|
| Over the years, on this forum, those in the north (Minnesota, mostly) believe there is a yield benefit to in furrow or popup fertilizer because it gets the crop off to a fast start that it definitely needs in a normally short growing season. Nearly everybody else see's a nicer looking crop when its small because its flooded with nutrients, but many don't see a yield benefit at harvest, most years. One western Illinois former participant on this forum was very vocal about the lack of yield response. In his reported experience, decades of split applications had convinced him that the in furrow applications gave no yield response, but cost money and so were not a good idea. Some have reported a bit earlier maturity with in furrow applications, which in our rain shortened cool summers of late, would be a definite benefit.
I think its safe to say that crop response to in furrow fertilizer will depend a great deal on soil moisture and so root growth. With a very wet spring like this one in the corn belt, corn roots are going to be short, so may not reach nutrients at mid row. Corn keeps wet roots short to keep from drowning, then when the summer turns dry those short roots starve the corn for nutrients and moisture. In a dry spring the roots with range further and find more nutrients while going out for moisture. And there is a possibility of root pruning or damage from too much reactive fertilizer close to the furrow that can limit moisture uptake and so yield.
The only way experiment like you want can tell which fertilizer application is getting into the plant is by some very modified fertilizers with some tracer, like different isotopes of N detected by extremely fancy chemical analysis that is not practical on the farm. Otherwise your experiments will be confused by the propensity or lack of root growth and soil moisture effects on root growth which will vary according to the ancestry of the plants and you don't know that the seed sack wasn't a blend of varieties (on purpose or accidental) to add different responses plant to plant. Ideally you need to take plant samples from the same location in the same plant to reduce these variable, but that tends to be impractical. How much dos that sampling affect THAT plant's take up of nutrient?
This year, my tenant worked most of the fertilizer into the 8 or 10 wide strips made by the Soil Warrior. Unless he burns roots (32% this year, urea last year) the crop should do OK on less N than if worked in all over the field. We'll see. I did better per acre in 2007 with 32% 2" offset and then side dressed, 173.2 bu on 111 units of N (after poor beans) than he did in 2009 with the Soil Warrior after better beans (146 bu). Wet spots hurt the average yield a lot in 2009 as they did in 2008.
Gerald J. | |
|
Nutrient levels in a tissue test? Levels due to in furrow treatments or soil levels.
