My opinion is that biochar is only likely to be beneficial to fruit trees if they are grown in nutrient-poor, deep sands or highly leached tropical soils. In sandy loam and heavier soils in temperate climates both clay and organic matter serve the purpose of retaining nutrients and water. Many posts here are about pruning and excessive vigor. Under those conditions one doesn’t want more nutrients and water. Maybe the best use would be to tie up nutrients. But that’s not what it’s used for.
I don’t water much, fertilize much, or prune much and yet have abundant crops of high quality fruit.
Just to clarify my planned field application is pretty specific and not intended to be applied to other approaches.
First, I’m working with rootmaker grown trees and planting them in clay soil. The advantage of planting these root pruned trees over bare root trees is that you the high density root ball is undisturbed and there is virtually no transplant shock. The down side to this is that water infiltration through the Promix medium I use in the containers. This causes two problems. First, in the spring when we get ample rain, water will pond in the promix and drown the tree. Second, if it survives that, the Promix will dry out much faster than clay and starve the tree of water. I have solved these issues with my planting method. First, I choose a planting site where ground water will not drain during heavy rain, a sight rise is best. Second, I use a tractor auger to dig a hole very close to the diameter of the container but I did it very deep. I use a hand rake to relieve any glazing. I amend the soil below the rootball but use native clay to fill and space around the root ball. During the spring, when plenty of water is available, it infiltrates the promix but pools well below the root ball. Since the hole is very close to the diameter of the root ball and the lateral roots are undisturbed. They quickly grow into the surrounding clay which retains more water during the summer. This method has been working well for me. Trees begin growing almost immediately. There is no sleep, creep, leap as with bare root trees.
My intent is to use the charged biochar as part of the amendment below the root ball. My hope is that as the tree grows it will be a source of microbial action and hold nutrients better.
Are you sure that what you made is biochar and not just ashes from the incompletely burned wood?.
My understanding is that biochar is produced without any FLAME actually burning /touching the wood being converted.
Basically biochar is what is left behind after wood is superheated without oxygen which causes some components of the wood ( water, sap etc.) to gasify and the gases are allowed to leave the chamber ( where they are used to then feed the fire that is outside the sealed chamber). As you noted … “I left one load burn too long and got almost all ash” and also that you soaked it to put it out. That would not be needed if no live flame actually engaged the target wood. After the proper “cooking time” , keep it closed and let it cool off inside the sealed oxygen free inner container.
I may have an incomplete understanding of how biochar is made but this is how I understand it is produced. No fire inside the cook chamber. The wood is not burned rather the water, sap etc. just gasify and the gas is vented out of the chamber. This leaves a greater volume behind almost the same as the original volume of the wood, it retains the shape but has more voids within the same outer volume.
I would use that for indirect grilling of a chicken (throwing a few small pieces of green apple wood over the charcoal). I pay a high price for that stuff by the bag.
Yep, it is biochar. Perhaps I wasn’t clear when I said put out. It is coals I’m putting out no flame. The only flame in the process is at the beginning with the starter fire. Biochar is simply biomass that is burned in a low oxygen environment. There lots of ways to do it. One is the way you show. The home owner version of that technique is placing the biomass in a 30 gal drum with holes in the bottom to allow the inflow of some air and a single small hole in the top to allow moisture to escape. That 30 gal drum is then placed in a 50 gal drum which has the fire in it. The results look exactly like what you show. I believe this is called a retort version of the kiln. You may be right that it may be more source efficient, I don’t know. The reason I did not use this approach is because it required the result to be run through a wood chipper or something similar to get usable particle size. I don’t have convenient access to a chipper and I have plenty of wood chips.
My kiln is a TLUD. The fire with flames is started on the top and it burns down to coals. Then you add the afterburner. Those coals burn their way down through the biomass. The fire burning from top to bottom limits the amount of oxygen. If you google Top Lit Up Draft Kiln and Biochar, you will find examples of this technique. The reason it needs to be extinguished is that charcoal burns once it is exposed to full oxygen. When my kiln has burned down there is no smoke or fire. When I dump it on the ground and the hot biochar is exposed to Oxygen, it immediately begins to burn. I use a hose to extinguish it so it does not burn to ash.
I don’t stress trees to increase fruit yield. It’s primarily to increase fruit quality. Has the side effect of reducing pruning by reducing growth. Why do something that has the effect of increasing growth? Especially when vigor is often negatively associated with fruit quality.
It is because my application is different. I’m growing trees for wildlife. These are largely trees grown from seeds or nuts. Unlike grafting a mature scion to dwarfed rootstock, these will be full sized trees that require good vegetative growth for year before they start producing mast.
Having said that, I’m not convinced that having a healthy mycorrhizae is only reflected in vegetative growth. It may turn out to have an impact on both yield and quality of fruit. I’m not sure we have a full scientific exploration of this yet. I believe that in general, improving soil health will have an overall beneficial impact on the trees we grow.
I don’t believe biochar is magic or the only means of improving soil health. I believe it is one tool we have that can be effective. How effective is probably related to the condition of the underlying soil and mycorrhizae that exists before you start.
I’ve seen some good reports and studies so far and it is time for some hands-on experience for me.
I’m not suggesting I’ve got any answers for others applications. I’m learning as I go, trying to understand things, and trying to share my progress with others. My expertise is a specialized engineering area, not horticulture. Wildlife management is a hobby for me and I am part owner in a small pine farm. We spend considerable time and treasure each year on non-harvested agriculture for wildlife as part of our forest stewardship plan. My interest in low maintenance mast producing trees is to see if there is some way to establish a permaculture to reduce our time and money spent on agricultural activities while achieving the same effect. We are already using USDA habitat management programs.
I realize there is a lot of hype around things like biochar. I’m trying to understand the underlying science the best I can and get some hands-on experience. I’m not at all convinced it is a solution, but I’m sold enough on the underlying principles to give it a try.
I’m glad you are here sharing your experiences. I hope you will do what most of us never try, which is to actually leave some similar areas untreated so you will have a means to compare the method by way of a control.
I was listening the a farm report Fred Hoffman does every week and he mentions a study in an almond orchard. The new almond orchard was where stone fruit was grown. Half the orchard they dug up the stone fruit trees and burned and spread ashes all over. The other half they ground the old stone fruit trees, and incorporated into the soil. After 3 years the ground part showed higher nutrition in the ground, and in the leaves. Not exactly biochar, but the ashes I’m sure had some biochar Which was not as good than just grinding the trees up. The trees grew the same the first three years, no nitrogen was really tied up by the grindings either. Dr Holtz out of San Joaquin did the study.
Yes, my plan with both the containerized trees as well as the trees planting in the field is to do some with the old proven method and then take a second group and add the charged biochar concoction. Again, I’m not trying to test each of the elements in the concoction. I’m trying to decided if a method using this concoction improves development in my trees. Right now I’m looking purely in terms of growth since they are seedlings. It will be many years before I can compare mast yield or quality.
In all cases I’ll be doing a subjective comparison. I don’t plan to take detailed measurements or do a statistical analysis. Lots of other folks are doing that and providing results. I’m more trying to answer the question as to whether this is beneficial in my application. I’ll try to post some pics over time.
You can see flames coming from the chimney. After the first half hour, there is no more flame at all inside the kiln. If the wood chips were dry, there would essentially be no smoke, but with wet chips, there is a slow release of smoke through the process.
I’m sorry I caught back to this thread so late. This is a fantastic thread. I went to a class on biochar, and I’ve been planning on using it for a long time. Biochar does tend to make soils a bit more alkaline, but that is not a bad thing in our acidic PNW soils. We tend to have heavy clay in Portland, and biochar could open it up for better drainage in our wet winters and better cation and gas exchange for the roots and the mycorrhizae. I think I will use a combo of compost tea and urine to charge it. Excellent pictures and tutorial. THis looks completely practically doable. I want to get my kids fired up. Maybe they will help me on this project. Thanks for showing and explaining all the details. My plan is not organic material in the soil versus biochar. I will be adding organic material as a mulch whether I do biochar or not. The biochar just might increase air and water flow in the heavy clay we have so that worms and microbes can do their jobs.
John S
PDX OR
Having tried urine, I would not recommend it. I did one batch using urine to balance the C:N before using worm casting tea to charge it and I did 2 batches using water soluble AMS instead of urine. In both cases, H20 is the carrier for the N. They recommend a 20:1 C:N for direct soil amendment to mitigate N tie-up in early years… When I did the math estimating my biochar at 100:1 based on using wood chips, it came out to needing 30 gal of urine to balance 15 gal of biochar. There is way more fluid in urine than biochar can absorb at once. It must be added very slowly over time. It was taking so long to evaporate the liquid that I ended up draining it and boiling off much of the liquid and reapplying the more concentrated liquid. It was not a pleasant process.
The AMS went much better to work with. The math showed that I could get the same ratio using 1.8 gal of AMS. Of course I had to dissolve that in water as a carrier, but it took much less water to dissolve it and I could just let the excess liquid evaporate. Much more pleasant!
I’m just now starting to use it with my containerized trees, I’m documenting that over on the QDMA forum where a few others are playing with biochar: Biochar Thread
I also have another thread where I showed my worm casting tea brewing: Worm Casting Tea
I think your view of biochar is similar to mine. I view it largely as changing the tilth of the clay and providing a home for the mycorrhizae. I see this as allowing OM to be built in the soil over time and act as fuel for the microbial life. I think of living soil as the end goal.
Ammonium Sulfate. Fertilizer 21-0-0 - Chemical Formula (NH₄)₂SO₄
I use a water soluble form to amend water before adding herbicides to a sprayer tank. I’ve also used it as a source of sulfur when fertilizing soybeans on fields with insufficient sulfur.
When I did the math assuming a 100:1 C:N for the biochar, it takes about 30 gal of urine to amend 15 gal of bichar. It only takes about 1.8 gal of dry AMS to achieve the same 20:1 C:N ratio. It takes a few gallons of water to dissolve 1.8 gal of dry water soluble AMS, but far less than 30 gal.
Thanks Jack. I love it when people share really practical ideas, so you can actually do it to help your garden/orchard, instead of just thinking about it. I really didn’t like the idea of using anomalous mouse shavings anyway.
John S
PDX OR
