Questions about Biochar

I was really gung-ho to start making some biochar and then I started watching Youtube videos and am now thinking about scrapping the entire plan. The reason is, I have all kinds of wood that I could convert to biochar, but then in reading up on it, it says that biochar is only 5% of a good compost mix. This really knocks the wool off my sheep because I have plenty of biochar I could make, but a limited supply or compost (sheep manure). It also makes me wonder if biochar is really good as everyone says it could be as it seems to me that putting down that much compost is what is making the soil so vibrant and probably has very little to do with biochar itself. Twenty five years of manure applications have proven what organic matter can do for a farm like mine.

Sadly they say a person needs 15 tons of biochar to the acre ideally. In doing the math, that is a whopping 13 cords of wood per acre, and to do just the fields of my farm I would need 1600 cords of wood. Yeah you read that right, 1,600 cords!! With 1280 cords, I could burn the wood down to ash instead of charcoal, spread that upon my fields and get the ideal PH levels, as well as phosphorous and potassium ratios. With either method I would need to use sheep manure to get my nitrogen levels right.

The last question is, how would I incorporate that many tons into my soil? Tilling would be the only answer I would think. If I top dressed the grass ground, at a recommended spreading rate of 1 ton per acre per year, it would take me 13 years to get to where I need to be. That is a bit too long.

Does this make sense or am I missing something?

I have seen tests where people used anywhere from a couple percent, up to 30% biochar in mixes.  Personally, I wouldn't even try to use biochar on the scale you are dealing with, but if I were to try it large scale, I would till it in and go back to no-till once it was incorporated.

That's a huge amount of wood! Do you have a garden? I myself would focus on biocharring just the garden instead of the farm in its entirety, unless you really think the soil needs it for improved pasture. And instead of tilling it in the garden, broadcast it on the surface and cover with mulch. Bugs and worms will do the tilling for you.

I've been making biochar for only a couple of years and I'm only doing it on a small-ish scale.  I use all of the stuff that's too small to put in the wood stove (anything under 2 inches in diameter and too short to mess with stacking). Last year I made something like 500 gallons of biochar for my veggie garden using a trench method that I saw demonstrated by the guy from the youtube channel skillcult  SkillCult Youtube Channel

It was good use of the materials I had on hand.   In the garden beds with the biochar, I did have better results with water retention and growth.  I'm planning to do the same tihng again this winter.  

I also save all of the ash from the wood stove to use in the garden as well.  The soil here is a little on the acidic side.  

The best tomatoes and peppers I've ever grown came from the place where I added a lot of biochar.

It's a bit of work, but I think it works out well over the long haul.  If you're already cutting wood for timber or cord wood, I'd say that it would be worth it to save the slash and use it for biochar.  

I actually made a little charcoal today. It was raining out, a Sunday, and what better thing to do then start a bon fire and chunk in some wood?

In the end I kept my experiment smaller than I originally wanted, I built my charcoal pit big enough to hold 4 cord, but ended up only burning 2 cord. I used 50/50 Red Spruce and White Pine just because I had a ton of it kicking around. The fire burned hotter and faster than I expected, so I was busy chunking up wood and tossing it in as fast as it burnt down. When it was really burning I brought in my bulldozer and covered the pile with soil to snuff out the flames. I am hoping with soil over it the pile will retain its heat, continue to char and net me more charcoal from the wood. Sadly my wood was pretty big; tops of trees that did not make the grade for logs. I grabbed my smallest ones, but they still were 8-18 inches in diameter.

So far I am pretty happy with the process. The time constraints have not been that bad, so really it is just a matter of a couple of things.  First, how much volume 2 cords of wood nets me. I figure I will get around 3/4 of a cord of charcoal. That is assuming a 50% conversion rate, and then some losses from getting it out from under the soil. The second thing is, how the quality will be. I think I will see how this batch burns in my wood stove.  

Anyway, this is how it breaks down time wise:

30 Minutes to dig the hole
2 Hours to cut the wood
2 Hours to burn the wood
15 minutes to cover the pile (2:45)

That is comparable to producing 3/4 of a cord of firewood, felled, limbed, hauled out, bucked and split. Both need/would need to be moved to the woodshed/collier shed.

travis, my only concern is with that based on prior posts you have high OM and biochar will likely add to that. I use it to increase my OM and artificially increase my CEC. It sounds like that is not your battle, although keeping your calcium around may be beneficial and save some money! I will be interested in your success.

You are a mad scientist and that is inherently good for the rest of us!

My plan now is to burn it in my wood stove. I have a pot bellied stove so coal burns in it better than wood simply because it has such a small firebox. For me this is good because my home is super insulated. I love burning coal, but unfortunately I have a lot of firewood here in Maine, but not a seam of coal otherwise we would be having a much different conversation! So making my own homemade coal has interest.

But you are right, Biochar has little benefit on my farm. Aside from the organic matter being above optimum, so too is iron, copper and Zinc, something biochar is high in. Since my PH is already pretty good thanks to some lime this year, it means its not a PH imbalance artificially inflating the micro-nutrient numbers, but overdoses of iron, zinc and copper!

I thought about selling it, and I have not ruled that out yet, but the idea of converting softwood that has no commercial value to that of heating my home has interest for me.

Travis Johnson wrote:

I thought about selling it, and I have not ruled that out yet, but the idea of converting softwood that has no commercial value to that of heating my home has interest for me.

I think you could do big business in that, at least around here. Selling inoculated biochar, yeah you could move a lot of that! I just did a craiglist search and no one is selling it around here. That is genius!

hau Travis,

It is good to see that you did some of the math concerning biochar.  Having done some biochar on my farm I'd love to give you some of my findings from that experiment, do with them what you like.

Biochar does work on several levels, but biochar is not charcoal put into the ground. Biochar stands for Biologically active charcoal, this means that there are many microorganisms already living in and on the charcoal before it is incorporated into the soil.

Biochar does not work well when simply spread on the surface, it does work best if it has been placed at least 3 inches below the surface, that means you have to dig it in somehow (disking in seems to be the best method for large farm plots (fields).
The placement of the biochar indicates that it is best used at the time you are doing the one disturbance that allows you to get the soil going in the direction you want it to go, this should not be an every year, non-sustainable, method.

Use of biochar allows for immediate sequestering of lots of carbon (the charcoal), inoculation with a fairly complete microbiology (the biological portion that comes from inoculation of the charcoal either by composting it or soaking it in a compost tea), loosening of the soil via the extra humus (the charcoal) that will remain over time.

A field with biochar will perform certain functions for certain crops better than a field without biochar when bioactivity is the function tested for and most needed by the crop plants. (since all crop plants rely on the biology of the soil they grow in this means healthier plants which usually means better crop production)

Because of my experimental field, I am now incorporating biochar into other areas (the orchard is in progress) to increase the bioactivity levels for long term benefits. I only make additions once a year since it takes that long to get enough together to treat approx. 500 sq. yds. This amounts to right at 5 cords of wood and 40 gallons of compost tea to soak the char from the 5 cords of wood, I do wood burns of around 1 cord, soak the char then put this into a compost heap along with manures, straw and some green cuttings, by the time I have the quantity needed it is fully biologically active.

Trying to incorporate huge fields all in one year turns using biochar into a cost prohibitive measure and that makes it less likely to be utilized by large operations.

Redhawk