I've been reading some articles about biochar. For anyone who in not familiar with biochar, it is organic material (wood, straw, plant residues) that has been heated super hot with almost no oxygen. The result is like a black perlite - a very high carbon material with high internal and external surface area. Added to soil, it's meant to improve water properties, aeration, pH, plant nutrition, drainage. Apparently a version of biochar was used by ancient Amazonian peoples, and persists in the soil to this day. Some people claim big improvements. Research is mixed. USDA on Biochar. Science Direct on Biochar. Garden Myths on Biochar. There's a lot of people out there promoting it, and others saying, wait a minute, not so sure. I don't know. I was thinking about adding biochar to my raised beds. Some have purchased topsoil. Who knows where it originally comes from. The place where I bought it accepts all kinds of yard waste. They said especially sod, they sift it with a 1/2 inch mesh and combine it all together. I imagine that sod was lawn grass and some chemicals might have been used, and some grass roots and leaves might contribute organic matter. Last year I built two beds with it, mixed with home made compost, and it grew great garlic, onions, lettuce, and peppers. My thought now is, the biochar might improve water retention so I don't need to water as much, and also help buffer the pH and even out soil nutrition. But I just don't know. Also, it does cost money. I guess for a one time investment it would be OK. Maybe my Christmas present to myself?
Why not just build your own compost bed ! Cheaper and you know whats in it ! Summer heat will solarize it !
Oh honey, gardening is simple. You replace nutrients from the previous year's crop, plant, and weed. As Mart suggested, build your own compost. I don't and won't accept bags of grass clippings, leaves, or anything else from someone else's garden or yard. Let your Christmas present to yourself be a nice compost bin near your garden. You'll enjoy it for years, and so will your soil!
Don’t forget layering old wood/logs to the bottom of raised beds. The water retention after a couple of years (shorter time if they are rotted already) is amazing. For more information look up huglekultur.
Daniel - the ladies are right. But since some people like me just gotta know A to Z let me jump start you from where you left off. It is a huge subject. You are talking carbon and we are carbon based life forms. To say it is a pervasive subject is an understatement. One worth pursuing, but literally global. My thumbing a book out here is problematic so I will try for some high points I found interesting that also supports what the ladies are expressing. The reason soil results are mixed is simply that some soil types already have carbon and adding more shows less or no effect. Premixed soil for example. My yard clay is like the Terra Preta soils in the Amazon (Ultisols as in Ultimate or last one standing). Wetness washes away liming agents like calcium and magnesium and makes it acid. It is old and ground densely and fine and with very low remaining organic matter. We benefit from things that hold oxygen space like biochar. Compost works well, but gets digested annually where Biochar lasts for centuries. In fact it is this longevity that is the most attractive aspect of the stuff. There is some electrical charge detail related to its oxidized surface area you should read (why it holds nutrients and supports the biodome) but I want to mention getting that pure carbon is expensive energy wise. It is so high temperature all organic materials are stripped away. 700 Celsius or 1300f. That is a problem for brush piles, my weber grill, or most homegrown methods. I promise you those amazonians did not get their bio-char that way. Theirs came from piss-pots which was not far from the Romans composting in clay urns in a similiar fashion. Everything from the cook fire became the next bathroom which became the next fertilizer. Ashes are liming agents raising acidic soil pH and adding potassium and minerals. For them it worked out. It was not a fertilizer exactly where it ultimately supported soil life. Via enzymatic action the biodome could dissolve the minerals in the soil and leave them in a plant nutrient form. Even today the indians will sell the topsoil, because it literally grows back from the mass of dead bacterial and fungal spawn. Locally it is easier to get most of the organics out of homemade charcoal and let the same process that digests compost continue to work on the remaining organic bits until it is the pure carbon you are seeking. Like the amazonian indians, make charcoals and put that out in the compost. It takes some years to get going, but every year a little more oxidation has occurred, and your bio-char emerges from the charcoal or char if you prefer a volume method. Some of this question is in part coming from the "NPK is the only fertilizer" idea. The internet is made for selling products so some things like Oxygen and Hydrogen are left out of common discussions. The macronutrients plants require are carbon, nitrogen, hydrogen, oxygen, phosphorus, potassium, calcium, magnesium, and sulfur. Important micronutrients include iron, manganese, boron, molybdenum, copper, zinc, chlorine, nickel, cobalt, silicon and sodium. You know testing for these is probably the most important thing. But these are not all readily available to a plant. Most have to be digested and prepared in some way. It is the biodome that eats rock and poops fertilizer as a result. Or one could say just dies and leaves nutrient rich organic matter. That is what milorganite is made of and why the amazon soils grow back. Dead bodies full of what they broke down while alive. Sorry I was so windy, there is just so much more there that it is hard to stop. Compost does the same thing though. It is just hard to beat 54 feet deep ancient supersoil full of biodome that has over millenia established relationships with plants.
Thank you so much everyone for your thoughtful comments! It's an interesting topic and I have been thinking about it. I always compost all of our garden waste and kitchen waste. I do set aside coffee grounds and eggshells, which I work into the top layers of the garden raised beds, as soon as they are produced. Also, we have a woodstove. I add a lot of dry chicken bones to our stove fire too, and they add calcium and phosphorus to the ashes. I spread the ashes lightly, not wanting to overdo it. My soil is acidic, low mineral - except iron is high and potassium fairly high- low calcium, low magnesium. After all that work building up the soil, now I added new raised beds that are really deep. That is because I'm losing strength and energy, and my joints hurt. The high beds are amazing at how much better I can grow things. But with the soil, I had to start over. I added what compost I have to the layer that's about a foot from the top surface. Also a layer of tree leaves. The top is a foot thick layer from a raised bed that had garlic, then green beans this year. It has a great mycelium content, from the looks of the soil I dug up. And a lot of earthworms. I worry a little about using compost from my garden crops. I don't want to infest my crops with fusarium wilt or verticillium wilt or other diseases. I do a three year rotation but the raised beds only have room for two year rotation. My compost heap is not the hot type, just plant matter that decomposes over a year or two. I can't really have separate heaps for tomato stalks, peppers, squashes, sweetcorn, potatoes, onion and garlic stalks. That's why I was thinking about the biochar, which should last a very long time and also might loosen up my soil drainage, sort of like perlite, and also raise the pH a bit and help some with water. Anyway, you all make some great, thoughtful comments and I really appreciate it! Thank you! Here are the raised beds as of yesterday. Just finished adding soil... Then a blanket of tree leaves for the winter. There is one more raised bed to rebuild, a wood plank sided raised bed that was destroyed by moles. It will have to get recycled commercial topsoil - I'm out of the good stuff I built up over the years.
This is the way. I know I quit using my chipper shredder and went to a fire pit for reasons like these. It works better for my situation anyway. Now if you can share anything easy about killing off RKN......
"Now if you can share anything easy about killing off RKN......" Dirt Mechanic, I'm not aware that I have that pest. University of Wisconsin states - Grow French Marigolds, which produce a substance toxic to the nematodes. I plant these all over the place. They are small and easy to save seeds for next year. Use a crop rotation or cover crop of plants they don't like, such as corn, wheat, oats or rye. I do rotations as best I can. Have lots of organic matter. Use compost or leaf mulch, which can encourage growth of predators or pathogens of nematodes. Keep the ground clear of broadleaf weeds, that are feed sources for the nematodes. Source Or.... maybe add biochar? Biochar and RKN And Biochar and RKN and Biochar and Plant Pathogens There's more in a search. Such as Science Direct. Trouble is, the stuff is so expensive, and let the buyer beware, a lot of what comes up on searches is biochar mixed with cheaper stuff, like composts. Lowes has some - after the holiday rush, I might see if I can invest in some.
Thank you! I will make time to read all of that. It takes me a while on papers, sometimes I have to look up words that are not clear to me.
DirtMechanic, I read this informative article hat seems pretty accessible and scholarly at the same time Nematodes:Alternative Controls I liked some ideas there and plan to use them, especially cover crops of Nemagon mustard and Golden Guardian marigolds. I don't know that I can use them as companion planting but I can fit them in as cover crops. Also, the marigold effect seems both as root based with live plants, but also leaf matter. So maybe I can grow them in a separate area - they grow big - and cut them down and use them as mulch. I dont know. I found the seeds on several website sources.
