending on the region and production system. Most goes through feed.

Total greenhouse gas emissions showed 3.3 percent of all emissions stem from the beef industry. This is slightly higher than federal government numbers of two percent but this research summarized all parts of the beef supply chain from belching, transportation at different stages and production, said Mitloehner.

Industries like cement, energy generation and all fossil fuel uses are responsible for 80 percent of emissions. Among fossil fuel users the beef system consumes about 0.7 percent.

It takes 2.6 units of grain to get one unit of beef throughout the lifetime of an animal from birth to slaughter. While cattle consume a lot of feed, they take in inedible grass and upgrade it into highly digestible protein and other products.

“Our results suggest that each individual beef sector and the entire value chain can produce more high quality protein than is consumed in production,” he said.

The complete study may be viewed here.

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