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Re: elevation maps for vra maping

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April 30, 2014 04:10PM
Apparently your issue is more of an agronomy question than mapping procedures. If I may, here are some opinions:

1. Don't try to be smarter than your data can prove you to be! Do you have yield data that confirms that elevation and yield are related?
Actually, I am not as concerned with 'elevation' as I am with slope; or at least that is my case in SE Indiana.
2. Whatever you decide to use as your decison maker logic, TEST it in plots. You can insert strip plots inside your vra maps to test your
theories. if you need help with them, i am sure Kathy can steer you thru this process, or post and i can get back to you soon.
3. Be aware that corn and soybeans tend to behave differently. This is not an exact science, but more times than not i get corn yields to corrrelate with soil types than i do with beans. Soil type is a "sorta" indicator of slopes and/or elevations if you know how to interpret your soil type codes (eg. MmB3 is a Miami (lighter soil with shallow rooting zone) and B = slope (I think it is 2-4%) and 3=erosion factor. so, basically, this is a shallow soil, sloping or hilltop, and somewhat eroded. I would back off on corn populations, and incresae soybean populations.
4. Dont underestimate the influence of weather. Corn usually like deeper, better water holding areas of the fields, especially in 2012 & 2013 when we had dry summers in SE Indiana. Beans do not tolerate "wet feet" very well, so be careful on very poorly drained soils. They tend to branch more on higher fertility and higher CEC soils, but this can be influenced by variety, too. Typically we increase population on "thinner" soils.
4. Dont try to be smarter than your data can prove you to be! (yes, i know i said that before) Try a few things, insert test plots, then evaluate your data keeping in mind the weather influences on the crop for the year.

Contrary to popular belief, There Aint No Easy Button for determining vra populations in corn and soybeans in SE Indiana, but i am still looking for one and encourage all growers to do the same! Seedsmen possibly have a bit more insight into their varietal responses than most of us, so they may be a little more prepared to make valid rough estimates of preferrred seeding rates.

ps. this is my story and i am sticking to it!

Roger DuMond
NextGPS Services
1330 N. Anderson ST.
Greensburg, IN 47240

(812) 663-5081
SubjectAuthorPosted

elevation maps for vra maping

jzillmer34April 30, 2014 12:01AM

Re: elevation maps for vra maping

KathyClineApril 30, 2014 07:56AM

Re: elevation maps for vra maping

jzillmer34April 30, 2014 10:27AM

Re: elevation maps for vra maping

KathyClineApril 30, 2014 03:01PM

Re: elevation maps for vra maping

Roger DuMondApril 30, 2014 04:10PM



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