Biosolids, soil health key topics at 103rd annual Lind Field Day

The 103rd edition of Washington State University's Lind Field Day took place at the Lind Dryland Research Station on June 13, as WSU and United States Department of Agriculture researchers shared updates on a number of different topics to regional farmers and industry stakeholders.

Topics of interest at this year's Lind Field Day-which WSU says is the best-attended annual field day they host across the region each year-included field sessions on spring and winter wheat breeding, winter peas, biosolids and soil health assessments.

Winter peas

Rebecca McGee, a research geneticist for USDA, and Howard Nelson from HighLine Grain Growers provided updates and gave a general outlook on the winter peas market. Nelson said that peas are an exciting new crop for farmers located in low to intermediate rainfall areas.

"The reason I say that is because it's a crop we can add to our cropping system. And so when we talk about cropping systems here in the dry areas, basically most guys are talking about whether you're conventional seeding or direct seeding, because it's kind of assumed that wheat is your crop," explained Nelson.

Peas, Nelson says, gives dryland farmers the chance to grow a crop that's different than wheat. Peas give the ground a chance to reduce some of the soil-borne pathogens that may be affecting the wheat, and gives farmers a chance to use different crop sizes that they otherwise wouldn't use.

Nelson also pointed out that peas are part of the legume family, which means they make their own nitrogen, saving growers the hassle of applying nitrogen to their pea crops. "You can actually lower the amount of nitrogen to apply to crops following [the pea crops]. It's kind of a unique thing," Nelson said.

Another enticing benefit of growing winter peas is that research has shown as much as a 30% yield increase in winter wheat following peas. Nelson said that in wheat fields that were following peas, wheat has a much darker green color compared to fallow.

Peas grow very well in the area, and have developed rapidly in just the roughly 20 years they've been bred at the Lind Dryland Research Station.

Market-wise, peas are both exported and used domestically. India is the No. 1 customer in the export market and there is currently a 55% tariff on peas going into the country, which Nelson says has reduced the market dramatically. China is the No. 2 export market, which currently has a 25% tariff on peas going into the country as a result of an ongoing trade dispute. "The export market has really suffered this past year," Nelson said.

In good news, the domestic market has continued to grow, almost doubling in the last three years. The growth has come in peas being used in pet food and as fractionated pea protein in products such as the Impossible Burger and the Beyond Burger.

Biosolids

WSU's Bill Schillinger and USDA's Tim Paulitz presented about recent developments in biosolids and shared the results of recent research at the Dryland Research Station when using biosolids as a fertilizer compared to synthetic fertilizer.

Over the past seven years at the station, the average wheat yield was identical when using biosolids compared to synthetic fertilizer, reported Schillinger. The yearly average is 49 bushels per acre over that span, which included two very dry years in 2014 and 2015, when the yield dropped to as low as just 21 bushels per acre.

One of the big differences in the wheat when using biosolids compared to synthetic fertilizer is the straw weight. "We are producing way, way more straw with biosolids than we are with synthetics. I don't know if it has to do with all of the micronutrients and more heads per unit area, or what have you," said Schillinger.

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While Schillinger presented data on how biosolids affect wheat agronomy, Paulitz presented research about how biosolids might affect the soil microbes.

The questions they wanted to ask in terms of determining the impact of biosolids on the soil microbes were: what microorganisms were being brought in with the biosolids, such as pathogens; and whether microbes are using biosolids as a food source, due to the large amount of carbon and nitrogen in the biosolids.

Paulitz presented a summary of his findings, which concluded that they could detect organisms that were brought in by the biosolids. Additionally, the biosolids serve as a great food source for fungi and bacteria.

Schillinger said that Class A Biosolids are growing in demand. Class A Biosolids are dewatered and heated sewage sludge that meets the Environmental Protection Agency's guidelines for land applications with zero restrictions, making them available to use as fertilizer on areas such as farms, vegetable gardens and home gardeners.

Schillinger explained that every municipality produces sewage sludge. The municipalities can either burn it, put in the dump or use it. Most of the municipalities, Schillinger says, are deciding to use it. "Intuitively, some people don't like the idea of putting Seattle sewage sludge out here on our farms."

Soil health

One of the more interesting presentations of the day came from Dr. Shannon Cappellazzi, a project scientist for the Soil Health Institute in North Carolina. Cappellazzi was focused on explaining how soil health assessments could be useful for farmers.

Cappellazzi has been working with WSU professors to sample their long-term research sites as part of the North American Project to Evaluate Soil Health Measurements, which samples 31 indicators of soil health across roughly 120 long-term sites in the United States, Canada and Mexico.

Cappellazzi kicked off her presentation by simply asking the audience what soil health was. Soil health, Cappellazzi defined, is "the continued capacity of the soil to function as a vital, living ecosystem within ecosystem boundaries" Soil plays a key role in the lives of growers, as it: grows plants; stores, filters and delivers water; stores, delivers and cycles nutrients internally; provide resistance to weather events; and provides a habitat for microbes.

The microbes in the soil, Cappellazzi explains, are each doing a different job to create a habitat for themselves. The habitats, just like those used by humans, provide food, water, air and shelter for the microbes.

Going back to the initial definition she gave, Cappellazzi explained why it's important for farmers and growers to care about the soil's continued capacity to function. "As producers, I would say one of the biggest things you have to care about is being able to plant your crop the next year. You have to be economically sustainable in order for you to continue your job and in order for you to give your family the food, the water and the shelter they need, right?"

"The reason that we are focused on how the soil functions is because if we can get the soil to do some of these functions for us, we can reduce our input costs," Cappellazzi continued. "If we can reduce the amount of fertilizer that we're using ... then we can decrease our cost of our input, thereby increasing our profits."

In Adams County and eastern Washington, Cappellazzi noted that one of the biggest issues is probably the ability to store and deliver water. If they can increase the soil's ability to hold water and make more of that water available to plant, it will be better for the growers' bottom lines. In a dryland system, she said, "everything is going to come down to whether or not you have enough water to grow your crops."

At the Soil Health Institute, one of their overarching goals is to enhance the practices that allow producers to have better water retention, higher nutrient cycling and a higher diversity, which allows for a broader functional diversity in the soil. Doing this should, at the end of the day, help farmers grow crops.