I would suggest laterals at 16 feet apart.

Thanks, Wayne! I was hovering between 16 and 20. I'll probably do 16 for the wetter areas and 20 for the rest.

You asked for criticsm-

Gypsum is not going to help the drainage unless you're adding a lot of sodium chloride from the manure. Gypsum leaches out salt. Salt decrease drainage.(I'm pretty sure the type of soil you have doesn't naturally have a lot of salt in it).

It's not likely that your clay needs any more additions of rock phosphate. It's likely there is plenty of phosphorus, but it can only be accessed by your plants with a sufficient amount of organic matter in the soil, 5-10% or so.

You probably have a hardpan in your soil, which is a main cause of poor drainage. This is a compacted layer in the subsoil that prevents drainage. This can develop from tilling. The soil can be ripped to a couple of feet deep, and stop tilling. Avoid compacting the soil when it is wet.

Grow cover crops if you can.

Cover the soil with any mulch you can find.

I have no experience with that large of a garden.

We have very similar soil.

M

Since Ohio soils are not sodic gypsum will not do much of anything. Hardpan is the result of a chemical reaction in the soil that causes certain elements (Iron
Oxide and Calcium Carbonate) to bind even more tightly together so through flow is severely restricted. That often happens in soil lacking adequate levels of organic matter.
How much organic matter is in that soil? When manure is added to soils there should also be about 3 times as much vegetative waste applied to help keep the rather soluble nutrients in the manure from being washed out and to help the Soil Food Web convert them to what plants can use.
Field drainage is a science and every field needs to be assessed and drainage system designed for that field. Usually your Natural Resources Conservation Service office can help with that. How deep must the "tiles" be? What kind of slope is needed? Where is the excess water going to go? Will that outgo adversely affect someone else (illegal in most places)?

Here is a link that might be useful: Field drainage

Hi Kimmsr,

How are hardpans formed when there is an adequate level of organic material ?

M

I agree that you need guidance from someone fimiliar with local conditions. You say this is being done to generate extra income. I don't see how you will recover expense of tileing. For what it's worth I will share my experience with poor drainage. I to have land that is flat and level. Using a cheap builder's level,I located a chain of low spots ( most were only 3 to 5 inches lower than average) from front of a 5 acre plot, 950 feet to the rear where a large natural ditch runs. With my 50 hp farm tractor and middle buster,I plowed a central ditch front to back,hopscotching low spots that didn't require much deturing. I then ditched from majority of remaining low areas to the central ditch. Soil plowed from ditches was moved to low spots that didn't lend themselves to connecting with ditches. Soil was moved with a 3 point scoop and a box blade. Disturbed soil didn't erode because water flowed so slowly. A savy buyer can purchase a good used tractor and 3 emplements similar to those for $5k and it will last a life time on a small place or will resale any time over the next 5 years for what it cost.
That's an overview of how I did it. Now my experience with french drains,tile drains and dry wells. The companies I worked for spent millions on draining commercial lots then millions more maintaining the systems. The biggest problem with and sub-surface drainage is stopping up with dirt ,grass,leaves and trash.
I would think your cultivated field would fill the lines with dirt very soon.
Will you please explain what a crock is and what you mean? Your statment " I will be using a crock and pump and a surface pipe when we get heavy rain, as I can't dig deep enough to let gravity work for me."

The hardpan that was in the soil I have here was apparently broken apart by the Soil Food Web after I introduced adequate levels of organic matter into the soil. I have not found hardpan in soils that had adequate levels of organic matter.

"Some hardpans are formed by deposits in the soil that fuse and bind the soil particles. These deposits can range from dissolved silica to matrices formed from iron oxides and calcium carbonate. Others are man-made, such as hardpan formed by compaction from repeated plowing, particularly with moldboard plows, or by heavy traffic or pollution"- (Wikepedia). The OP, in other words, can inadvertently form a hardpan, even with an ideal level of organic material. Please, let this be the last time, Kimmsr. Thankyou.

M

Although often considered the same plowpan, caused by mechanical action such as plowing, and hardpan, caused by a chemical reaction in the soil, are not the same thing.

The point is, Kimmsr, the OP's clay can become poorly draining, independent of whether there is already an adequate level of organic matter in the soil, or not, via mechanical means.

You brought in the red herring about chemical reactions in the subsoil, nobody else. Don't try to defened your behavior of one more time overcomplicating a subject matter for a newcomer, and creating friction with others in this forum, with a failure at regulating a jaw that has never been quite able to match up with it's brain. M

"Soil compaction is a common and constant problem
on most farms that till the soil."... "If a hard pan does not exist, equipment traffic generally will create one."

Ohio State Universlity