Let's Talk About Clay Soil, Again.

[Kenyadenola]

I have clay soil and it's been amended over the years, but I have noticed this tear that it seemed to compact even without me walking on it. Because of this compaction it is holding water even more so than normal.

Most of my plants are doing okay after overcoming some deficiencies, but a few in another plot I have noticed seem to be suffering from overwatering even though they haven't been watered in a while. I use a moisture meter and it's been hitting 10 for a while now so I dug a bit. While I can tell it's the color of moist soil, it doesn't really feel wet. It will form a ball, but it will also crumble easily, you have to clamp your hand really tightly to get it to form a ball, and some if it is really crumbly. It seems somewhat moist, but not wet like I would expect a "10" to be. The soil was also incredibly packed, so I know the roots are having some issues.

Now here comes the question, is there anyway to loosen the soil and get it to dry out a bit without damaging the roots to badly? I know a lot of you would say "just let it dry out", but it's been this way for about a month and a half, and two plants in particular are having issues. Others in the area seem to be thriving, oddly, but Opalka, Purple Russian and Orange Banana are not thriving. Orange Banana in particular is starting to struggle. If there are any solutions, I am open, I just hope there is something I can do to help them.

Thanks in advance!

Kenya

[feldon30]

I think if you try to improve clay soil without raising the level of soil, you end up with a bowl that water stays in.

I did a raised bed 10" high and didn't put a bottom. I figure all the organic material I am adding on top will improve the soil but I'm still up and out of the mudpit.

[dcarch]

Originally Posted by Kenyadenola

I have clay soil and it's been amended over the years, but I have noticed this tear that it seemed to compact even without me walking on it. Because of this compaction it is holding water even more so than normal.

Kenya

What have you done to amend your soil?

dcarch

[Suze]

Okay, I read through your post, and am a bit confused. Here's why. First you're saying that the soil seems to be compacted and holding water; even rates a 10 on the moisture meter. Then you mention it being crumbly.

I guess my question is how are you coming to the conclusion that the soil is compacted as you say it crumbles easily? Could it be that you've done a good job amending and that your soil is 'shrinking' (to be eventually expected when organic matter is added, it breaks down), and has dropped in level instead?

Help me to understand.

[kwselke]

I do not believe there is anything that can be done to your clay soil that will help out currently growing crops. Between crops you can turn in additional humus and you need to expect that the turned area will contract over time. Over a period of years turning and amending will yield great results.

[Kenyadenola]

Wow, you guy's are a speedy bunch!!! Thank you!!

I have been growing tomatoes for a while now and every year I get better, but knowing more, means that now what I use to think was just old tomato age, I now know is disease, or something else. I didn't used to know what yields to expect, now that I know, I can't just say they are being tempermental. Ignorance was bliss!

Well, first off, the plans to raise the beds at least a foot have been laid out since the begining of the season, so I am really looking forward to next year. I look at my one raised bed, and shake my head in disgust at the others.

As for amending, I have added lot's of the following for the past five years, chicken poop, humic acid ore, worm castings, home compost. This year I added greendsand, kelp meal, bone meal. The soil is much better than it used to be, but I forgot to do my usual pH test, and thusly my pH is about a 7.5. That will also get corrected before next year.

As for it rating a "10" but being crumbly yet compact. I did not account for the settling of the OM, which makes since and I should have thought about that, but I could tell when I dug that it was compacted. Besides that fact that is somewhat rocky(the big rocks were taken out so all that is left is little rocks, which isn't as bad as it seems), when I dug the whole I could see the sides, and they are pretty tight. It was not easy to dig at all, it wasn't rock hard which I atttribute to a layer of compst on top, with a 6 inch layer of straw on top of that, but it was not soft. The sides of the hole don't cave in and it doesn't look like there are a whole lot of airspaces. Whereas when I dig a whole in my raised bed which had sandy loam, it is hard to dig deep without the sides caving in. As for the crumbly, that is the how the dirt is once you get it out of the whole and poke at it. It doesn't clump together as easily as it once would have, which is good, but if you hold a lump of it and close your hand tightly it will form a little ball of clay. Now if it is a small ball, you can break it easily with your finger, but if it is a bigger ball, it takes a bit more work to break it up.

So what I think probably happened is the OM settled and shrunk, but due to it being clay, instead of just shrinking and settling, it shrunk and clung together tightly. So now you have the OM which holds moisture and the clay which really holds moisture working together. So now I have learned that I really should have added WAY MORE OM than I did. Lesson learned, unfortunatley it seems that there is no way to help the current crop, which makes me sad because I don't want to watch my plants struggle, but I don't have the heart to pull them up either.

Next year the plan is to raise the beds, there are three, one is 100 sq. ft, the other is 60 sq. ft. and the third is about 50 sq. ft. We will fill the back of the Scout(like a Chevy Blazer, but better IMHO) with free mushroom compost since we are close to Morgan Hill, the mushroom capital, and you can't beat free. I figure we will have to fill the Scout probably 5 times if not more in order to increase the level of OM and raise the bed and then to that I will ad the usual poop and stuff. Hopefully this will work, if there are any other ideas, please suggesst away, and if anyone can come up with a way to help this years crop, I'm still listeneing.

Kenya

[landarc]

I am a fan of organic compost and mushroom compost can do wonders. However, it is short lived, as are most composts, in terms of adjusting the overall texture of soil. Clay soils, in particular, can be problematic for long term texture improvement. We generally look at adding 4 to 6 inches of organic amendment to 18" of soil when we are working with establishing a sports field in the SF Bay Area. Essentially, this amount to adding 30% approx. by volume of a soil lightening substance. in extreme cases, there is always ag. gypsum to add also. Breaking up the soil is also a good practice every year, double digging being a well advised practice.

Raised beds filled with a high quality topsoil are, of course, a great way to go. The thing to remember is with clay, the amount of material necessary to permanently adjsut soil from a USDA clay classification to a more desirable loam or clay/loam classification is substantial. Adding 50% sand by volume alone will simply make the clay adhere even better than clay alone. I recall that it is somewhere around a 70% coarse/20% loan/10% clay ratio.

In some cases, punching holes into the soil, or cutting slits, may help introduce air to the soil, but, this also damages roots and can aid in developing fissures as the soil drys. The fact that clay balls up can be deceptive as there is more to what causes clay to adhere than simply moisture, and certain clays hold more moisture than others. In my experience in ornamental landscape moisture sensors are notoriously inaccurate in clay soil conditions in terms of determining free and available water versus overall moisture content.

[dcarch]

My suggestion is adding Perlite.

Try it out in a small area first.

dcarch

[matereater]

Do you think using a pitchfork to help loosen the soil would help or might be too destructive to the existing roots ?

[Kenyadenola]

The idea of the moisture meter beinig inaccurate started me thinking and doing more research. I'm looking at my plants and thinking that they are having problems because they are to wet, but in actuality, they could not be getting enought water.

I just read that when clay starrts to dry out, the moisture that it is retaining can be unavailable to the roots of the plants. So while the meter is reading that the soil is saturated, it could be because the clay particles are packed so tight, it is giving it that reading, but the moisture is actually unavailable to the plant, so in theory, the plant is not receiving any water.

The plants are wilting a bit, but the parts that are wilting are the yellow leaves, so I figured they are wilting due to dying, and the fact that they have the wispy foliage, it's hard to tell in general.

Against all my better judgement, I am going to give one plant some water today, and see what it does, if it seems to respond, I will water the others.

Wish me luck!!

[Kenyadenola]

Well, another day of gardening has gone by, and I would like to say that I think Landarc may have been on to something about the moisture meetings giving inaccurate readings in clay soil.

For the last week I have been looking at my cucumbers which are behind a patch of tomatoes. The leaves are usually wilting, and I kept telling myself that since the sun is shining on them and it is warm, that is why they look wilty, and since the moisture meter said the soil was wet, I didn't water. Even thought that voice in my head said to make sure the cucs get enough water so they are not bitter. They usually perk up a bit in the evening, so I wasn't terribly worried.

Today I look at them, and as usual they are kinda wilty, but today I decided to give them water and see what they do. Well, don't you know they perked up in about 15 min. and stayed that way all day!!

So that tells me that the moisture meter was wrong, and perhaps the cause of may toms looking stressed was because they were not getting enough water instead of the opposite. It seems that since the clay particles pack together so tightly, they give the reading of being wet, but there is actually not enough water in the soil for the plants. I was using the moisture meter and reading the plants all wrong.

So yes, there is some compaction due to the shrinkage of the OM, and that is probably not the greatest thing for the toms, but my reliance on the moisture meter was doing them much more harm

If it hadn't been for reading Landarc's post this morning, I may not have put it all together, so thank you very much.

Now, if I would just stop paying attention to the plants, I could stop finding things to improve and thereforestop bugging my husband with all my plans for improvement!!

[landarc]

You're welcome.

The real causes and answers are somewhat more complicated, and relatively unimportant if things are going well. Glad I could help.

[Worth1]

My Hero!

Worth

[landarc]

dcarch,
we used to use perlite as a soil additive to lighten the overall texture of the soil. It is exactly what it is designed for. It is an excellent long term adjustment process to make a heavy (clay) soil lighter. However, it is not cheap and it takes a lot of perlite to successfully change the soil from clay to loam in texture.

It does offer the added benefit of being slightly porous and adding to the potential available moisture profile. It is certainly a viable option.

[LoreD]

One of the problems in clay soils is not just the too little or too much water, it is that oxygen is not getting to roots. Sometimes even well watered plants in clay soil are deficient in oxygen at the root level.

The Australians recommended watering with a form superoxygenated water. All that is necessary is buy a large bottle of hydrogen peroxide and add several tablespoons per half-gallon water. Some sites recommend a higher concentration, but you could start with that.

The peroxide H2O2 adds an extra oxygen molecule to the water. It also clears the chlorine from tap water. The reason that rain water is better for plants is because the ozone creates peroxide in the rain which makes rainwater oxygentated.

The Australian study recorded up to 85% increase in plant production by watering with superoxygenated water.

I too am gardening in rock hard clay soil and I have noticed the difference when I have watered with a little oxygen boost. They grow much faster and are much more productive.

I'll go find the link for you and post it later.

LoreD