How to break up rock-hard soil?

[TheWaterbug]

My property has an old paddock that's no longer used for horses. I rented a rototiller and churned up the top few inches of soil, but it's like concrete below that layer.

If I swing a pickaxe through it, I can get through ~6-8 inches of compacted sandy stuff, and then there's heavy black clay underneath that. The sandy stuff will break apart in my hands, but it's like breaking up sandstone. I'm 215 lbs, and I can't get through it with just a shovel; I actually need the pickaxe.

I dug a hole about a foot deep and filled it with water. An hour later the water still hadn't drained away.

I was sorta successful planting pumpkins in the paddock last year, but after we harvested all the pumpkins I dug out a few vines, and I saw that they really hadn't rooted below the few inches of topsoil.

Any suggestions on how to break this up? Equipment I can rent for a day? Something to plant in the winter that would actually penetrate? Explosives? It would take me a year to break it all up with the pickaxe!

[Kisal]

I think you have what is called hardpan. You can correct it, but it's going to be a big job, I think. You have to dig through it. The tool called a broadfork is designed for this purpose, but you can use a mattock or pickax, if you prefer. If you have or can rent or borrow a tractor, you can use a chisel plow to break through hardpan.

Once you get it all broken up, you have to add a lot of organic material, such as compost and well-rotted manure. Personally, I would add a bunch of gypsum, too. Check the pH and add whatever is necessary to correct it. You'll probably have to amend it annually, to keep it from reforming into hardpan.

Or, you can build raised beds in the paddock. I would make them a couple feet deep, and drill holes all around the bottom edges, to make sure there's sufficient drainage. JMO.

[TheWaterbug]

Ah! This is confirmation that I've picked the right forum to join. Thanks for the info; I've learned three new words!

I might pick up a broadfork for a smaller area that I'm doing this weekend, and I'll have to look into renting a chisel plow next year to dig up the whole field.

For testing the soil, are kits like this worth $15? Or am I better off getting it tested professionally?

Thanks!

[SOB]

Personally, I would toss down a bunch of organic matter and gypsum then build a raised bed (just like Kisal stated).

I would locate your county extension office and they will typically take your soil samples and test them for you. I would rather pay them then buy a kit and put the chemistry into my hands!

[Kisal]

For testing the soil, are kits like this worth $15? Or am I better off getting it tested professionally?

You might want to do it both ways, just for fun. Soil test kits are readily available at most garden supply stores. I haven't really found one I liked a lot or thoroughly trusted, though. To get a real answer that you can depend on, you can't beat a professional test.

If you have an Extension Service office near you, they used to perform soil tests for free. I'm sure they charge for the service now. If they don't actually do the tests themselves, they can refer you to a place that does. The Extension Service is affiliated with universities across the country, and offer a wide variety of services and assistance to members of the public.

The Internet has placed an enormous amount of information at our fingertips, but the Extension Service can help you understand the details of your exact area, such as soil composition and geology, insect pests and helpers, weather patterns, and a lot of other stuff.

[applestar]

Your choice of plants this year matters too. I found sunflowers and corn are pretty good at penetrating clay soil. Alfalfa as cover crop is said to grow deep roots. Potatoes are also known for their ability to function as pioneer crop as are deep rooted mustards and radishes.

Pigweed/amaranth is another.

In all cases, what you want to do is to leave their roots in the ground as organic matter rather than uprooting them at the end of the season.

Building compost piles on-site also helps.

[hit or miss]

Plant it to sunflowers this year. They have a jackhammer like taproot that really penetrates soil and breaks it up. I would do some hard work this year to get some of it planted and let the sunflowers do the rest!

[TheWaterbug]

Good news! I just happen to be putting in some corn and sunflowers right now. I'm only putting them in one section of the field, so we'll see how they do after the season has ended. I've already committed most of the rest of the field to pumpkins.

I had no idea that broadforks were so expensive. The good ones appear to be nearly $200. After watching some of those videos I'm skeptical as to whether I'll be able to get through my sandstone with them. If these were $40 at Home Depot I'd just try one out, but for $200 I need to consider carefully and make sure I get the right one.

Valley Oak makes one with a gusset to reinforce each tine. Anyone used one of these?

And these folks make one with replaceable tines..

[applestar]

I imagine $40 HD version would end up with bent tines or snapped handles.

... That said, I still haven't bought one-- even though it's on the wish list along with things like pressure canner, chipper shredder, and greenhouse -- and because the area I work are individually pretty small, though they add up o a fair amount of space altogether.

[cynthia_h]

Broadforks are a one-time, lifetime purchase. Johnny's Selected Seeds in Maine developed their models in consultation with Eliot Coleman; Bountiful Gardens in Willits, California, carries those developed by Jon Jeavons.

NOTE on the Jeavons U-forks: each is custom-made for the gardener. For those who follow Jeavons' double-digging guidelines to the letter, the first double-digging prepares the ground 24" deep; subsequent double-digs (which the U-bar can be used for) are only needed to 18", b/c the subsurface re-compacts more slowly than the upper surface (pp. 11-14 or so of How to Grow More Vegetables, by Jon Jeavons). His book is a complete book for new and experienced gardeners, providing sample layouts for Year 1, Year 2, and Year 3, as well as how much to plant for X pounds of harvest.

For gardening in California, I also strongly recommend Sunset's Western Garden Book, especially for its climate-zone maps, which are very finely drawn, with 29 climate zones in the western states and provinces versus only 11 USDA Hardiness Zones in all of North America. (My personal copy is the 7th ed., not the most recent 8th.)

You're at an exciting moment in your gardening life! Congratulations!

Cynthia H.
Sunset Zone 17, USDA Zone 9

[gooberfarmer]

Waterbug-
If the soil is as hard as you say it is, I'm afraid even a broadfork won't be stout enough. In Eastern New Mexico we have soil called caliche which is just as tough as the stuff you describe. On parts of my acreage I'll either have to build raised beds or just give up. Even heavy duty farm equipment can't break through the stuff.

[TheWaterbug]

Waterbug-
If the soil is as hard as you say it is, I'm afraid even a broadfork won't be stout enough.

It is in some places, but not everywhere. I'm guessing that the compaction is due to 50 years of horse hooves pounding on it, and it's worst right in the middle of the field/paddock.

At the edges it's somewhat more reasonable. I dug out a furrow near one edge with my pickaxe this morning, and I sorta got the feeling that a broadfork might work in this area.

I found this scary-looking broadfork for $250, and the blade-like construction looks like it might be more resistant to bending than a tine with a round cross-section. Here's another bladed design for $229 (+S/H). Pricewise, I'm moving in the wrong direction!

But I'd be OK with spending $250 if it works and is durable.

If I can get through the sandy layer I'd be happy. I'm not too optimistic about the clay layer that's beneath it all, but that's nearly a foot down, so it's not a disaster if I have to just live with it. It's not just clayey; it's actually clay. I feels like the brick of potters clay that I have in a plastic bag in the garage, but drier and harder.

[applestar]

I would definitely consider cover cropping the areas you won't have worked this year.

You may want to forego the conventional wussy cover crops sold for the purpose to grow in cultivated fields, and look at the weeds that are actually setting down roots and managing to grow in the clay hardpan. They are the natures pioneers and recovery crew for devastated areas. Left to themselves, the weeds will forge the way for the next team, and they in turn for the next until someday, the entire area would become a forest.... But we're getting ahead of ourselves. We just want the first phase crew to break up the clay soil and add organic matter.

[cynthia_h]

Waterbug-
If the soil is as hard as you say it is, I'm afraid even a broadfork won't be stout enough.

It is in some places, but not everywhere. I'm guessing that the compaction is due to 50 years of horse hooves pounding on it, and it's worst right in the middle of the field/paddock.

At the edges it's somewhat more reasonable. I dug out a furrow near one edge with my pickaxe this morning, and I sorta got the feeling that a broadfork might work in this area.

I found this scary-looking broadfork for $250, and the blade-like construction looks like it might be more resistant to bending than a tine with a round cross-section. Here's another bladed design for $229 (+S/H). Pricewise, I'm moving in the wrong direction!

But I'd be OK with spending $250 if it works and is durable.

The ground you're dealing with is, unfortunately, very common in California: adobe clay. The stuff the missions and Spanish colonial buildings were made of. The buildings that have weathered two and a half centuries of storms and earthquakes. Pretty durable stuff. People (like me) who have moved here from Georgia's famous "red clay" have found the adobe to be an entirely different--and much more difficult--clay. It may be like the New Mexico caliche; I haven't fought with caliche, so can't give a personal comparison.

Now that you know what you're up against with the adobe, consider the design of all the broadforks you've looked at.

1) Personally, I would remove from consideration *any* broadfork I could not stand on, like the "deep spader" you found. The broadfork/U-bar is not meant to be an upper-body workout device. Women can and do regularly break ground with this tool, and it's not because of our superior upper-body strength relative to men; it's because we can exert *all* of our body strength/weight on this tool by standing on the crossbar safely and in an ergonomically effective way.

The strength and width of the crossbar, into which the tines are set, are critical for this purpose. Consider both how robust the crossbar is and how wide the tool is. 14", for example, wouldn't work for me, as my personal "cross-section" in the hips is (shall we say?) more than 14". I wouldn't be able to stand on such a narrow crossbar in a safe *or* effective manner. Only a very slender person could stand on a 14" crossbar and be able to move his/her arms as well. A broadfork/U-bar with a crossbar at least 18" or 19" wide and preferably wider would be great; I could stand on these quite sturdily and exert my weight very effectively while keeping a good arm position.

2) The length of the poles + tines is important, especially for tall (> 5'6") individuals. Some of the broadforks are 48" from the ground to the end of the handles (poles). That sounds terrific for me, but I'm 5'4". For my DH, who's 6'1", it would be a particularly difficult form of torture; he would have to stand on the broadfork in a very cramped, bent-over position. Not safe for him, and certainly not healthy for his back/shoulders or effective in breaking ground via use of his body weight.

Some broadforks come with longer poles, and the length of the tines varies from maker to maker, so measure yourself and estimate what total length of broadfork would be comfortable for you (and your gardening partner, if you have one) to use. Also read the makers' descriptions carefully; some refer to the length of the poles alone; others refer to the length of the poles + tines.

3) The last factor I recommend looking at for ergonomic/ground-breaking reasons is the number and strength of the tines. Some of the broadforks have widely spaced tines, approx. 5" apart, while others are much closer together, approx. 3". How finely do you need your ground broken up? Maybe you'd like to approach this project in two phases: this year, for the "cooperative" soil, and then next year--after the deep-rooted plants have done their work--for the very compacted center soil.

I'm pleased to see that the market has expanded in the past two or three years so that there are many choices available. Unfortunately, it also makes decision-making more difficult! Just read what all the websites have to say, and make liberal use of toll-free phone numbers and other interactive methods the makers have available to inform you about their products. At least one of the makers (Johnnys) has videos and instruction sheets on the website to assist in understanding how a broadfork/U-bar works; this may help in decision-making as well.

Happy gardening!

Cynthia

[Gary350]

The last 2 places I have lived the soil is rock hard when it is dry. The best way to break it up is catch it in the spring when it is drying out. If you till it too soon you bet mud balls that dry hard like gravel. You just have watch the soil and try to till it a little as it is getting dryer. The the moisture is right the soil tills easy the it crumbles up real nice. Once you get it tilled spread about 4" of peat moss over the soil and till it again about 3 times. If you can get some free scrap sheet rock from a construction site put lots of sheet rock in the soil gypsum and the organic material will keep the soil from getting hard again. Tennessee State University did some research on adding gypsum to the soil it has increased their crop production about 3 times just by adding gypsum. You need to do a web search and read what they did I don't recall how much gypsum they added.