working with clay soil

[iron]

i'm planning to add some fill to my yard to get it a bit more level. i got 12 yards dropped off for free from craigslist, but as i was shoveling, i noticed it was quite clayey. there are intermittent baseball-to-basketball sized clumps. the rest of the soil is probably clay, but not bonded as well (yet?).

anyway, my concern is that if i spread out the 12 yards, that now i will have a water resistant barrier. i'd like to amend the soil, but on the cheap. i've read that in order to do it well, you basically need >50% sand added to it. that's not happening (too much $). i also read that you can use gypsum, so that got me thinking: what if i use demo'd asphalt chunks (2" diameter max)? i will be demoing a small bball court in my yard in a few weeks. i can recycle it for a reasonable price, but if i can just use as fill, that would be way easier.

do you think this will work?

likewise, i can probably get free woodchips delivered too. would those help? ultimately, the top layer will be topsoil from a nearby supplier, so the grass should grow well. i just don't want a soggy yard for 6 months of rainy season.

 

[sportbikerider78]

Rent one of these from Sunbelt for the weekend, when the weather has been dry. You can grind up the fill you just got with your existing topsoil and smooth it all out. I fixed 12" ruts in my backyard and smoothed it all out on a saturday. A very easy saturday.
<$300 for a weekend rental.

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[semipro]

Investigate what adding lime does to clay soils. It's a common treatment and relatively cheap/easy to do.

 

[Highbeam]

Gypsum is lime, asphalt is neither

 

[Ashful]

No on the asphalt. Not my area of expertise, but read up on peat moss.

Wood chips will take an awful lot of nitrogen out of the soil, for several years, which won’t do any favors for your lawn.

 

[begreen]

Gypsum is lime, asphalt is neither

Lime is calcium carbonate (CaCO3), Gypsum is calcium sulfate (CaSO4)

 

[peakbagger]

I agree that wood chips or sawdust is bad idea but biochar is probably a good option as the nitrogen has been put back into the carbon.

 

[Highbeam]

Lime is calcium carbonate (CaCO3), Gypsum is calcium sulfate (CaSO4)

Same enough for the application. Like burning alder or maple. Chlorine for water treatment comes with several carriers too but they all result in free chlorine.

So if you’re going to write all that out then how about telling us what difference the sulfur/carbon makes?

Asphalt is fine as a filler but doesn’t solve the clay issue or help your grass.

In the old days, if you ticked off a contractor he would dump a sopping wet truckload of clay in your driveway.

 

[begreen]

They react differently. One notable difference is that lime will change the soil pH. Gypsum does not, it's a neutral salt. It also provides available sulfur to the plants which is beneficial. Another specific difference can be in the type of lime. Pure lime (Ag lime) is calcium carbonate, but dolomite lime is about 50% magnesium carbonite. In soils that already have a high magnesium content (like our glacial till) adding a lot of dolomite lime can turn it toxic.

I learned about this stuff with a test garden project I have been running for the past 3 years. It had clay soil that needed remediation. The soil supported only the strongest weeds and presented a real challenge to turn around. The most dramatic change that occurred was with the addition of compost to the soil. If possible I would try to locate a source of cheap compost to mix in with the clay soil for a quick change in it's permeability. This might be a load of composted manure from a local farm, someones old grass or leaf clipping pipe, etc.. The change I saw when I first added compost to the clay soil in the test garden was nothing short of dramatic. Water no longer sat on top of the beds after a rain.

 

[Ashful]

but dolomite lime is about 50% magnesium carbonite. In soils that already have a high magnesium content (like our glacial till) adding a lot of dolomite lime can turn it toxic.

Uh oh... Dolomitic lime is exactly what my turf company gives me when I need to adjust soil pH, but I'm already high on Magnesium, at 303 - 327 m3-ppm.

 

[begreen]

Saw this happen at a local farm too. It's good you have tested first. But i think you may be ok. Our test garden is at 343 in one location and 399 ppm at the other. Optimal range is 50-120 according to our test lab (UMass Amherst).

I'm not sure how much this affects lawn grass. It's important with vegetable gardening. Too much magnesium contributes to a deficiency in calcium which can limit root and fruit production. It can also affects the potassium balance which can bring about a yellowing of leaves and poor water uptake.

 

[jeanw]

Lime is calcium carbonate (CaCO3), Gypsum is calcium sulfate (CaSO4)

so which one to use to break up clay other than adding organic matter. but gardening I will do no till. esp if you have good ground.
supposedly acc to some the Uv range has changed and its killing the microbes in the soil. Heard this yesterday On USA prepares I believe on RBN. hum. remember the episode TZ "to serve Man". we re prob being terra farmed... those who laugh last. y'all just don't want to believe

well what ever. I should be outside watering. but got so many dilemmas thanks y'all

 

[Ashful]

Saw this happen at a local farm too. It's good you have tested first. But i think you may be ok. Our test garden is at 343 in one location and 399 ppm at the other. Optimal range is 50-120 according to our test lab (UMass Amherst).

I'm not sure how much this affects lawn grass. It's important with vegetable gardening. Too much magnesium contributes to a deficiency in calcium which can limit root and fruit production. It can also affects the potassium balance which can bring about a yellowing of leaves and poor water uptake.

For established cool season turf (tall fescue, here), the recommended range is much higher, 170-320 m3-ppm. But I'm always right near the top of that range.

I get a yearly test, multiple samples across 3 acres of lawn, and adjust the yearly fertilizer plan to suit. Keeping a golf-course quality lawn is not that hard, with the right data and a plan. I use much less fertilizer per acre now, than I did a decade ago, trying to guess what the lawn really needed.

Unfortunately, I'm not as savvy as you, to know the exact effect of each nutrient. But I have a turf specialist who helps to develop my yearly plan, it's just my job to follow it.

 

[iron]

thanks all. sounds like compost is the way to go if i can source it free. sadly, there's a guy 10 miles from my house that would drop off 40 yards for free (nothing less), but that's too much for me and his semi truck wouldn't work in the driveway anyway.

 

[iron]

They react differently. One notable difference is that lime will change the soil pH. Gypsum does not, it's a neutral salt. It also provides available sulfur to the plants which is beneficial. Another specific difference can be in the type of lime. Pure lime (Ag lime) is calcium carbonate, but dolomite lime is about 50% magnesium carbonite. In soils that already have a high magnesium content (like our glacial till) adding a lot of dolomite lime can turn it toxic.

I learned about this stuff with a test garden project I have been running for the past 3 years. It had clay soil that needed remediation. The soil supported only the strongest weeds and presented a real challenge to turn around. The most dramatic change that occurred was with the addition of compost to the soil. If possible I would try to locate a source of cheap compost to mix in with the clay soil for a quick change in it's permeability. This might be a load of composted manure from a local farm, someones old grass or leaf clipping pipe, etc.. The change I saw when I first added compost to the clay soil in the test garden was nothing short of dramatic. Water no longer sat on top of the beds after a rain.

View attachment 228318

begreen: would you recommend the "screened comp mulch" on page two of this link?
(broken link removed)

if i have 12 yards of clayey soil, would you recommend 10 yards of compost?

 

[begreen]

begreen: would you recommend the "screened comp mulch" on page two of this link?
(broken link removed)

if i have 12 yards of clayey soil, would you recommend 10 yards of compost?

A 50/50 blend of the soil with compost would be serious overkill. I mixed about 44 cu yds of clay soil with 7 cu yds of compost and it made a major difference. This was for gardening, not just lawn fill. 2-3 cu yds of compost well-mixed or evenly tilled in with your 12 cu yds of clayey soil should be fine unless the soil is heavy clay. If so maybe 4 yds..

 

[Marshy]

Where might I find info about testing my soil?

 

[begreen]

http://ag.umass.edu/services/soil-plant-nutrient-testing-laboratory

 

[Ashful]

http://ag.umass.edu/services/soil-plant-nutrient-testing-laboratory

That, or any place that sells lawn products probably has a contract with a company that does this. The folks I buy my seed and fertilizer from do mine for free, since I buy a lot of product, but I think it normally costs around $15 per sample.

Unless you have specific problem spots you want to isolate, best practice is to take a half dozen small samples around the yard, mix them together, and use that as a single sample. $15 will tell you more than you will ever guess on your own.

The sample bag probably only holds 3 fl.oz., so we’re talking a few teaspoons from around the yard to make up a full sample. Google “how to collect soil sample” for pretty simple instructions. I use a bulb planter to do mine: pull a plug, shake a little dirt off into a quart yogurt container, stick the plug back in the hole. Do this in a dozen different spots, mix up the contents of the yogurt container, and pour some into the sample bag.

 

[begreen]

Many universities offer comprehensive soil testing. I like UMass because of their testing methods and good track record, but I am no expert. Before starting our test garden project we pulled together a panel of scientists. They went over many more variables primarily focused on the health of the soil. The agricultural philosophy is changing from feeding the plant to feeding the soil, which is a complex and very alive entity. It was this panel that recommended UMass Amherst for testing.

While there are some similarities, turf management and food garden management are not exactly the same. Testing methods may vary as well as the report advisement. It's good to let the testing company know which is being tested. Some testers will have a place on the form to indicate the purpose of the testing.

 

[Ashful]

Many universities offer comprehensive soil testing. I like UMass because of their testing methods and good track record, but I am no expert. Before starting our test garden project we pulled together a panel of scientists. They went over many more variables primarily focused on the health of the soil. The agricultural philosophy is changing from feeding the plant to feeding the soil, which is a complex and very alive entity. It was this panel that recommended UMass Amherst for testing.

While there are some similarities, turf management and food garden management are not exactly the same. Testing methods may vary as well as the report advisement. It's good to let the testing company know which is being tested. Some testers will have a place on the form to indicate the purpose of the testing.

If testing for turf, they usually want to know age of lawn (i.e. less than 3 years, or “established turf”), and type of grass (i.e. cool season or warm season, if not species).

No panel of scientists, here. But I do have a lot of folks stop and comment on the nice lawn, as well as neighbors who rib me for making them look bad.

 

[iron]

A 50/50 blend of the soil with compost would be serious overkill. I mixed about 44 cu yds of clay soil with 7 cu yds of compost and it made a major difference. This was for gardening, not just lawn fill. 2-3 cu yds of compost well-mixed or evenly tilled in with your 12 cu yds of clayey soil should be fine unless the soil is heavy clay. If so maybe 4 yds..

was your compost pure compost (straight from the farm), or was it a blend that you'd get from a soil yard?

 

[begreen]

What is 'pure' compost? Farm compost is often manure compost, but that doesn't make it pure.

The compost we used is straight from the compost maker in Tacoma. It's primarily composted yard waste.

 

[Highbeam]

was your compost pure compost (straight from the farm), or was it a blend that you'd get from a soil yard?

Good point. You can buy “soil” now that is often referred to as a three (or more) way mix of things that the yard had. Our local manufactured soil is sand, sawdust, and compost.

Compost for this context is 100% organics and not mineral soil. Think rotten bark mulch, leaves, or other ground up vegetation. Manure is vegetation ground up by animals.

Is that what you used bg?

 

[Ashful]

Good point. You can buy “soil” now that is often referred to as a three (or more) way mix of things that the yard had. Our local manufactured soil is sand, sawdust, and compost.

Compost for this context is 100% organics and not mineral soil. Think rotten bark mulch, leaves, or other ground up vegetation. Manure is vegetation ground up by animals.

Is that what you used bg?

Keep in mind that some of these things, esp. wood products like sawdust or decomposing mulch, leach much of the nitrogen out of the soil, that you want to save for the stuff you’re growing. Manure and peat are better soil modifiers, than sawdust or mulch.