A “Burning” Ecological Question

In western rangelands, the use of prescribed fire is a practice that can help control invasive weeds, improve forage quality, increase plant diversity, and maintain wildlife habitats. Although prescribed fire mimics the natural growth and regeneration cycle brought about by wildfires, some rangeland managers are reluctant to use it and opt to use mowing or grazing instead.

ARS scientists in Miles City, MT, decided to investigate the matter. They found that while mowing offered some benefits, prescribed fire proved better at rejuvenating the soil, eliminating combustible debris, and promoting the growth of nutrient-rich grasses for cattle.

More information can be found at https://www.ars.usda.gov/news-events/news/research-news/2020/ars-ecologists-address-a-burning-question/.

“Juicing” Alfalfa for a Sustainable Aquaculture

Cows and horses aren't the only fans of alfalfa. Yellow perch like it, too. ARS scientists in Madison, WI, are experimenting with alfalfa as a promising alternative to using fishmeal, a protein-rich ingredient in aquaculture feeds given to "farm-raised" finfish and shellfish.

There’s concern that increasing consumer demand for aquaculture products like these will outpace what the ocean's wild-caught stock of sardine, anchovy, menhaden and other small forage fish can supply as a fishmeal resource for aquafeeds. Nutritious, affordable, plant-based alternatives could help ease the burden on these forage fish populations, which are important members of the marine ecosystem and its inhabitants, particularly larger predatory species.

Read "Researchers are Juicing Alfalfa as a Next-Generation Aquafeed" to learn more.

Matching Milkweeds to Monarch Butterflies

Not all milkweeds are created equal when it comes to species of the native flowering plants that monarch butterflies like most. Now, ARS and university scientists in Ames, Iowa, have a better handle on the situation.

Their studies of nine milkweed species in critical breeding areas of the country show that female monarch butterflies prefer laying their eggs on certain milkweed species, but they don’t specialize in reproducing only on one kind. This knowledge is key to a broader national effort to reverse this iconic insect’s declining numbers through milkweed habitat restoration projects.

Read Which Milkweeds Do Monarch Butterflies Prefer? to learn more.

Rejuvenating Soil with Biochar

Long ago, the Amazonians discarded agricultural wastes like corn husks by burning or burying them underground. Today, a similar approach is taken to make a porous, charcoal-like substance called biochar from agricultural materials, including manure and wood chips.

Burning these materials in low-oxygen conditions creates the carbon-rich biochar, and—taking their cues from the Amazonians—ARS scientists in Corvallis, OR, are examining its potential to rejuvenate the soil, especially in degraded land areas like mining sites where high acidity and pollutants like heavy metals can stop or slow plant growth. Biochar may also help farmers reduce their need for fertilizers as well as handling wastes like chicken manure.

Read Exploring the Benefits of Biochar to learn more.

Hidden Valley Fescue

Livestock producers need improved and high-quality forage grass varieties that can support both cattle growth and milk production but also tolerate drought and cold. 

To meet those needs, ARS scientists in Madison, WI, evaluated and released “Hidden Valley” meadow fescue, a type of flowering grass that flourishes in a wide range of habitats across the midwestern U.S.  Cattle also digest “Hidden Valley” more easily than many other grazing grasses and can eat more of it, which leads to higher weight gain and increased milk production. 

Yakety Yak

In Clay Center, NE, ARS researchers and their partners have developed the most complete and correctly ordered genome sequence to date for yak and Scottish Highland cattle.  This genome sequence is one of the highest quality genome assemblies for any mammal, including human. 

As such, the general strategy and techniques developed for this cattle genome assembly will also likely improve the accuracy of genomic selection for all livestock and plant species.

* Image courtesy of Getty Images

New Fish in the Water

Commercial salmon farming in the U.S. is expected to exponentially increase in the next few years, which will strain the Atlantic salmon industry.  To support that growth, ARS researchers in Franklin, ME, have bred an improved salmon strain and shared the eggs with commercial fish farms. 

This new salmon features increased growth, enhanced processing characteristics, and improved disease resistance – all factors that will improve the industry’s production efficiency and promote sustainable aquaculture. 

Hammer-time

Some herbs and vegetables we love to eat grow from extremely small seeds, like the size of a salt grain.  Planting these small seeds with precision can be expensive. 

In Salinas, CA, ARS developed a simple hand-operated planter, “Slide Hammer Seeder,” which can efficiently seed a variety of small-seeded herbs and vegetables. 

The Slide Hammer Seeder can be assembled using simple materials, and is useful for both farmers and home gardeners to more precisely grow their fruits and vegetables. Watch the video to learn how.

* Image courtesy of USDA

This is Exhausting

Farmers and growers typically combat weeds with chemical herbicides or manual removal, but those methods can be expensive, harmful to the environment, and labor intensive. ARS researchers in Auburn, AL, prototyped an innovative method to control weed growth by simply using engine exhaust heat.

The process involves a mechanical pusher that uses exhaust heat produced by a walk-behind tractor’s engine. The heat does not burn up the weed, but instead damages the plant tissues within the weed, killing the unwanted vegetation.

* Image courtesy of Getty Images

Eating Our Way to Fire Mitigation

ARS researchers in Boise, ID, have developed innovative methods to mitigate fires that are exacerbated by the increasing presence and dominance of weedy, highly flammable grasses. ‘Target grazing,’ involves strategically using cattle to graze on vegetation that is prone to catching and fueling fire.

Target grazing will simultaneously help to control invasive grasses without the use of chemical removal methods, reduce fire risks in wildland-urban interfaces, and effectively feed livestock in a sustainable manner.