Drought prompts experiments with rice straw


Issue Date: September 24, 2014
By Ching Lee
Glenn County farmer Darrin Eden, standing next to his straw baler, is baling rice straw at a higher moisture level, when the byproduct is still green.
Photos/Ching Lee
Baling rice straw at a higher moisture level, when the byproduct is still green.
Photos/Ching Lee
More California rice farmers are expected to bale their rice straw this fall because many fields won’t have water available to help them decompose the straw after harvest.
Photo/Ching Lee

Typically considered an inexpensive, low-quality livestock feed, rice straw is getting special treatment this year, as more growers experiment with new ways of baling it to try to retain more of its nutritional quality.

The need for the experiment is twofold: Livestock feed has been in short supply due to the drought. Water shortages will also create problems for rice growers this fall, as many areas will not have water available to decompose rice straw after harvest, leaving an abundance of the byproduct in the field.

Because air quality regulations have limited growers' ability to burn the straw, many say they will likely bale more of it this year. The straw has a variety of uses, including for cattle feed, livestock bedding, erosion control, building construction and mushroom production.

Ranchers have used rice straw as feed for years, mainly as a filler to stretch higher-quality feeds. But with the drought, ranchers have had to feed much more of it, said Larry Massa, a cattle rancher and rice grower in Glenn County.

"There's not a whole lot of nutritional value to rice straw, but it does fill the calves' stomachs up," he said. "When you're feeding better-quality forages, you can mix some of that in."

Traditionally, rice growers bale the straw when it's dry, several days after harvest. But when the straw dries, it also loses its nutritional value, researchers at the University of California found. They knew that baling the straw immediately after harvest at a higher moisture content—50 percent to 60 percent—would make the straw more nutritious and digestible for cattle, but there was concern that the high moisture would cause mold and spontaneous combustion in the bales.

To prevent these problems, UC Cooperative Extension advisor Glenn Nader recommends covering the straw bales with a tarp and treating the straw with propionic acid to control fungal growth. But he acknowledged that farmers and ranchers "aren't real wild about dealing with tarps and trying to keep them on." The tarp material also would add $2.40 per ton to their cost, he noted.

"The one downside of this whole thing is you're hauling 50 percent moisture, so that's a problem," said Josh Davy, a UCCE livestock, range and natural resources advisor for Glenn, Colusa and Tehama counties.

He noted that hay is usually baled at about 15 percent moisture, so it's more efficient to stack and haul, whereas wetter rice straw makes the bales limp, heavy and more problematic to transport.

Instead of baling the straw at the UC-recommended moisture level and making what Nader calls "strawlage," some farmers are putting their own twist on the method.

Darrin Eden, a Glenn County farmer who also does custom harvesting and baling for other farmers, said he has been baling some rice fields at just below 27 percent moisture, which is wetter than usual for baling rice straw but not as wet as Nader's strawlage. He's also treating the straw with propionic acid but forgoing the tarp.

Eden said he's baled plenty of dry rice straw in the past, but this is his first year doing it this way and using propionic acid, which is also used in other stored hays, grains and grass crops. His hope, he said, is that the preservative will work just as well on rice straw.

"It's trying to figure out how to make the cattle eat (the straw) better," he said. "The cost of feed is really high, and any byproduct that you can get that fills a gap at a lower cost will help."

Davy said Colusa County rice grower and rancher Doug Parker is trying yet another variation of the strawlage idea by baling the straw at 30 percent moisture and then wrapping the bales in plastic, which he said is a good way to retain the straw's moisture while saving time and labor. But he noted Parker uses a special implement called a bale wrapper to do this, and the bales are stacked in long rows rather than on top of each other, so this method requires more land space than some operations may have.

Because strawlage is a challenge to move, Davy said he thinks it'll mainly be used as a range supplement by local ranchers, unless feed prices continue to skyrocket and there are no other alternatives.

"We have plenty of market to be able to use this," he said. "There are enough cattle on rangeland around these rice fields that need feed, and that's where this can work."

The idea of baling rice straw at high moisture actually started with Yuba County rancher Henry Smith, whom Nader described as the "grandfather of rice strawlage." Smith said he's been experimenting with feeding rice straw for more than 10 years, trying to make it a better feed, and was influenced by how dairy farmers make corn silage. He said he figured if he could duplicate the results, then the straw would be more digestible for cattle.

He said he gets calls from farmers "all the time on how to do it," and insists the "right way" to do it is baling the straw at 50 percent to 60 percent moisture.

Nader said UC researchers will be collecting and analyzing nutritional data from various producers feeding rice straw but who are baling it differently from the UC-recommended method. He said he thinks much will be learned this year.

Butte County rancher Chris Donati said while rice straw will never replace alfalfa hay and other high-quality forages, he thinks it could be a valuable feedstock not only during times of drought but in winter months such as December and January, when grasses are not growing.

"I think it's an idea that has great promise," he said. "I don't know the industry has it fully ironed out quite yet, but I would like to think that within the next several years, through the hard work of innovators like Henry Smith and the continued work of guys like Darrin (Eden), we'll be able to optimize what potentially could be a good tool for those of us in Northern California."

(Ching Lee is an assistant editor of Ag Alert. She may be contacted at clee@cfbf.com.)

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.