I've got a brand new, empty raised bed in the backyard. It's on the south side of my house, in full sun, and I built it out of 50/50 topsoil/compost. It's roughly 4 feet by 12 feet, and after a full winter's compaction it's roughly a foot and a half high.
The native woodland soil was scraped away when my house was built in early 2005, so this new raised bed was built over grass which is basically growing on gooey grey/blue clay.
Out in the garage I've got ~60 lbs of glacial rock dust, ~50 lbs of greensand, ~40 lbs each of rock phosphate & azomite, ~30 lbs of agricultural gypsum, ~20 lbs each of kelp meal, alfalfa pellets & bone meal, ~15 lbs of Cowboy Charcoal (suitable for making biochar), & 10 lbs of Sea Agri sea salt. I've got a pound of mycorrhiza (beneficial fungus) mix, packaged in 2010. I also have a pound or two each of the following inoculated cover crop seeds (from 2010): yellow berseem clover, white clover, crimson clover, hairy vetch, biomaster peas, & buckwheat.
I've got many, many packets of veggie & herb seeds, a compost pile that's about 4 x 3 x 10 feet, and lots of unplanted bulbs from November.
If you were me, what experiments or trials would you conduct? I'm willing to spend another $50 for plants if a really cool idea requires it.
I don't know about that Sea Agri stuff. Sounds like baloney, especially if you have clay, which you do. The good thing about clay is that it is chock full of minerals. You can plant stuff that gets a tap root to pull the minerals up into the new soil you put down and then compost that right there.
At any rate, if it were me and I had this small raised plot, I would be planting heirloom root crops, like Crapaudine beets, because my entire yard is pretty much over-run with tree roots, so there is real difficult with growing root crops, and I enjoy pickled beets, roasted turnips, and such. IOW, I would grow something I have always wanted to grow, considering this plot a sort of jewel box. What is it that you have always wanted to grow?
Oh, I've only had my own place for six years, so the list of stuff I want to grow is loooong. I've got lots of space to grow anything I want. What I'm hoping to do in this bed are some side-by-side comparisons to see whether & how much certain soil amendments help.
Thats a lotta amendments= are you independently wealthy or something? Just kidding, I balk at the cost.
Greensand, rock dustm azomite, and Se Agri--I think thos are somewhat similarly intended for trace mineral help.
Rock phosphate, more specific. Gypsum, don't know much about, Kelp traces and N? Alfalfa much N, bonemeal, Phos?
I would make that bed into sections, using some alfalfa and bonemeal on all cuz you have it, and using ONE of the mineral amendments on each section, and plant a patch of the same kind of seeds in each.
I think LariAnn wrote about Sea Agri- it sounded good there- trace minerals stuff, like azomite. Is that it Pirate?
One of these days I'll open up the analysis on all these minerals and compare them. That one is big on some good things (Mg,Mn,P,K,Ca) but lots of those others are in the parts of ppm hpwever I don't know that anyone says plants require lithium for example.
What I suggested above does not leave a space for "no" mineral amendments which would be a good comparison.
Where did you get you "I've got a pound of mycorrhiza (beneficial fungus) mix", or what's its commercial name? I'm looking for something like that.
I think you have sources of mineral nutrients well in hand, although I thought you might mention "50# of urea", or superphosphate, or 'a few bags of generic balanced NPK". Until you get your soil rich and lively, it may need a little help with the plain old macro nutirients.
It is possible (I'm not sure) that adding expensive amendments to hard clay might be wastefull. If they run off and are whased away, you'll only bebefit your downslope neighbors. Maybe first get some "tilth" into the clay. If it is friable and drainable enough to hold some water, then start mixing that great stuff into it, and expect to stay aorund on your proerty.
I thihnk the first and formost need for amending heavy clay is organic matter: compost, mulch, green manure, tillage, leaves, manure, coffee grounds, shredded paper, cardboard, you name it. That's old news, but I think it is the First Commandment for turning "dirt" into "soil".
Great! You said you had lots of room? Plant lots of cover crops! Remember that the roots contrbute as much carbon as the stems and leaves. Turn some under, and mow some into your compost heaps.
If you can grow cover crops that reseed, all the better. Som eone said that you can grow buckwheat longer than most people do, let it go to seed, turn it under, and it will re-seed.
If the innoculant is fresh on your peas, cool, you'll get some N that way. save some peas and re-plant.
Consider 'tillage radishes' or oilseed radishes, just becuase they drill deep holes. Maybe Fall Rye. You have something against alfalfa?
Set up several compost heaps!
Grow or acquire as much compostable matter as possible. Biosolids, yard waste, clippings, leaves, restaurant waste, sawdust, whatever.
Do some sheet composting.
Lay down cardboard and do "lasagna composting", if that is different from sheet composting.
After you add LOTS of organic matter, almost any other method you use will succeed wonderfully. If you don't add lots of organic matter, nothing is likely to help.
Me, personally, I seem to be in a minority in this century, but I think it is valuable to TILL very heavy raw clay, turn it over, get something into it fairly deep that supports drainage and aeration WHILE you are building up some organic matter in it. I would say that even your cover crops will thank you if you can break that clay up and amend it at least a little before they try to drive their roots down into it for the first time. YMMV.
Crushed rock, grit, coarse sand, rock powder, ground pine bark, sawdust-plus-a-nitrogen-source, chipped brush, old phone books, any kind of chopped organic matter at all, anything that slows down the way that clay wants to compact itself, prevent drainage and aeration, and exclude all oxygen from the roots.
Maybe you have some sandy subsoil under that clay? Or in one corner of your yard? Mixing them will produce something no worse than the clay is already, in terms of being prone to compactioon, and being hard when dry. However, adding grit to clay will encourage it to keep draining IF it also has organic matter being added.
It is best to till huge amounts of composted organic under, but I assume that you have more clay than you have compost. Until you have enough finished compost that you can cover your land 6-12" deep, several years in a row, that dead soggy clay will benefit from tilling SOMETHING into it right away. Then keep adding compost to the top, and some year fairly soon you won't NEED to till things under to keep the clay from turning back into concrete.
In the meanwhile, remember that any weight at all will COMPACT that clay back down into something hard and anoxic. After breaking, plowing or tilling, don't walk on it or drive over it any more than you need to.
Consider amending it just 50% or 30% at a time: turn 1/3rd or 1/2 of the yard into piled-up raised beds, and only walk between the beds, not on them. Maybe grow cover crops on the walkways, but stay off the clay that you are trying to turn into soil.
Oh yes: give extra care to the drainage, i.e. the grading of your clay. Since it probably perks hardly at all, you want to divert the runoff, and also encourage anything you are amending to DRAIN so that the raw-clay-becoming-soil remains aerobic. Maybe large-scale-bulldozer-grading. Maybe tiling, or just some slit trenches for now. But identify the low spots that you want water to drain TO, and consider what it will do after it gets there.
That will be less critical once much of your yard has 5-20% organic content in the top 12-20", so that it is more likely to recover from rain, draining and not compacting right away.
This area of Ohio's as flat as a pancake. Nothing's going to wash away.
The raised bed is 50% compost right now.
What I'm looking for is ideas on what amendments to evaluate & how. Has anybody here been wondering, for example, "what happens when hot peppers are grown in rock dust vs. Azomite vs. greensand vs. plain soil?" That kind of thing.
One great experiment to do is to collect a little soil from 10 spots in your yard, with clean tools, mix it, and pay for an analysis. The "AHA" that comes from that might save you years and hundreds of dollars, in reaching the point you want to reach.
Especially: Mix your rasied bed well, and have that analyzed. You might well be surprised at the pH, or salinity, or a nutirent or micronutrient lack or excess. Fixing the wrong problems is a slow and expensive way to reach the goal!
Just one micronutrient or "middle nutrient" in conspicuous absence could be a $10, one afternoon fix that would otherwise plauge you and sabotage your best efforts for years. And the best time for an analysis is BEFORE you add verying amounts of this and that, here and there. Get the baseline known while there is still a baseline.
And a county Ag agent may well have advice that has stood the test of time in YOUR locale. First do the obvious things that usually work pretty well. THEN improve on success.
Two experimental methods I really liked: pick two things you think your soil might need, like micronutrients and mycorhyzzia. Or rock phosphate and greensand. Plant a wide area with something uniform, like a cover crop mix. (Probably a mix will be more informative than just one crop.)
Lay out a big square divided into quarters. Spread a goodly bit of rock phosphate on the two West quarters. Spread greensand on the two South quarters. The Northeast corner is your control: it has nothing added. The SouthWest corner got both, and tells you how much benefit you can get from that combination. If the whole benefit came ffrom just one item (say phosphate), both West quarters will look about the same, pretty good, and the two East quarters will look the same: no improvment.
(However, from the sound of "gooey grey/blue clay", first your yard needs EVERYTHING. Especially composted or raw organic matter, and something coarse for drainage. THEN, this or that may improve soil that's mechanically usable and capable of supporting life and roots. But if there is no drainage and no aeration, nothing in your shed is going to make much grow.)
Your amendments sound like you respect the organic approach. I'm sure those principles work really well and have major advantages maintaining great, good, average and poor soils, but they MAY need some chemical help while rescuing dead clay that's worse than subsoil. Consider helping those cover crops out, maybe just for the first few years, with some NPK fertilizer - not going overboard, just a little, with a low rate of application.
Think of it as a blood transfusion or a splint, that a patient may need before he's healthy enough that all he needs is a healthy diet and exercise.
It's great to feed the soil, and cover crops are a great way to feed the soil, but with raw dead clay, maybe you'll need to feed the cover crops before they can thrive enough TO feed the soil! Try it, with some divided squares. If a little chemical fertilizer still helps the plants, then your clay still needs a lot more help, like a LOT more organic matter.
Another experimental technique: get a small spreader, as for lime or fertilizer. Treat most of a partly-amended large area uniformly: give it a little of everything you think it needs, UNIFORMLY. Then fill the spreader with something special, say Azomite. Pick part of your yard and lay down big block letters, or flowing script, spelling out "AZOMITE" in letters 10 feet tall.
Do the same with diluted mychorhozzia, spelling "FUNGUS".
Again with "KELP", micronutrient "M-NUTS", etc.
Now you don't even need to keep track of what went where. By midsummer, whatever your yard needs more of will shout out at you in darker-green letters 10 feet high. You will know that more of THAT is needed.
If anything is spelled out in wilted or stunted letters, you know you have too much of that, and need to spread it around to dilute it, or at least add no more.
Have you considered sources of Ca, Mg, and Iron? Maybe something chelated to help solublize whatever is already in the clay? The gypsum should add sulphate, and "they say" the Ca helps clay combine with other things to form clods.
I don't know any partulars of individual crops needing more of one thing than another. Just some things (lettuce?) want frequent, light fertilization, or macro nutrients plentifully available at all times. Other things might want a leaner mix, especiqally less N, when they start producing fruits.
>> This area of Ohio's as flat as a pancake. Nothing's going to wash away.
Then "some of everything, especially compost" is likely to benefit the yard where it's still mostly clay.
I can't say much about your rich raised bed - "good soil" is something I never used to have. Just this year, two of my beds have crossed over from "terrible to poor" and have beocme "Hey - not too bad!" in the top 12".
With that caution, I will say that I never thought of certain plants having particular needs for certain micronutrients. I expect them to have peculiar needs like "constantly moist soil" or "well-drained" or "full sun". Perhaps "heavy feeder" or "don't overfertilize after flowering".
I think of the soil as having specifric needs, until it has 'enioguh of everythiung". And that is best determined by analysis.
Hopefully people who know about special needs of certain crops will enlighten us.
Thanks for the input, Corey. I'm not going to put much effort into the lawn, because it seems to be doing fine.
I'm interested in running tests/trials in the raised bed, to see how different soil amendments work. I don't need help improving this particular bed because it's 50/50 bulk-bought topsoil and finished compost. It's the perfect blank slate, and I'm inviting everybody here to scribble on it from a distance. I'll try the coolest ideas y'all can come up with, & I'll post pictures of the results.
This is an opportunity for you guys to play in my dirt on my dime for a whole growing season.
My last soil analysis from U MD (fiften years ago) did not give any thing beyond texture (sand/silt clay) , NPK,Mg, pH...thats about it. When I looked for a soil lab recently (because U MD no longer does them cheapie or at all) it was $50 for micronutrients. I'd rather put my $50 into the actual amendments which for my rainy sandy based soil are likely needed.
Pirate-- I'll stick with my previous proposal, and suggest your crops be from a couple different families.
Peppers/ tomatos / potatos
Spinach, beets, chard
You'll have to decide how MUCH to use, you want to be sure its enough for a difference to appear
You might consider taking a cup or so of the amendments also and marking off some squares in the lawn. Test them that way. Just sprinkle them on and see what happens.
Personally, I agree with Rick Corey. Your soil doesn't need mineral soil amendments. It needs organic additions, like green manure. Clay already has tons of minerals. What it needs is something to fluff it up so that those nutrients are made available to roots. That's why both I and Rick Corey suggested something with taproots to aerate the clay and to pull up nutrients to the top layer and to then compost in place.
I myself also till, and I till in the white clover or peas that I plant every year in my clay, which is not even considered as good as topsoil because analysis shows it is 1/3 rock fragments. Talk about minerals! But I am able to grow just fine in it because of the tilling and green manure. I don't add any supplements except for organic NPK type sources, as Rick Corey mentioned, like soy meal, and in the past, a top dressing around stuff like tomatoes of composted manure. The only foliar fert I use is liquid kelp, nothing fancy. And it works, because for instance, in this soil I have grown enough tomatoes to make sauce to last me until the following season. Clay gets a very bad rap, but it is actually chock full of plant nutrients. It only needs to be opened. Tilling in green manures is an excellent way to do that--and it's traditional, too. There are entire books written in the 19th century on using green manures.
Everyone needs a hobby, and this experiment with the raised bed is yours, but I do not see how it will benefit your gardening situation in general unless you plan to make your entire garden over in raised beds with imported compost and mineral supplements. To me, that just seems like creating a difficult artificial environment to avoid dealing with a natural environment that is actually easy to work with. But whatever floats your boat.
Yikes! $50 for a micro-nutrient analysis? BZZZT. At that price, I would rather ask what my whole county tends to need, and add a little or a lot of that in some spots, to see what the point of diminishing returns was. Or, as suggested: just add a little of everything everywhere and trust that I won't go far over necessity and into excess, by using mineral sources of low solubility.
I think I misunderstood when I heard "large yard full of heavy clay", because that is my eager hobby or greatest interest (maybe I'm perverse).
I think PuddlePirate is more interested in fine-tuning his already-compost-rich RB, than in improving the rest of his yard or lawn. (My only interest in a lawn would be as a source of grass clippings for compost. And I'd rather plant it to buckwheat or Fall Rye, than ryegrass.)
But that leaves me with no ideas or suggestions ... what do you do if your soil is ALREADY great?
All I can think of, besides the good idea above of "plant a variety of families", might be "right angle stripes" of amendments.
Say you've planted rows of things that you like, or are interested in, or think might be challeneges, running North and South.
Try laying down the amendments that you think might have the most benefit in stripes running East and West. To see the benefit despite diffusion, a stripe might need to be 18-24" wide.
If one or several species are conspicuously happier where their rows intersect that stripe, lay down about that much of that amendment everywhere. Next year, lay down another stipe to bring the concentration up higher, to see if you've exceeded the point of diminishing returns.
Mostly, though: plant what you like to eat or look at. Or pick something new to you that might be an interesting challenge. It seems that experienced gardeners with great, big, green thumbs tend to develop "zone envy" and try to grow things that need climates they don't have! Talk about CHALLENGE!
PuddlePirate, if you still have the cowboy charcoal and mycorrhiza, I'd mix the two in water and test a couple areas with and without the mix. The idea being that the biochar keeps more nutrients available to your plants.
I've been looking a lot in to biochar, and think it is a great idea. One thing I've read is that it is a good Idea to inoculate the charcoal before adding it to your soil.
Most of what I've been learning is how to make biochar from youtube video's. My thinking being, to use what you have around the yard and sequestering that carbon in the soil.
The test would be to see if plants grew better with biochar and a lower than normal fertilizing regiment. Though I'm sure your test plot is no longer vacant.