It isn't Waste if You Do It Right

A few days ago, the New York Times ran an article about the problem of manure handling on large farms. . From the title "Down on the Farm, an Endless Cycle of Waste," which completely misses the point that manure is not "waste" to the end, the article failed to ask any of the really pertinent questions raised by really large scale industrial agriculture and its chronic problems with manure handling.

In function it is something like a Zamboni, but one that has crossed over to the dark side. This is no hockey rink, and it's not loose ice being scraped up. It's cow manure.

Lots of cow manure. A typical lactating Holstein produces about 150 pounds of waste -- by weight, about two-thirds wet feces, one-third urine -- each day. Mr. Volleman has 3,000 lactating Holsteins and another 1,000 that are temporarily "dry." Do the math: his Wildcat Dairy produces about 200 million pounds of manure every year.

Proper handling of this material is one of the most important tasks faced by a dairy operator, or by a cattle feedlot owner, hog producer or other farmer with large numbers of livestock. Manure has to be handled in an environmentally acceptable way and at an acceptable cost. In most cases, that means using it, fresh or composted, as fertilizer. "It's a great resource, if used properly," said Saqib Mukhtar, an associate professor of biological and agricultural engineering at Texas A & M University and an expert on what is politely called manure management.

But as the increasing incidence of environmental and health problems linked to agriculture makes clear, when manure is mismanaged the nutrients in it can foul streams, lakes and aquifers; the pathogens in it can contaminate food products; and the gases it produces, including ammonia, methane and bad-smelling volatile compounds, can upset neighbors and pollute the atmosphere.

Even with best practices, manure can cause environmental headaches. So researchers are working on ways to improve its handling, to modify the nutrients in it and to develop alternative uses.

I'm so glad we have researchers working day and night to figure out how to manage 200 million lbs of cow manure, to make it less toxic, and to deal with the environmental "headaches" that even the "best practices" can cause. If it were me, not being a researcher, I would tend to think that those research dollars could be spent elsewhere, maybe on breeding a cow with antennae or something really cool, because I know the magic trick to making manure not an a massive environmental hazard that is risky even with the "best practices." After extensive research (and I'd really like some company to pay me some money for this, since I obviously worked hard at figuring it out, and am clearly a genius), I've figured out how to reduce the manure handling hazard, and convert it from "waste" to something extremely wonderful and useful (although I can't make it smell like lavender."

Don't have 4,000 cow dairies. Don't put more cows in one place that make since given the land's capacity to absorb the manure. Don't set up a system that needs a manure lagoon and a shit-scraping zamboni running 24 hours a day. Don't have so many cows that manure functions as "waste" because it isn't - it is fertilizer. But it is only a fertilizer if you can return it to local land - as the article points out, it doesn't make sense to truck manures long distances - and that means a smaller number of cows in more dairies.

But the Times article doesn't consider this. The assumption is that the manure lagoons and the practices that surround that kind of quantity of manure are inevitable:

With nitrogen, the problem is usually not that there is too much, but that much of it is eventually lost from the manure in the form of gaseous ammonia. The bacteria in feces contain an enzyme, urease, that breaks down urea in urine into carbon dioxide and ammonia. As with phosphorous, diet can affect the amount of nitrogen retained in the manure. As corn-based ethanol production has increased in the United States, many dairies and feedlots now give their animals a large amount of so-called distillers' grains, the waste corn after fermentation, which are plentiful and cheap. A recent study of feedlots in the Texas Panhandle, by scientists with the United States Department of Agriculture, showed that feeding a diet high in distillers' grains produced significantly higher ammonia emissions from the manure.

Emissions problems can also be reduced by changing how the manure is applied. Tilling the soil immediately after application of dried manure can help reduce odors, Dr. Mukhtar said. And if manure is directly injected into the soil in slurry form, Dr. Burns said, the ammonia can better bind with the soil. Currently in Iowa, a major hog-producing state, about 80 percent of hog manure is injected.

When it comes to the liquid end of things, there are delicate balances to be maintained as well.

Regulations vary by state, but in Texas, manure lagoons have to be big enough to handle a severe rainstorm of the type that occurs, on average, only once every quarter-century. The danger is that an overflow from a lagoon, with its high concentration of organic matter and nutrients, could eventually reach a creek or some other body of water and kill fish.

Ok, in Texas, you have to be big enough to handl the 25 year storm. But wait a minute. What happens when the 50 year storm happens? Or the 100 year storm? Or for that matter, what happens when climate change ups the rate of those storms?

Even without those storms, we have ample research to suggest that manure lagoons are not the hottest idea on the planet. For example, not all areas that have lagoons should have them - when groundwater runs near them, you get contamination anyway There have been more than 200 significant manure spills and leaks from lagoons in just the last four years, many with substantial environmental costs, including one in New York in 2005 about an hour from me that killed 375,000 fish in the Black River and contaminated local water tables.

The truth is that this much animal manure cannot be handled safely over the long term - all of our best attempts to regulate and control have not stopped CAFO animal manures from contaminating water tables, rivers, lakes and streams. Moreover, if you imagine that we don't have all the fossil fuels we could ever want, or that we shouldn't burn them these agricultural models are a complete disaster. Putting 4 or 5 or 6 thousand cows in one place means that the farm will always be profoundly dependent on energy intensive equipment like the manure-zamboni. They will always be overwhelmed by the fact that their land can't absorb all the manure. A single shortage or extended outage is a disaster.

And we can't afford to waste our manures. The article above cheerfully reports you can reduce odor by tilling the manure in - but of course, besides being resource intensive, this means that carbon held by the soil is being released, rather than contained. We need to reduce tillage, not increase it, or begin it on pastures and hayfields, which are environmentally positive in large part because they are not being tilled. Besides producing a shitload (forgive me) of methane, they are also upping carbon release this way.

We also can't afford to waste our manures because we need the fertilizers. We have already seen wild fluctuations in fertilizer costs in the last few years, resulting in farmers struggling to afford to buy enough. Potash prices rose dramatically in 2008-2009, while the cost of artificial nitrogen and rock phosphates have also fluctuated. Farmers can't afford to ignore local resources. But, as the article points out, it doesn't make sense to truck manure more than 10 miles.

But again, that's the magic of my solution. Instead of 1 4,000 cow dairy, let's say you have 40 100 cow dairies. Guess what? They can't all exist on exactly the same land - so you spread that manure out. Most farms that raise their cows on pasture can pretty much handle the manure produced by 100 cows, assuming they have agricultural neighbors to share with. Better yet, what about 100 40 cow dairies? Your average farm that can support 40 cows can completely handle their manure. No lagoons, just composting piles and spreading on fields - and a lot fewer piles, because, of course, if the cows actually go outside and eat grass, they are spreading their own manure.

In my own region of the country, thousands of dairy farms have gone out of business. Did those farmers just hate their work and voluntarily give up the ghost? Nope - I know these guys and they are my neighbors. My town had twice as many dairies 10 years ago, and twice as many as that 20 years ago. It has been a long and painful process of agonizing attrition, farmers hanging on just one more year, trying to make it work as they are undercut by people with 4,000 cows and with an agricultural system that would rather invest money in research to make the poop less toxic than simply recognize that none of us are served by the consolidation of dairy farming. It would haven't taken a massive shift in subsidies and practices to keep those guys in business, and I know 10 who would go back in a heartbeat, if they could be promised something other than another disaster. These are guys who love their cows, who know their 60 cows, who wanted nothing more than to keep getting up at 4 in the morning for the rest of their lives so that you could drink a glass of milk.

Sharon