The idea of variable rate nitrogen began with the notion that we could apply nitrogen according to expected yield. Managing nitrogen by soil test and only applying what is needed is an idea that makes more sense. The shortcoming is that the window for sidedressing nitrogen is small. We have been reading for a couple of years about the chlorophyll sensors and applying nitrogen only where the plants are showing a deficit. This machine seen at this year's Farm Progress Show takes it a bit further. It comes equipped with chlorophyll sensors and it is built high enough to get through some shoulder high corn. Going through high corn gets the nitrogen to the plant just in time. This applicator is set up to apply UAN solution. It looks to have very good potential. I hope one of our local suppliers gets one so we can see the applicability. Sunday, September 11, 2011
Variable Rate Nitrogen
The idea of variable rate nitrogen began with the notion that we could apply nitrogen according to expected yield. Managing nitrogen by soil test and only applying what is needed is an idea that makes more sense. The shortcoming is that the window for sidedressing nitrogen is small. We have been reading for a couple of years about the chlorophyll sensors and applying nitrogen only where the plants are showing a deficit. This machine seen at this year's Farm Progress Show takes it a bit further. It comes equipped with chlorophyll sensors and it is built high enough to get through some shoulder high corn. Going through high corn gets the nitrogen to the plant just in time. This applicator is set up to apply UAN solution. It looks to have very good potential. I hope one of our local suppliers gets one so we can see the applicability.
having played with VR N for years, using yield maps, meters and N testing (and combos of both) of various types the reality is that a flat rate is really a variable rate.
ReplyDeleteThe growing season has more influence on the "right rate" than almost anything else at least here in S Illinois claypan soils.
High yielding areas need less N and low yielding areas need more N. Test levels could be "enough" when you took the test but if it starts raining and gets saturated your going to run out. If it quits raining then you cant put enough on. And when growing conditions are ideal, it doesnt seem to matter the rate, the corn just pours out.
Timing of application is more important in most years than amount applied.....and you had better put enough on when you do it.
That said, I am still chasing VR N rabbit......