Pete Podurgiel wrote:From my experience, potatoes don't like to be in contact with biochar.
I had some mixed in into my soil where I planted them (I had added wood ash from my stove) and the potatoes ended up with small black crusty spots on the skins in places where they appeared to be in contact with the charcoal.
It didn't seem to hurt the potato or make it inedible, just made for unattractive produce and might not be good for long term storage.
Causation vs correlation? ...I'm unsure. I can't find the source of where I found this explaination, but I haven't had this problem since I stopped planting them in areas with charcoal. YMMV.
John Suavecito wrote:The change in Ph is the reason I'm concerned. Of course, there could be something else as well. That's why I'm asking. That's why sharing experiences like we do on permies will help us figure out what to do for optimal plant growth.
I have thoughts and dreams about using biochar and non-inoculated pyrolisis produced char as surface mulch in my gardens (mixed with chopped straw and leaves maybe). My hope is that this will create slow incorporation, without tilling, while providing many of the benefits of mulch while alsor providing a black surface which will increase heat in my cold sensitive area. I would limit this type of mulch directly around strawberries or potatoes unless I added a lot of peat, some forest soil, or a trace of agricultural grade sulfur. I have a local source of peat (a farmer dug up a lot to make a pond and said I can come any time to get it, and he will load my truck, and the local poplar forests create a nice low acid high fungal soil and mulch, so for me, I am rich in possible additions for biochar.
I use the char I sift from my ashes as mulch around plants in containers in its coarse state. So far I have not had any plants seem to suffer from it.
Roberto pokachinni wrote:
My hope is that this will create slow incorporation, without tilling, while providing many of the benefits of mulch while also providing a black surface which will increase heat in my cold sensitive area.
Roberto, I have spread biochar (first soaked in urine) a half dozen places on the surface in my yard. From March 10 to May 10. I am testing the temperature, moisture, and PH of the soil directly under the char and 1 foot nearby every 4 or 5 days. Consistently, the soil underneath is cooler and wetter! Wetter is to be expected; it acts like any mulch to preserve moisture. But cooler, in spite of being a black surface? I will now try testing it during the night; maybe it will be warmer than the surrounding soil. Quite possibly, the extra moisture is making the temperature more stable. In any event, consistently, seeds sprout more quickly than under 3 other different mulches or no mulch, and grass has doubled the growth of that in nearby soil. PH testing has had erratic results so far.