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WSU’s Green Times – Sustainable Fertilizer, Rain Gardens, Biodegradable Mulch, Enviro Education – March 21, 2013

Posted by | March 21, 2013

Comprehensive Effort to Create Sustainable Fertilizers

Phosphorus recycled from human and animal waste for plant fertilizer could ease demand for the dwindling, increasingly expensive rock-mined element. Scientists at WSU have found plants flourish with struvite, a waste ingredient composed of magnesium, nitrogen, and phosphorous. Teamed with Multiform Harvest, a Seattle phosphorous recovery company, the researchers are fine-tuning the application and proportion of essential components in the fertilizer with the goal of marketing a product and ultimately adding security to the world’s food supply.

Adding fertilizers to marigolds and peppers in the greenhouse.
Adding fertilizers to marigolds and peppers in the greenhouse.

“You can’t continue mining a finite resource forever,” said Rita Hummel, a scientist at the WSU Puyallup Research and Extension Center. “But as long as we can reclaim struvite from animal manure and sewage, we have a sustainable resource. We’re figuring out how to use it effectively and safely.”

Local Benefits

Hummel is using Multiform Harvest struvite from wastewater treatment plants at Yakima, Washington, and Boise, Idaho. She and her fellow researchers hope to include struvite extracted from manure from area dairy farms to develop regional nutrient recycling.

“When you feed a cow, about 20 to 25 percent of the phosphorus the cow eats ends up in the milk carton,” said Joe Harrison, Hummel’s scientist colleague at WSU. “That means about 75 to 80 percent ends up in the manure.”

Marigold from early experiments with (l-r) no phosphorus, struvite, and triple superphosphate.
Marigold from early experiments with (l-r) no phosphorus, struvite, and triple superphosphate.

Hummel is using Multiform Harvest struvite from wastewater treatment plants at Yakima, Washington, and Boise, Idaho. She and her fellow researchers hope to include struvite extracted from manure from area dairy farms to develop regional nutrient recycling. “When you feed a cow, about 20 to 25 percent of the phosphorus the cow eats ends up in the milk carton,” said Joe Harrison, Hummel’s scientist colleague at WSU. “That means about 75 to 80 percent ends up in the manure.”

Not only could reclaiming struvite from waste localize production and distribution, it could also help mitigate water pollution problems such as overloading phosphorus in agricultural soils. “The research being performed at WSU is central to us generating the hard data we must have to get this recycled phosphorus into the agricultural market, from large fields to specialized greenhouses and nurseries,” said Kevin Fullerton, product developer for Multiform Harvest.

Encouraging Results

Tomato from early experiments with (l-r) no phosphorus, struvite, and triple superphosphate.
Tomato from early experiments with (l-r) no phosphorus, struvite, and triple superphosphate.

In previous greenhouse crop studies, Hummel discovered struvite had a similar effect on plants as the commercial phosphorus source, triple superphosphate. Crops like basil, cucumber, marigold, and tomato barely sprouted without phosphorus, but flourished with struvite from King County municipal wastewater.

With support from a USDA small business innovation research grant, Hummel will experiment with different rates and ways of applying the struvite–adding it to the potting mix, sprinkling it on the surface, and placing it beneath the plant–to determine the rate at which it is released.

“One of the things we need here in western Washington is a slow-release product so it doesn’t leach out the bottom of pots and run down drains and into streams, rivers, and the Puget Sound,” Hummel explained.

Reliable Recycling

Most phosphorus in the United States comes from Florida, but this production could decline sharply in the next 30 years, Fullerton said. Current practices indicate such a loss would lead to dependence on the other known stockpiles in Morocco, China, South Africa, and Jordan.

“If we can take a waste disposal problem and turn it into a fertilizer that actually replaces something we have to mine and are running out of-–that’s sustainability,” Hummel said.

-Rachel Webber

Rain Garden Mentors Help Put a ‘LID’ on Stormwater Runoff

Stormwater runoff is the number one cause of pollution in Puget Sound – it’s not good for fish and wildlife and it’s not good for people. Every time it rains, polluted runoff washes into streams and rivers and, ultimately, the Sound.

Thanks to the inaugural graduating class of WSU Rain Garden Mentors, homeowners in Clallam County will soon have more options for protecting Peninsula creeks, the Strait of Juan de Fuca, and Puget Sound from stormwater pollution. Rain Garden Mentors will begin reaching out to Clallam County homeowners starting in May.

Rain gardens are beautiful landscape features that mimic natural processes to help filter and slow stormwater that flows off roofs, driveways, patios, and landscapes before it enters Puget Sound. Planted with native plants and flowers, rain gardens also attract birds, butterflies, and wildlife. Rain gardens are part of a suite of techniques for managing stormwater runoff called low-impact development (LID).

Matches Made in Rain Garden Heaven

The City of Port Angeles encourages homeowners to install rain gardens and other stormwater filtration systems and even discounts part of their utility bill for doing so. WSU Rain Garden Mentors provide rain garden installation and planting advice while the City of Port Angeles provides incentives and engineering expertise.

A newly planted and established rain garden, in Puyallup, WA. Photos courtesy Rain Dog Designs, LLC.
A newly planted and established rain garden, in Puyallup, WA. Photos courtesy Rain Dog Designs, LLC.

Jonathan Boehme, a City of Port Angeles Stormwater Engineer, is enthusiastic about the partnership with WSU. “We’re just on the beginning of the LID wave,” Boehme said. “This summer we have a proposed rain-garden rebate program that would provide a $250-$500 rebate for the cost materials.” According to Boehme, Port Angeles has plenty of existing infrastructure (homes and buildings) and not a lot of new development where LID techniques can be implemented. Getting existing homeowners excited about installing rain gardens is where the opportunity for real impact lies. “Rain Garden Mentors are going to be a great resource for the community. We’re excited to work with them to help roll out our LID programs in the city,” Boehme said.

Master Gardener Program Coordinator, Laurel Moulton, is excited about the win-win nature of the program. “With the extreme budget cuts we’ve had, this program has potential to fill gaps and help the city, the county, and the Clallam Conservation District address this serious water pollution problem,” she said.

With Rain Garden Mentors providing education, Clallam County is prepared to consider rain gardens as an alternative to downspout drywells (underground pits filled with gravel) which are standard for new construction in the county. County engineer Ross Tyler is also hopeful about the program. “Rain gardens are much more efficient in terms of mitigating both the quantity and quality of stormwater runoff.”

Hands-on Design and Build

The WSU Rain Garden Mentor Program teaches Master Gardeners volunteers how to assess a potential garden site and design a rain garden. Trainees gain hands-on experience while installing rain gardens, and they learn about incentive and grant programs which they then help homeowners access.

Rain Garden Mentor volunteer, Doug Ridgeway, is a retired California flood control construction manager who had never considered anything like a rain garden before. “I now see them as a very effective way of dealing with stormwater,” Ridgeway said. He also sees rain garden construction as an economic opportunity for small contractors and is happy sharing his knowledge of rain gardens with people in Clallam County.

12,000 Rain Gardens

The WSU Extension Rain Garden Mentor program in Clallam County is part of the 12,000 Rain Gardens Campaign which aims to install 12,000 rain gardens in 12 counties surrounding Puget Sound by 2016–a charge headed up by WSU Extension and the nonprofit Stewardship Partners.

WSU Master Gardeners have long emphasized water quality protection through gardening practices like reducing pesticide and fertilizer use, composting, mulching, and using groundcovers to reduce erosion. Now homeowners in western Washington communities have another tool to help them garden as an act of stewardship.

The WSU Rain Garden Mentor program in Clallam County is the result of a unique partnership between WSU Extension, the Clallam Conservation District, the City of Port Angeles, and Clallam County. Learn more at www.raingarden.wsu.eduor contact Laurel Moulton at lmoulton@co.clallam.wa.us.

-Sylvia Kantor

Alternatives to Polyethylene Plastic Mulch Explored in New WSU Extension Publication

“Using Biodegradable Plastics as Agricultural Mulches”
“Using Biodegradable Plastics as Agricultural Mulches”

Widely used for crop production worldwide, polyethylene plastic mulch controls weeds, conserves soil moisture, increases soil temperature, increases crop yield and quality, has a relatively low cost, and is readily available.

But the use of polyethylene mulch raises many concerns. Polyethylene mulch is manufactured from non-renewable, petroleum-based feedstock, is neither biodegradable nor recyclable, and typically has an operational life of only one growing season before it gets thrown away. In 2004 alone, 143,000 tons of plastic mulch was thrown away in the U.S., either in landfills or burned on site. This amount of plastic mulch, typically measuring four feet wide and 1 mil thick, would wrap around the earth over 100 times.

Biodegradable plastic products are more desirable because they can reduce non-recyclable waste, conserve resources, and decrease environmental pollution. In agriculture, biodegradable plastic mulches offer an alternative to polyethylene mulch production and disposal.

Organic farmers in the U.S. are not able to use currently available biodegradable plastic mulch products because they do not conform to current NOP standards. Currently, certified organic farmers are allowed to use polyethylene mulch if it is removed at the end of the growing season. To some people, such use represents a contradiction between the resource conservation goals of sustainable, organic agriculture, and the waste generated from the use of polyethylene mulch.

“Using Biodegradable Plastics as Agricultural Mulches” explains how biodegradable plastic mulches are made, what constitutes biodegradability, and the advantages and disadvantages of plastic mulch in general. This WSU Extension publication is also useful in informing the conversation between agricultural professionals, farmers, and policy makers about the current research on biodegradable plastic mulches for agricultural uses.

“Using Biodegradable Plastics as Agricultural Mulches” is available as a free PDF download at http://bit.ly/biodmulch.

Teaching the Teachers: Environmental Education Is Focus of March 30 Workshop

Washington State University Extension will offer Project Learning Tree Training for teachers and informal educators 9:00 a.m.-3:30 p.m., March 30, at the Snohomish County Extension office, 600 128th St. SE, Everett.

The workshop will use the acclaimed Project Learning Tree curriculum to give participants access to hundreds of simple activities for integrating environmental education into a classroom, club, or after-school program. Activities address Washington’s four Essential Academic Learning Requirements for science, with an emphasis on experiential learning and getting kids outside to explore science and nature.

The training costs $45, and includes the Project Learning Tree Environmental Education Activity Guide, lunch, and six clock hours of instruction. Registration information is available at http://bit.ly/156vXpW or 425-357-6023. Information on a second workshop, to be offered May 18, is available at 425-357-6023.