Farm and Field

Researchers look to switchgrass to boost air quality

By Herald-Whig
Posted: Oct. 29, 2017 12:01 am

Researchers from the United States and China have proposed an idea that could improve China's air quality, but they're not atmospheric scientists. They're agronomists.

"China's poor air quality is caused by a combination of coal burning and particulates from soil erosion. If erosion in the Loess Plateau can be improved, air quality will improve," said D.K. Lee, an agronomist in the Department of Crop Sciences at the University of Illinois.

Although the region has been farmed for millennia, much of China's Loess Plateau could be described as a barren moonscape: dry, dusty and prone to erosion. In fact, the distinctive loess soils in the area have been called the most erodible in the world.

In a massive soil conservation effort, the Chinese government is creating incentives for farmers to plant sustainable and erosion-reducing cropping systems including orchards, forests and perennial grasses. Researchers from U of I are recommending switchgrass.

"When we're looking at revegetation, ideally we're planting something that can bring in revenue for farmers. Switchgrass produces a lot of biomass that can be harvested and burned as a cleaner source of energy," Lee said. "Not only can switchgrass reduce air pollution by holding the soil, if it is burned instead of coal, it can reduce air pollution in a second way."

Switchgrass is stress tolerant, and small-scale testing in the area has shown that it can produce plenty of biomass even with limited irrigation and fertilizers. But Lee said cultivar selection and management practices will depend on where switchgrass is planted within the Loess Plateau.

Although switchgrass has been introduced in China, it hasn't caught on as a biomass crop yet. That's where the research team -- including experts in switchgrass cultivar selection, agronomy and management -- comes in, and their article published in the Journal of Integrative Agriculture provides information in practical terms for future evaluation by Chinese scientists and government agencies.

Steer prices

Steep price swings were seen for fed steers in the past year. Look for more of that in beef in coming months with lower prices ahead, but annual average prices for 2017 can end near last year's with declines resuming in 2018.

Domestic demand and exports help prices in the face of growing supplies, University of Missouri Extension economists Scott Brown and Daniel Madison said.

Prices swung from below $1 per pound in mid-October 2016 to near $1.45 per pound in May. Prices softened because summer grilling ends, cutting demand, and because of large cattle-on-feed supplies.

A bright spot in beef supplies comes as feed yards send cattle to market at lighter weight, which cut meat tonnage. With recent higher prices, feeders pushed cattle forward faster.

Slaughter weights continue to trail year-ago levels, but expect weights to regain in 2018. "That'll add only modest tonnage as more cattle go to market," Brown said.

Projected U.S. beef cow herd growth continues through 2019. Cows will reach 31.8 million head, up from 31.1 million. By 2022, the herd will drop back to 31.1 million.

Help for producer prices came from surprising growth in demand for quality beef. August saw record-high prime-choice price spreads for boxed beef. At times, buyers paid more than $55 per hundredweight premiums for top-grading USDA prime.