Here's why you should subsoil, meaning "rip" compacted clay ground.

[sixdogs]

Compaction is a crop stealing problem on most any clay ground. Not so much on gravel because gravel doesn't compact.

Here are some pics after I subsoiled my sweet corn ground with a subsoiler/ripper. I went 12" to 14" deep and look at the chunks of hard clay that it brought up. Imagine roots trying to grow through that. There's a five gallon bucket for comparison. Think of the water that can now run into those cracks in the ground and how soft the soil will be for the sweet corn roots to penetrate.





The compaction was caused by some tractor traffic and a fair amount of foot traffic. That's all. I used a three shank ripper but there are single shank models and 40 HP will pull one of those 12" or 14" deep. Deeper is no longer suggested because it can invert the soil layers and cause more harm than good.

 

[flusher]

Corn is an annual with fairly shallow roots so ripping a foot or so deep is fine.

Around here there are many thousands of acres of orchards (almond, walnut, pistachio, plum, mandarin orange, olive) that require ripping down to 3-4 feet to break up the hardpan so the tree roots can get established. D9 Cats with dual rippers are the usual way that's done. Historical note: Caterpillar started here in the central valley of CA in the early 1920s when the early Cat track layers were developed to break up the thick hardpan with giant rippers. Later the company moved to the Midwest to tap into the much larger field crop market.

Soil inversion is a big problem with moldboard plows. Not so much for rippers and chisels.

Good luck

 

[Kyle_in_Tex]

I have used my box blade to scrape out the soil in my garden down about a foot or so, then push it back into the pit. I have clay. Not sure what happened this year, but it was the worst year for my garden. Many seeds failed to germinate. I had added some mushroom compost last year to amend the soil too. I need more compost, but I need a bob tail load of it.
We had so much rain in late spring that all my tomato plants died from too much water.

Now, I have a fall garden full of nutsedge....

 

[sixdogs]

...

...

Soil inversion is a big problem with moldboard plows. Not so much for rippers and chisels.

As much as we all love the romance of the moldboard plow, they are pretty much gone forever. There is an occasional use to flip ground for one reason or another but plows seem to cause way more compaction and soil inversion problems than they solve. Sad to see it but it is what it is.

 

[sixdogs]

to

I have used my box blade to scrape out the soil in my garden down about a foot or so, then push it back into the pit. I have clay. Not sure what happened this year, but it was the worst year for my garden. Many seeds failed to germinate. I had added some mushroom compost last year to amend the soil too. I need more compost, but I need a bob tail load of it.
We had so much rain in late spring that all my tomato plants died from too much water.

Now, I have a fall garden full of nutsedge....

Not sure exactly what's going on but the seed should have germinated as long as there is water and seed to soil contact. Maybe the ground was scraped hard by the box blade and the seed just laid on that surface unable to make good soil contact and the surface was hard enough to dry out quickly. That would explain things. In that case I would rip the ground down a foot or more to disturb the hardpan layer. You could also amend the soil by planting crops that have thick root systems and then spading it in. Tilling is fine but tillers create hardpan in clay soil that must be broken up occasionally.

Spray nutsedge with roundup and problem solved.

On the too much water thing, ripping would also help in that the fractures in the ground allow the water a path to escape.

Finally, fertilizer is a huge help. You only add a little as the plants are starting up but more as fruit forms. Too early means all the growth will go in the leaves.

Kyle in TX--I know you know these things but others may not.

 

[smstonypoint]

I remember Clemson agronomists and soil scientists touting the value of sub-soiling in breaking up the hardpan that can develop in the the sandy soils of SC's Coastal Plain.

Steve

 

[Texasmark]

I use the Hay King brand subsoiler and follow with a disc harrow and then spike tooth, if making a seed bed, subsoiler alone if working an established hay patch.

My soil is Houston Black Clay and my Bermuda hay patch, which sends out runners for a new plant to root, loves the coulters on this machine as you get the subsoiling effect to aerate the soil with minimum surface disturbance and the coulter to cut the runners thus making a new plant or so between each ripper section. I was really surprised as I bought mine a few years ago at the JD dealer and it was only $1500 for a 4 shank, new. Built like a tank. Amazing.

 

[Dadnatron]

I have used my box blade to scrape out the soil in my garden down about a foot or so, then push it back into the pit. I have clay. Not sure what happened this year, but it was the worst year for my garden. Many seeds failed to germinate. I had added some mushroom compost last year to amend the soil too. I need more compost, but I need a bob tail load of it.
We had so much rain in late spring that all my tomato plants died from too much water.

Now, I have a fall garden full of nutsedge....

I believe your issue was exactly what you did to your topsoil. If you scraped and mixed the soil, you diluted your nutrient rich top 4" into a much larger amount of low nutrient soil. You also significantly diluted your organic matter (regardless of added mushroom compost) unless you added an immense amount and thoroughly tilled it.

You would have been better off tilling the compost into the top 4" and, if you have standing water or your plants show a shallow and wide root structure, ie shallow hard pan, ripping the garden with a straight verticle arm ripper set with depth no more than 2" below the hardpan.

It is a common though that 'deeper is better' with ripping. It is not.

There are several things which are critical in addressing ground care. We are just learning what can really be done, but as most people with tractors... we also think more is better.

This article on Subsoiling is a very good read and well worth it to anyone BEFORE they rip and BEFORE they purchase a subsoiler.

http://www.cetab.org/system/files/publications/weill_2015._guide_to_successful_subsoiling._cetab.pdf

If subsoiling isn't a real alternative, Tillage (daicon) radishes planted in the fall and left as a cover crop can make a big difference. They have a root structure which can get through most hard pan. Do that a couple years in a row and it is likely that your hard pan problems will be significantly improved, at very little expense and with the added benefit of cover crop as well as increased organic matter. And don't worry about the radishes in your garden, they will degrade into big round holes by spring.

 

[sixdogs]

I'm the OP on this and here a couple more pictures of chunks pulled up at 12" to 14". Most of these chunks are 1/4 to 1/2 or a little less than the size of a five gallon bucket. Lets see your sweet corn try to grow through that ground. I still find it hard to believe the compaction that forms in clay ground when I think not much is occurring

 

[sixdogs]

I believe your issue was exactly what you did to your topsoil. If you scraped and mixed the soil, you diluted your nutrient rich top 4" into a much larger amount of low nutrient soil. You also significantly diluted your organic matter (regardless of added mushroom compost) unless you added an immense amount and thoroughly tilled it.

You would have been better off tilling the compost into the top 4" and, if you have standing water or your plants show a shallow and wide root structure, ie shallow hard pan, ripping the garden with a straight verticle arm ripper set with depth no more than 2" below the hardpan.

It is a common though that 'deeper is better' with ripping. It is not.

There are several things which are critical in addressing ground care. We are just learning what can really be done, but as most people with tractors... we also think more is better.

This article on Subsoiling is a very good read and well worth it to anyone BEFORE they rip and BEFORE they purchase a subsoiler.

http://www.cetab.org/system/files/publications/weill_2015._guide_to_successful_subsoiling._cetab.pdf

If subsoiling isn't a real alternative, Tillage (daicon) radishes planted in the fall and left as a cover crop can make a big difference. They have a root structure which can get through most hard pan. Do that a couple years in a row and it is likely that your hard pan problems will be significantly improved, at very little expense and with the added benefit of cover crop as well as increased organic matter. And don't worry about the radishes in your garden, they will degrade into big round holes by spring.

Good advice and a great link to a subsoiling booklet. There are a couple things the booklet brings up that I forgot to mention. One is that the time to subsoil is when the soil is dry in August through the fall. Never in wet ground.

Second is that subsoiling can be done in two directions to assure the soil is loosened. Some guys will go one way the first year and then at an angle to the first ripping the second year. Some do it all in one year. Going two ways really loosens the ground.

There is mention in the booklet of 50HP per shank required but I think that can be too high of a suggestion. Maybe if two wheel drive and a lighter tractor but my 90 HP Deere 5520 with weights, radials and four wheel drive pulls three shanks @12" to 14" just fine in dry and hard ground.