Help converting clay-y horse pasture to vegetable and plant sustaining "garden"

Hi folks, newbie here. This is my first year at our home in Colorado and I'm working on getting some vegetable and plants in the ground. The area I'm using has had horses on it for 40 years. It's hard packed clay soil. Almost nothing growing on it. I did one of the store bought soil tests and nitrogen is very high and ph is also high, 8+. I have access to fir sawdust. Would this help level out the N and add balance the ph a little? Other suggestions? P and K seemed about normal. Thanks!

First, Welcome to Permies!

Two immediate concerns to address. Compacted soil does not breath. No air means no micro-organisms, which leads to dead soil. You have to uncompact the ground. One can do this mechanically with a tractor or by growing deep rooted plants that will open up the soil. Each has its obvious benefits and drawbacks. Next, clay soil is usually low in organic matter. Organic matter is what keeps the clay from turning into a hard substance between rains. You will either need to grow mulch and recycle it back into the soil; or bring in organic mulch/material to build up the soil profile.

For mechanical aeration, look at a sub-soiler or yeoman's plow. Although a chisel point plow may have all the depth needed for what you can get out of your soil for many years. For natural aeration, look at plants like alfalfa, radishes, mullein, comfrey, or anything that goes deep and opens root channels into the clay. Clay usually has sufficient nutrients, but requires air and water to circulate below the surface. Mechanical methods have a higher cost, but a quicker return. Organic conditions the soil more, but take many seasons to get results. There is no practical reason not to use both.

Organic matter in the soil is necessary for the microbiology necessary for healthy soil. The micro-organisms are food for the worms. The worms break down the minerals and fertilize the roots of your plants. You don't raise vegetables, you feed microbes. Any organic matter will do. Grass clippings, cardboard, straw, wood chips, newspaper, food waste, manure. The options are whatever one can find. Sheet it. Mulch it. Keep it moist and airy, and let nature do its work. Just don't let it turn back into a brick.

hau, Lindsey,

Let me delve a little deeper on the same lines of Jack's suggestions.

First thing to do is de-compaction of the soil. This can be done fast with the suggested tractor and sub-soiler.
IF that is not available or practical the next best method to lift the soil and get air in would be a broad fork, this will take more time and it is a manual method, but you will get into physical shape while working the soil.
IF that method is not acceptable or doable, then top dressing with composted manures and regular, finished compost, then planting deep root crops such as Daikon Radish is the place to start.

After de-compaction would come a layer of organics, compost or composted manures followed by deep root plants, such as daikon radish. This planting is going to add more organic material.
As you can tell, the process will take about one year to get through and have soil suitable for vegetable crops. Building soil back to health takes time, even with short cuts.

Now let me give you a suggestion plan of attack for getting this pasture ready to plant your crops in, it is a one year plan.
1. De-compact soil spread composted manures and wood chips over the area
2. Plant deep root plants for chop and drop in fall, plant nitrogen fixers for chop and composting away from area (nitrogen fixers suck up a lot of N and store it in themselves, so chopping and removing will reduce the amount of N, in the soil to healthy level).
3. Spread one or all of these; pine straw, pine wood chips, lowland peatmoss, western cedar chips. The plan is to get some organic, acidic items into the soil to lower the pH.
4. In the fall, chop and drop the deep root plants, leaving the roots in place to decompose, thus adding all that organic material to the soil naturally.
5. Take multiple samples from a grid layout and submit for new analysis to see where you are now in the rejuvenation process.
At this point, you should be able to plant your crops, you may find it advantageous to amend exactly where your plants/seeds are placed.

On our farm, we always add amendments when we set the transplants, this way we are using less materials than broad amendment. It has the benefit of reducing costs on the front end,
and allows us, over time, to get specific areas rejuvenated and since we alternate our garden areas, we will end up with complete rejuvenation.

You've be able to get some hardy squash to grow with little effort. I certainly have never had a problem with squash in our compacted clay soil. I bought a bunch of nitro radish from greencoverseed.com and I'm going to do that this fall to help aerate and add organic material.

If I were you I'd start the process everyone else has suggested this year while reserving a small area that you won't mind hand working to use this year for veg. Then expand as you have the time, energy and soil.

Wow thanks so much for these helpful suggestions. For some reason I wasn't getting notifications so I was thrilled to see all your replies. I'll give these a shot. Thanks for the warm welcome!