Plowing depth

[oosik]

I just read the thread posted by Marveltone and this raised a question. How does a person determine how deep to plow? I know there are limitations based upon the implement/tractor but there must be certain observable soil conditions that dictate plowing depth.

 

[wolftree]

I am assuming you are speaking of a moldboard plow. There are many variables, but a good place to start is one half of one plows width. A 12 inch set of plows then would be set to plow 6 inches deep measured at the furrow edge/lip on the landside. A 14 inch set of plows is set at 7 inches depth.

This will give a nice rollover of the soil.

 

[oosik]

Thanks Wolftree,
Yes, I have a 16" single bottom moldboard plow. I can see that in some circumstances I've gone a tad deep.

 

[wolftree]

Draft control, position stops on the three point and rear gauge wheels on the plow all are aids in maintaining proper depth. That there are so many aids tells you how difficult it is to maintain that perfect depth with a moldboard plow. You will never be perfect in all places at all times.

 

[Chilly807]

A lot depends on your soil as well, if you go too deep you're turning up hard-pack clay that's of no benefit to your top crop. Any more than 6 inches in my part of the country is a waste of time.

Generally, the 50% depth vs width rule of thumb is ideal, the plow is designed to work best at that depth.

Sean

 

[hunterridgefarm]

It also depends on the crop being planted, soil composition (clay, sandy, etc), and soil compaction. For deep rooted crops like tomatoes and such I plow as deep as possible. If you use a hiller you may not need to plow as deep.

Cover crops and crops like cotton, soy beans, corn, rye, and wheat may require no plowing and can be planted with no-till drill or planter.

Some areas of my field are plowed deeper than others and some areas I only need to disk or use the rear tiller. IT all depends on my rotation and crop being planted. But then again I have a sandy loom soil.

 

[oosik]

Thanks for all the info - I usually go 8"-10" deep which will generally bring up the 1980 Mt St Helens volcanic ash. None of my land has ever been farmed which means, in most areas, the sod is around 4" or more. True blue-grey clay is at least three feet deep in those areas where the soil is that deep. Approximately 30% of my acreage has less than a foot of soil and is only good for open range land. What I end up with is small areas where the soil is adequate to raise a crop be it grains, grasses or veggies.
I'm located in what is known as the channeled scablands - the result of multiple outpouring from ancient Lake Missoula. This is also the very northern portion of an area called the Palouse - known for its fantastic wheat farming. I got more of the scouring effects than the soil deposition results.