How many years can you plant the same crop in the same spot before all
the nutrients are gone from the soil.

Danielle Davis writes

How many years can you plant the same crop in the same spot before all
the nutrients are gone from the soil.

That depends on whether you replace them or not.

There is a trial set up by rothamsted in the 19C and still running where
no fertilisers have been applied and the field is/was sown to wheat.

At least that is what is claimed. Unfortunately rothamstead do not
publicly supply this data unless you have a contract with them, and then
claim copyright anyway.

A highly deplorable situation for what claims to be a scientific
establishment, at one time government owned.

The answer, by the way, appears to depend on soiltype and the amount of
nutrients coming in via rainfall and soil breakdown.

On this farm, when we came in the 1970's, soil index levels were very
low indeed and yields by our predecessors were close to 2.5T/Ha when
adjacent farms were obtaining twice this. However our predecessors did
apply limited amounts of fertiliser.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
Note: soon (maybe already) only posts via despammed.com will be accepted.

"Oz" wrote in message
...
Danielle Davis writes

How many years can you plant the same crop in the same spot before all
the nutrients are gone from the soil.

That depends on whether you replace them or not.

There is a trial set up by rothamsted in the 19C and still running where
no fertilisers have been applied and the field is/was sown to wheat.

At least that is what is claimed. Unfortunately rothamstead do not
publicly supply this data unless you have a contract with them, and then
claim copyright anyway.

A highly deplorable situation for what claims to be a scientific
establishment, at one time government owned.

The answer, by the way, appears to depend on soiltype and the amount of
nutrients coming in via rainfall and soil breakdown.

On this farm, when we came in the 1970's, soil index levels were very
low indeed and yields by our predecessors were close to 2.5T/Ha when
adjacent farms were obtaining twice this. However our predecessors did
apply limited amounts of fertiliser.

OSU has a plot of wheat that has received manure only for about 80 years and
it averages 14 or 15 bushels an acre or 1/3 normal yields. Fifteen to twenty
bushels is about what we expect from wheat with no fertilzer on a long term
basis. There are still people doing that. They put in just enough the cows
don't starve in the winter and have a job in town that they don't do to well
at either.

I know one farm that was in cotton for 70 years and it made about 1/2
average yields not from loss fertility but form nematodes and disease. One
rotation of alfalfa put it back as a top producing farm. It was sandy farm
that was sub irrigated. That is it was only 6 to 10 feet to water and
cotton and alfalfa could tap this moisture. Not high enough to be a problem
but height enough to assure a nice crop if you could get it up.

Gordon

Danielle Davis wrote in message
om...
How many years can you plant the same crop in the same spot before all
the nutrients are gone from the soil.

depends upon the crop, as an example potatoes are very "hungry" and will
more rapidly strip the nutrients from the soil that other crops.


--
Jim Webster

"The pasture of stupidity is unwholesome to mankind"

'Abd-ar-Rahman b. Muhammad b. Khaldun al-Hadrami'

On 11/12/02 8:21 PM, in article
, "Danielle Davis"
wrote:

How many years can you plant the same crop in the same spot before all
the nutrients are gone from the soil.


You should be able to plant the same crop indefinitely as long as the
nutrients are replaced each year by fertilizer and other crop nutrients.
I've seen corn planted in the same fields for 20+ years. This is in the
central U.S.
Crop diseases and pests tend to get in those fields and cut the yields
unless the crop is sprayed. There is one corn disease that can be only
prevented by crop rotation. The name of it escapes me right now. Seed corn
companies in my area will not plant their seed corn in fields that had corn
the previous year.
There would be a dramatic yield drop for corn if it wasn't fertilized each
year with nitrogen fertilizer. The rough rule of thumb is one pound of
nitrogen for each bushel of corn.

Dean





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"Dean Hoffman" wrote in message
...
On 11/12/02 8:21 PM, in article
, "Danielle Davis"
wrote:

How many years can you plant the same crop in the same spot before all
the nutrients are gone from the soil.


You should be able to plant the same crop indefinitely as long as the
nutrients are replaced each year by fertilizer and other crop nutrients.
I've seen corn planted in the same fields for 20+ years. This is in the
central U.S.
Crop diseases and pests tend to get in those fields and cut the yields
unless the crop is sprayed. There is one corn disease that can be only
prevented by crop rotation. The name of it escapes me right now. Seed
corn
companies in my area will not plant their seed corn in fields that had
corn
the previous year.
There would be a dramatic yield drop for corn if it wasn't fertilized
each
year with nitrogen fertilizer. The rough rule of thumb is one pound of
nitrogen for each bushel of corn.

Dean

You will eventually get a disease, weed, nematode or insect problems that
cuts the yields or increases cost too much. Some crops and soils are more
unstable than others but eventually almost all crops will have some kind or
a problem if your plant the same crop year after year.

We are getting more technology that lets us do it longer but mother nature
is a hard old lady to beat. An occasional rotation will make things a lot
easier and a lot less risky that depending on just one crop. Crops and
cattle work well togeater. Spreading the risk and in my part of the world
giving you a range of options on winter and summer crops that pay well at
100 to 400 pounds of beef per acre or more if you have irrigation.
--
Gordon

Gordon Couger
Stillwater, OK
www.couger.com/gcouger