Well, first, every potting mix is different and everyone's garden is different. Every recipe is different. Recipe amounts are recommended and not set in stone. The "4-5 cups/CF" amounts originally came from Gaia Green GRD research trials some time ago. If my memory serves me correctly the benefits ran out at around 5-6 cups/CF. BAS, in their Pioneer Valley Brix Blend basalt shows "May be incorporated into potting soil mixes up to 5% by volume depending on soils and plantings." (http://buildasoil.com/products/rock-dust-local-premium-basalt). I've never used the compost method you're talking about Waktoo so can't comment. My own potting mix IS 100% OM before I add rock flour. I've never seen anything remotely like it turning to concrete at those rate but hey, maybe others are having different results. Who knows. I do think there's something wrong happening tho if adding 3%-4% Rock dust to a largely organic matter mix is changing the structure of the soil that much. Then again, everybody has a different soil recipe so I don't know what others results might be like. J
FWIW, local, from a landscape supply, 5 gallon bucket full of granite meal= $3. Weighs ~60lb and you supply the bucket and shovel. Guess a good price is relative. Wet
I used it for years with no issues but asked about using it once and coot and i got into a large discussion where i was educated by him lol, so ive been trying to find other sources since, like oyster shell powder, something as an alternative like gypsum and epsom salts to mix in. The goal is no till at the end of the day, huge smart pots so i i can do water only and the occasional SST. I was just concerned after il earned from coot that the ratio is supposed to be 5/6:1 vs the odd ratio of DL. Apparently it has much more magnesium than is needed. I heard that farmers only use it every 5-6 years and wondered maybe im doin somethin wrong. And then seems most organic gardeners cant agree precisely so confidence can turn to confusion rather quickly. Heres the sources i was provided: http://www.everwoodfarm.com/index.php?main_page=advanced_search_result&search_in_description=1&keyword=glacial+rock+dust&x=-238&y=-426 http://www.fertilizeronline.com/rockdust.php And of course BAS. Please tell your thoughts. And thank you very much. ~ poke
I used to do this and my soil was to dense and heavy, cut in half works perfect. With 4 cups had to add so much pearlite to get good drainage. I have plenty of Santa's beard growing in my soil. This works way better for my needs Happy Growing Growmie! Sent from my iPhone using Grasscity Forum mobile app
Although I certainly don't have the wisdom and experience the likes of the people posting here, I can give my experience. Using ITG's beginner mix of 1/3 peat, EWC and aeration (perlite), my mix felt too heavy after I added 4+ cups of rock dust to it. The reason I believe is with my own homemade castings (which are on the heavy/thick side) as well as adding gypsum plus the amount of rock dust mentioned above to this mix it was very heavy and my mix had to be reworked. I guess what I am trying to say is I agree with you jerry when you said above: "every potting mix is different and everyone's garden is different. Every recipe is different. Recipe amounts are recommended and not set in stone..." and "...everybody has a different soil recipe so I don't know what others results might be like." Like I said this is just my limited experience. Nice discussion going on here.
The first and last statements get right to the heart of the matter IMO. Especially the 'not set in stone' bit. Use what works for you. Wet
I am very fortunate my local Farm Supply Store carries 10lb of the aggrowinn MRD. I can't remeber the price because I have the worst case of CRS. Lol! I Think 14-16 bucks. A couple of years ago I was able to find some 50lb bags of GRD the guy bought a pallet full and was kind enough to let me take 3 bags. (On Craigslist $26 each) Just about gone. I mix a heaping cup GRD and a heaping cup of MRD. Per CF. Seems to be working fine and my soil drains better. Just my finding. Sent from my iPhone using Grasscity Forum mobile app
I need to get my butt in gear and start showin my face at some of these local places. See what they have. Going in person seems to have a greater impact than a phone call.
Rinse it well before you use it should be fine. Some fabricators use dry diamond blades to cut and polish. The amount of contaminants would be minimal in any case. I understand this argument as I am surrounded by chicken, horse, goats and dairy. I do not use this free compost. I talk to all the local farmers and they don't just feed there animals feed...... Half the time even if you go all OMRI I don't think you really know what other goodies are in your soil. The local soil vendor Kellogg buys all it's OMRI stuff from these same local farmers.... My next door neighbor worked for them for almost a year. What you Put in one end comes out the other. As a good friend told me one night as we stood shoulder to shoulder at the local watering hole at the urinals. It's a shame we just get to lease this beer. Sent from my iPhone using Grasscity Forum mobile app
My thoughts are your very first words; "I used it for years with no issues". What more needs to be said? Wet
I think Jerry covered this by saying everyone's mix is a little different, and everyone has a little different results. My current mix is 4c rock dust, 1/2c gypsum, and 1/2c oyster shell. For me personally, it did not make the mix overly heavy or compacted (at least not imo). We'll see how they look after a couple rounds of notill. I would shop local first for sure. Shipping rock dust is damn expensive. If all else fails, Rock Dust Local sells 35# boxes of microfine basalt for $28.50 shipping included. I had an excellent experience purching through them. Fast, cheap, just what I ordered, etc. P-
I'm going to wholeheartedly and completely agree with you here Wetdog. We're all after a single goal - to be fabulously wealthy and have gardeners throughout our compounds - no, wait a minute I'm just kidding - in all seriousness, to simply grow the healthiest plants we can with the simplest, easiest and least expensive means possible. Maybe sometimes there are better ways - who knows? Sometimes I feel like - who cares, providing my garden is happy and healthy? Ya know, this could be any kind of website on any subject and we'd all disagree on something - guaranteed lol - BUT at the end of the day healthy plants is what we're after. I get so damn busy sometimes that I'm so happy that my gardens require the most minimal of care or otherwise I might not even be able to garden and that would be bad. I would like to not have to work any more tho lol J
I want to thank everyone for making this an interesting discussion! wetdog you wrote : I also think that the 'problems' with dolomite are the result of soil studies and trying to transpose them to soiless container mixes. I've been using dolomite for years and have never had a problem with my container mixes. I DO take heed of these studies when it comes to dolomite and my (mostly red clay), soil garden, but not my peat based soiless container mixes. are you saying that the idea of a higher cal/mag ratio is more important in an outdoor garden than a container mix? is this because of the high proportion of organic matter in a soilless mix? i'm just trying to understand, thanks! CJ
I'd also like to point out that jerry utilizes some extremely fluffy, leaf + manure based compost for his main "base" OM input, so I imagine he could easily outdo the rock dust limitation that heavier compost/OM wouldn't allow for, aeration wise. Soon, I too shall witness the glorious tilth that proper leaf mold brings to a potting soil...
This spring I should have a little bit ready at a friends house. Hes been stockpiling a corner of his yard with leaves for years and I get first dibs on any usable material, provided I do all the labor (moving/screening/storing). He seems happy to find another use for it and to clear some space up, not to mention it'll help with his garden next season, while I get some premium material for soil building. Should be a good deal.
SOON in organics ALWAYS means NEXT YEAR, doncha know??? :lol: no matter who or when you ask, sometime next year. Then years later it's always, remember a few years ago when I said I was gonna do such and such LOL
Been without a keyboard for several days. A 'good idea'........ wasn't. In a very brief nutshell the soil study was about dolomite adding too much Mg to soils that were already rich in it and producing lockouts and other problems. Container mixes contain no pre-existing Mg, just what you add. My soil garden might, IDK, but I bear that study in mind when I'm liming the soil garden. I add more Ca by way of gypsum to both soil and containers. I really don't think about the ratios all that much, as long as both are in adequate supply. I leave the complicated math for the plants to figure out. Wet
[quote name="waktoo" post="20985190" timestamp="1417040961"]Solubility/reactivity/atomic weight.Dolo' is a sedimentary rock. The cal'/mag' in dolo' is made readily available much more easily than that contained within basalt, which is an igneous rock. The minerals in dolo' are considered slow release, whereas those in basalt are REALLY slow release. Not to mention that when you consider the actual atomic weight of the cal/mag contained within basalt (you must subtract the "oxide" from the atomic weight), the ratios are even smaller, more like .65% calcium to .0347% magnesium. Compared to dolomite, the amount of cal'/mag' is almost negligible...[/quot Ohhh, look at the big brain on Brad.....thanks for that informative and most excellent answer. I find through and insightful answers like that MOST helpful. Thanks again for the clarity.