EC Nebraska | 17821x - 4/3/2014 05:04
Every year I struggle with whether to start applying gypsum or not. No powerplants close by use it and the gypsum mines are over 200 miles away. The cheapest I have ever found any was $70 per ton delivered. I think it would take $300 / acre worth of gypsum (not all in one year) to make any headway in lowering my 35% base saturation of Mg. The other thing that is holding me back is that over 2/3's of the ground is split down the middle by a gravel road. The pH on this farm stays in the 7.0-7.4 range because it gets so much gravel dust blown onto throughout the year. The gravel / lime in this area is all very dolomitic and loaded with Mg. So not sure I'll be able to keep my Mg down even with gypsum.
Yikes!! That is bad.
What are your Ca %'s like? Can you get AMS for a decent price? If your Ca levels are at least 60% and AMS isn't too unreasonable, you could run 400-500 lbs/acre AMS on the corn. That gives you 80-100 lbs of N and enough sulfur to partially mitigate the high Mg. I would expect that to boost your yields enough to easily pay for the extra cost as well as reducing your total N needs.
It would be interesting to see how that worked on your high Mg ground. Want to run some test strips? :) Run strips of different N rates on one field and spread that field with 500 lbs AMS. (spring AMS) Set the strips so one strip ends up at your normal total N rate, one strip at 80% of normal N, and the third strip at 60% of normal N. Then this fall take stalk nitrate tests from each strip.
It's a lot of work, but then you could post the results here on AgTalk and we could all learn :) :) :)
Edited by NE Ridger 4/3/2014 07:33
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Nitrogen corn on corn
