Biochar: Miracle or Gimmick?

Biochar-and-Pyrolysis_1

Cornell University illustration showing biochar as a means of sequestering greenhouse gases.

I’m always skeptical of what I call the “notions and potions” school of gardening. Every few years there is some new substance touted as the secret to a lush vegetable garden. One such substance is biochar, a kind of charcoal used as a soil amendment.

The University of Minnesota Extension service is in the midst of a four year study to test the use of biochar in vegetable gardens.

Preliminary results (which you can read here) show benefit for some crops such as kale, but a decrease in growth for others such as asparagus.

The more we learn about biochar, the more we need to learn. From an overall standpoint, there appeared to be some benefit of using biochar in the nutrient-depleted sandy soils at the Andover site for some crops. Yet, there was a decrease in growth in some plants and higher yield in others. In the Arboretum and St. Paul campus sites, we noted similar results, but more crops seemed to decline with biochar than without it.

There’s nothing new about biochar. It was in use by native peoples in the Amazon region before Columbus. Hopefully this study will help clarify what types of soils and what crops benefit most from its use.

Do you have an opinion about Biochar? Leave a comment . . .

And thanks to Michael Tortorello for sending me the link.

Straw Bale Garden Part IV: Almost Ready to Plant?

straw bale garden

Over the past fifteen days I’ve been “conditioning” my straw bale garden by adding blood meal and a lot of water. During the conditioning process we had both a freak rainstorm (helpful) and a freak heatwave (not so good).

The bales did not heat up as much as I expected–as of this morning they are around 80° F, around 15° to 20° higher than the ambient temperature. Several sources I checked, however, suggest that this is hot enough. The test will be when I plant seedlings. If they end up stunted, I’ll know that I did not let the bales compost long enough.

One problem I had with the conditioning process is that the straw on most of my bales was oriented with the stem sides facing the wide (vertical) side of the bale. This made it difficult to get the blood meal into the bales. One or two of the bales had the straw oriented with the stems facing up and these bales seemed to heat up faster.

Another problem was keeping the bales moist in our hot and dry climate. Tarps may have helped.

The next step will be to plant seedlings and add a balanced fertilizer (fish emulsion) every other week.

Compost and Pharmaceuticals

happypills

We get this question a lot–will pharmaceuticals end up in my compost if I use human urine or animal manure? This is really three questions:

  • Does composting break down pharmaceuticals?
  • Are some pharmaceuticals worse than others in terms of their ability to survive the composting process?
  • If pharmaceuticals persist after composting do edible plants uptake them in sufficient quantities to effect humans?

A look at what science has to say
We really need a Root Simple research department! I was able to find a few studies that, at least partially, address these questions. If you know of more please leave a link in the comments.

A 2010 study looked at the degradation of salinomycin, used on chickens to prevent coccidiosis. The study concluded,

On the basis of the results obtained in this study, it appears that the composting technique is effective in reducing salinomycin in manure.

Another 2010 study looked at the composting of sewage sludge containing fluoroquinolones (broad spectrum antibiotics),

The concentrations of pharmaceutical residues in compost were significantly lower, if compared to the relevant concentrations in sewage sludge . . . It is concluded that before using the sewage sludge compost as a fertilizer it should be carefully tested against the content of different pharmaceuticals. The content of pharmaceuticals in the compost made from sewage sludge may easily lead to the elevated concentrations in food plants, if the compost is used as a fertilizer.

A slightly contradictory Estonian study concluded:

In the current study, uptake of ciprofloxacin, norfloxacin, ofloxacin, sulfadimethoxine and sulfamethoxazole was demonstrated in lettuce. The uptake of fluoroquinolones and sulfonamides by plants like lettuce does not seem to be a major human health risk, as the detected levels of the studied pharmaceuticals were relatively low, if compared to their soil concentrations. Further studies are needed to determine the uptake of different types of pharmaceuticals and other organic pollutants by various crop plants.

What about hormones? A paper in the Journal of Environmental Quality concludes,

composting may be an environmentally friendly technology suitable for reducing, but not eliminating, the concentrations of these endocrine disrupting hormones at concentrated animal operation facilities.

But we’ve got a lot of hormones making their way into the environment due to agriculture, according to a study done by Temple University,

Animal manures (poultry manure and cow manure) contribute to a significant load of estrogen hormones in the natural environment.

Conclusions
Clearly we may have some big societal problems caused by the overuse of pharmaceuticals and waste generated by industrial livestock operations. Those issues are beyond the scope of this blog.

But what about home composting? Should I pee on my compost pile if I’m on lots of pills? Maybe not. But I think there are a few common sense guidelines we can follow when working with human and animal urine or manure at home:

  • Don’t use municipal compost that is made with sewage sludge, though I’m more worried about heavy metals in that compost more than I am about pharmaceuticals.
  • Since I’m not on any pharmaceuticals, I’m not worried about my own urine in the compost pile.
  • Joel, who commented on an earlier Root Simple post about using urine in compost, had this to say, “The main thing I’d worry about is radionuclide therapy, such as treatment with radioactive iodine vs. thyroid cancer. I guess I’d also worry a little about people who are on chelation therapy to flush toxic heavy metals from their system. If it’s not concentrated enough to harm your kidneys, though, I’m thinking it’s not enough to worry about in soil…perhaps that is me being naive.”
  • If I were collecting pee soaked straw bales at a French heavy metal concert (unlikely!),  I might have the resulting compost tested if I were going to use it on vegetables. But composting those bales would be better than flushing all that urine down the sewer system.

As to the bigger environmental issues, the good news is that some of the research shows that composting can help reduce pollution. And, since some of us have the space to compost at home, we can all contribute to a cleaner planet.

What do you think? Leave a comment . . .

Straw Bale Garden Part III: Adding Fertilizer

watering fertilizer into a straw bale garden

After watering our straw bales for three days our next step is to apply a high nitrogen fertilizer. We’re following West Virginia University Extension Service’s Straw Bale Gardening advice. They suggest a 1/2 cup of urea per bale or “bone meal, fish meal, or compost for a more organic approach.” (I think they mean blood meal as bone meal does not have much nitrogen in it.)

Choosing the organic approach, we’re watering in two cups of blood meal a day to each bale for days four to six. Days seven through nine, we’ll cut back to one cup of blood meal per bale. By day ten the bales should be almost ready to plant.

Once the bales are conditioned I’ll need to add a balanced organic fertilizer to provide potassium and phosphorous. And I discovered that taking the time to level the bales prevents fertilizer from running off when you’re trying to water it in.

Fertilizer Issues
Buying a high nitrogen fertilizer, even an organic one, is a bit of a conundrum. I object to chemical fertilizers, like urea, on philosophical grounds, but blood meal, a byproduct of our industrial food system, doesn’t make me feel much better. Urea would be a lot cheaper.

Perhaps the best solution would be human urine. Throw a week-long party, serve a lot of beer and invite your guests to fertilize your bales! Undiluted human urine has an NPK ratio close to that of blood meal.

Those of you who have experimented with straw bale gardens please leave a comment on what fertilizers you used and how it worked . . .

A Straw Bale Urinal

straw bale urinal

L’Uritonnoir, a plug-in straw-bale urinal. Photograph: Faltazi

At the risk of becoming a blog entirely about urine and straw bales, Anne Hars alerted me to an article in the Guardian, “L’Uritonnoir: the straw bale urinal that makes compost from ‘liquid gold’” about French design studio Faltazi’s plug-in straw bale urinal.

The device comes as a flat polypropylene sheet, which is folded into shape and slotted together, then threaded on a looping band around the bale, its funnel wedged deep into the centre of the straw to channel the fluid to the composting core. A deluxe version is also available in stainless steel – presumably for the VIP bale urinal area.

L'uritonnoir by faltazi

According to the article, Faltazi’s straw bale urinal will debut this summer at the French heavy metal festival Hellfest.

Ladies will have to pack their funnels.

Lady Urine, Water Conservation and Halfway Humanure

red auto store funnel/ pee cup for ladies?

I approve of the oval shape of the opening of this funnel– and the sporty color.

Fact 1: Human urine is an excellent source of nitrogen for your garden. It can be applied directly to a compost pile, or diluted 10:1 and used on plants.

Fact 2: Nature has equipped the male of the species in such a manner that it is easy for him to contribute nitrogen to the compost pile. For women, it’s a bit more tricky.

So, how do ladies give back to the soil?

Yesterday we had a comment from an anonymous female reader, telling us how she adds urine to her compost pile. She uses an inexpensive funnel from an auto-supply store. (Auto parts for lady parts?)

funnel

This funnel has a handle, which is convenient. But I’m not sure how to interpret the look of the thing. It’s sort of disturbingly medical-techno.

The advantage of this type of funnel over, say, a kitchen funnel,  is that it has a very long nose or nozzle. This, she explained, allows her to neatly direct the urine into a watering can. Very smart.

I wondered if other female readers out there had tried-and-true methods for urine collection that they’d be willing to share? I’m terrible at it, myself.

This is particularly pertinent for Erik and I right now because, as regular readers know, we’re trying out this strawbale garden thing. We can help to get the bales going by peeing on them.

But there’s a lot of bales, and Erik only has so much pee. My contributions would be useful. Plus, this method of gardening is undeniably water hungry. I feel like we should partially offset this expenditure by conserving water as much as we can.

One simple way to save water is to stop flushing the toilet so much. And if all our pee went outside, it would not only save water, but it also would add water and nitrogen to the soil. Win-win.

Now, I imagine our more feisty readers will ask, why stop at pee? We’re big supporters of the humanure concept and have kept a dry toilet in the past. It’s not difficult to compost human waste , but you  do have to be careful, and you need a dedicated humanure pile–more than one, really. More like three. We just don’t have room for that right now.

But there’s a compromise solution. I call it Halfway Humanure. It’s easy to institute a urine-only dry toilet in your home or yard.

dry toilet

Our milk crate toilet.

That means you get yourself a five gallon bucket and one of those camping toilet seats which snaps onto a five gallon bucket. Or you build yourself a deluxe model, like ours. You put a nice cushion of  sawdust or wood shavings or crushed dried leaves or whatever works for you at the bottom of the bucket (maybe 3-4″) and start using it. Top it off with a sprinkle of dry stuff each time you use it. Keep the lid closed. It will not stink.

Reserve #2 for the flush toilet. This keeps things simple. If you’re only collecting urine, you don’t have to be a talented composter. And for the flush-toilet trained, it’s much easier to pee in a bucket than to poop in a bucket. It’s just not such a big psychological leap. (It’s actually a great stepping stone to full humanure composting, if that’s your goal).

The material you collect can go straight onto your regular compost pile–no special treatment required–and it’s a valuable resource.

So, to sum up this meandering post, while Erik is “watering” the straw bales, I think I’m going to be collecting my nitrogen inputs in the dry toilet. (That it, unless I trot myself down to the AutoZone and get myself a funnel.) Both of us, in our different ways, will be contributing to the fertility of our garden.

Straw Bale Garden Part II: Watering the Bales

straw bale garden--watering the bales

In case you just joined us, we’re starting up a straw bale garden. I’ve decided to go with instructions provided by Washington State University. The first step is to wet the bales. Here’s what WSU suggests:

To start the process, keep the straw bales wet for three to four weeks before planting. If you would like to speed up the process, here is a recipe that works well.

Days 1 to 3: Water the bales thoroughly and keep them damp.
Days 4 to 6: Sprinkle each bale with ½ cup urea (46-0-0) and water well into bales. You can substitute bone meal, fish meal, or compost for a more organic approach.
Days 7 to 9: Cut back to ¼ cup urea or substitute per bale per day and continue to water well.
Day 10: No more fertilizer is needed, but continue to keep bales damp.
Day 11: Stick your hand into the bales to see if they are still warm. If they have cooled to less than your body heat, you may safely begin planting after all danger of frost has passed.

To make sure I keep the bales wet I’ve also installed soaker lines on a timer.

My straw bale garden is more water intensive than I would like, but I try not to let perfection be the enemy of the good. In the end the compost I make will help conserve water in the garden–at least that’s my theory.

Next step will be to add fertilizer in the form of blood meal (I’m puzzled by WSU’s suggestion of bone meal). More on that subject in three days.

Our New Straw Bale Garden–Part I

straw bale garden

Straw bales–ready to prepare. Pot in the center will be a solar powered fountain.

We’re going to experiment with a straw bale vegetable garden in our backyard, inspired by Michael Tortorello’s article in the New York Times.

The plan is to grow in the bales and harvest the resulting compost for use in permanent raised beds (that have yet to be built). We’ll keep growing in bales until we have enough compost for the beds.

The problems presented by our property–lead and zinc contamination and a backyard that is up 30 steps–make straw bale gardening a promising solution.

  • Bales and fertilizer are easier to carry up the stairs than bulk soil.
  • It will be cheaper than buying soil.
  • No lead and zinc.

I was also inspired by this attractive straw bale garden in Arizona.

It will be a garden that changes over time. I like the idea of watching the bales turn into compost and their gradual replacement with more permanent structures. I’m hoping that the view from the two Adirondack chairs that face the bales will be like a botanical Robert Smithson piece–a front seat on nature’s balance of entropy and creation.

The next step is to add fertilizer and water. We’ll document what happens so stay tuned.

Our Keyhole Vegetable Bed: What Worked and What Didn’t Work

keyhole garden bed

This is what our keyhole bed looked like yesterday just before I fed the remaining vegetables to our chickens and the compost pile. Ignore the large pot–that’s a future solar powered fountain that will be incorporated in a new vegetable garden we’re working on.

keyholebedoctober

Here’s what the keyhole bed looked like just after I installed it back in October. Note the compost repository in the center of the bed. I used straw wattle (available where professional irrigation supplies are sold) to form the sides of the keyhole.

keyholedecember

A month later in November a few seedlings were popping up. I had to robustify the skunk barrier (made out of bird netting) after repeated skunk raids.

What worked:

  • The compost decomposed nicely and seemed to attract insect life.
  • Stuff grew.

What didn’t work:

  • I didn’t make the bed high enough–more height may have helped prevent skunk incursions.
  • The compost bin in the center of the bed should have been sturdier. Skunks got into it eventually.
  • The cheap bagged soil I bought had a lot of wood chips in it. Brassicas did fine but other veggies did not appreciate the high carbon content of the bagged soil. It would have been better to make my own soil with high quality compost, but I was in a hurry.
clover

Clover in the keyhole bed did well and produced some pretty spring flowers.

Conclusions
Despite my mistakes, I heartily endorse the keyhole bed concept. I’d just make the sides higher and take more time putting the bed together. My neighbor Anne Hars layed her keyhole bed out more carefully and, as a result, it was more productive and more aesthetically pleasing. Part of the problem for us is that the keyhole shape, from a design perspective, didn’t work in the space we put it in. We’ll blog about the new veggie garden we’re putting together where the keyhole bed used to be in future blog posts.