Is this a good plan for my super-clay soil...?

On my future land (which I have free but sporadic access to until I buy it), there's a fenced in area against the house where I plan on putting my kitchen garden. It's about 22' x 26'. Twenty years ago the house was built, and in that area my dad put down thick plastic with mulch over it, intending a dog area. It was barely used as such, and weeds (mostly goldenrod) took hold, both above and below the plastic, and for most of this time it decayed & regrew every year, creating 2-3 inches of a lovely texture soil on top of the plastic. This past summer we pulled up all the plastic and hand pulled as much goldenrod as humanly possible (I know I'll be fighting it for a long time). Right under the plastic was solid CLAY. Like, mold-your-grandma-an-ashtray clay.

LAST year, in a small area (3' x 12'?) I hand dug a bit and I layered organic matter, planting some seeds to experiment. Of 9 types of veggies, I got a small pumpkin, lol. Root veggies were thin inedible roots that I couldn't even dig out of the clay, though their leaves would have been edible. I found a mullein plant (which has a long story and was a blessing & a good omen) and I scattered some of its seeds, after reading that the roots go down deep. There are now about 20 mullein plants in a 3'x 12' area.

THIS SPRING, I want to: Plant lots of daikon all over! I plan to let it grow all summer, and at my last fall visit, I'll chop & drop it, add horse manure (free from a neighbor) and then hay as a mulch (also free, from my own land).
Does that sound good?
Is there something I should plant along with the daikon, like a nitrogen fixer?
Is the manure a good idea after chop & drop, so the microbes from it will go down into the daikon and multiply & go to work for me?
Is hay on top a good or bad idea for the winter? I'm afraid its seeds will grow but I read here that a lot of people say that's not an issue. In my small suburban garden the grass took over my food, so I'm wary of that happening again. But it's free and I cannot afford anything else, though I was thinking of asking a neighbor with a wood chipper to help me; there's lots of random brush I want to get rid of.

Thanks to browsing this site, I've done some homework, now please correct me or make suggestions, Oh Wise Ones!

In a section of my yard that has clay soil I planted tree collards, tall kale varieties, and sylvetta arugula. It seems to be doing pretty well, and they are all basically perennial or self sowing in my zone (zone 10). Brassica type plants in general can flourish in clay soil. You could start with those, then down the road add runner beans to further improve the soil and grow up the tree collards and kale stalks.

I think you are looking in the right direction. I would hot compost the horse manure first for weed reduction, and to make the N more stable, with arborist woodchips, straw, and/or your hay and various weeds. Look up Dr. Elaine Ingham's composting recipes for more info. I would loosen the clay with a broadfork or digging fork, add a layer of sticks and then add the finished (not hot anymore) compost. Daikon is a good choice, but diversity is always better for soil life. Nitrogen fixators will be suppressed by the N in the horse manure, so they could be redundant together if resources are scarce. I like wild bird seed as a filler for a cheap bulk soil building mix, as birds will bring their own microbes and nutrients to the party. Locally native wildflowers are also a good addition if seed is available, but would probably not benefit from horse manure much. Horse manure is good for green growth, and can be much less helpful for flowers and fruit.

In your situation, I'd probably try to get as much manure and compost as possible and build a big huge hot pile on there this winter/spring. You need organic matter- the more, the better. Look into free resources like stable manure, chicken manure, sawdust, free bark, seaweed, coffee grounds, mushroom compost, leaves, compost give-aways, etc . Search craigslist and facebook. Then I'd make raised beds in the summer and plant a bunch of easy veggies and legumes- stuff like peas, beans (several kinds), lettuce, tomato transplants, peppers, squash. I'd get a bag or two of composted chicken manure to get stuff going. Daikon might be good, but only if it can penetrate the soil. Daikon doesn't do much in pure hard clay, although the pods are sometimes good to eat. It grows wild in my clay garden and just reseeds itself without making big long roots. But I prefer the small radishes like easter egg for fast edible root crops and legumes like crimson clover and fava beans for soil build-up and nitrogen. Daikon is also good in orchards- the flowers attract bees.

I always try to avoid hay. It almost always has lots of grass and weed seeds. Grass is the enemy. Straw is OK. Try to get  the neighbor's chipper and chip everything you can. See if you can get clean, free chips delivered. Fresh, green, leafy hardwood chips make excellent mulch. The big woody stuff could go into a hugelkultur bed or used as bedliners. There's all kinds of stuff on this website about hugelkultur and chips. Experiment with hugelkultur. Just my 2 cents...

Good luck!

Kim,

I have hard clay myself, so I understand the predicament. Not sure how hard your clay is, but daikon is not some miracle plant, if the clay is tough enough, it will not drill itself into the soil, but will stay in your top soil and just have a fat turnip type form.

I would create pockets of fertility in the area: drill or dig a hole (again, if possible, my clay is pretty easy to work with in the fall/winter as it is wet, maybe yours is different), make it a foot or more deep, fill it with your manure, cover it with your topsoil in a mound form. Next spring, you can plant your melons/squashes in these mounds. Melons/squashes need a lot of space for their vines, but their root system is very local, you don't need to improve the whole area, just the places were roots are.

Now, if you have a lot of time to dig/drill and enough manure/compost/..., you can make those holes close enough so that the worms can travel from one hole to the other holes, so you will also improve the soil in-between the holes (a technique sometimes used to fertilize trees).

M