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Rolla, ND | Veris, EM38, Profiler.
The Veris is actually a resistivity meter, the others are electrical induction machines.
Don't really know what you are asking as far as cost and such. You mean cost to buy the machine, cost to have someone do a reading or what?
They are quite accurate but realize what you are measuring does not have only one thing.
Also don't know what you mean by available for fertility? Generally, they are used to help zone a field into production zones and do directed sampling. Basically another way of grouping similar soils. It can be used multiple ways. For instance you might want to go by your soil map but use the conductivity of the soil to more precisely delineate the soil units. After all, the guy doing the survey in most cases didn't even have a gps.
In any case, the map is most effective if not used by itself but if combined with multiple data layers. Guys want one perfect layer, but it doesn't exist.
How good a map it is depends at least in part on where you are. NDSU has been looking at this for awhile. For western ND, the conductivity was the best single type of data. For eastern ND multiple yield maps was the best. Of course the number of fields with multiple years of good yield maps is minute in my experience.
Realize too our soils are relatively quite conductive compared to much of the country.
So let's say you are in a rolling terrain, semi-arid, relatively high conductivity, young soils. Then the conductivity is a very good layer. If you have old soil, pattern tiled, low conductivity, lots and lots of changes over the years to the native fertility, well, it wouldn't be as good.
One thing the conductivity does much better than many other things is sand and salt. Shows the sand spots very well. You might say well my yield maps does that. True, but really only over multiple years. Lots of rain the sand does well, no rain it dies. Note also that it's very easy especially on one year to put the sand in with the salt and those are very different management. Conductivity really splits them well. | |
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Veris sampling
