|
Aberdeen MS | One of the things to remember ron, in a conventional system, we have been broadcasting across the entire profile.
Speaking in somewhat general terms, when doing that, in many cases the nutrients are either subject to ion/cation "tie up" and/or leaching. One example, N moves with the "water table", dry years the "available" N within the root zone goes down in depth. A portion P and K will attach to the soil particles and be "released" at a later time. In the case of the form of the majority of the fertilzers used today, the amount that is applied this year, is not 100% available to the crop this year. Only a fraction is.
In the situation you stated 1 unit nutrient/1 unit grain yield (just to keep it simple as you stated), depending on which nutrient one looks at, the crop will only recieve from .2 units to .8 units from this years applied fertility program. The rest is obtained from the "stores" of the soil.
Now it can be, and has been, argued that the soil will be depleted of nutrients if 100% is not replaced from what has been taken off. In one sense of the word, that is true. But, the soil has the ability to "regenerate" itself to some degree. In my neck of the woods, it's been proven, that we can grow somewhere around 50 - 70 bu corn without any type of nutrient replacement year after year in normal climate conditions. Non, zip, nadda fertilizer. How many nutrients are needed for 80-100 bu corn???? Not a whole lot. What level is your "soil bank" at today??? It's been estimated by many different university studies, that it would take upwards of 15 - 20 years to deplete a very very high K testing soil in some/many soil situations down to medium/low levels. But yet, we put down commercial fertilizer for 150 bu of corn taken off the field. Are we building levels already???? Or are the soil tests and recommendations taking into consideration the soils natural ability to "rebuild"??? Who do we beieve, the universities or the dealer?? I don't have an answer for that, you have to decide that for yourself.
By banding, we are reducing the need of the plant to rely on "stored" nutrients because of the concentration of commercial nutrients within the "root BALL" zone. The plant will still stretch it's roots out searching for water, but we don't have to worry about nutrient "tie up" limiting what the plant needs and gets. IMO, we are putting our $$$ to better use on a year by year basis by banding vs broadcast fertilizing. One can fine tune their fertility program and get a better ROI from year to year.
By moving your strips year to year, over time, the entire soil structure IS covered, doing basically the same thing as we are doing now.
I'll try to draw it out, not sure if it will come across as I want it to.
| 15" | 15" | Plant and band into one 15" zone for 2 years, then move over and repeat in the next 15" zone for 2 years. In the course of 4 years, we have put down nutrients across the 30" band, the roots don't go more than 7.5" to get to placed nutrients and tap into the "stored "nutrients". We already do that side dressing N or putting on NH3. That's banding already and most agree it's the most economical way to do it. Only thing is, N is NOT one of the nutrients to cut 50% (just repeating what Dr Rheems suggests in some instances). But P and K are totally acceptable to do so, it just takes a higer level of management of your fertility levels (maybe sample yearly???).
We are all "stuck" in the knowledge we achieved from our father's and grandfather's farming experiences of years ago. Only thing was "then", commercial fertilizer was cheap and profits were more easily attainable than today. If a little was good, more was better. It was the way it was done for years and years and it was very successful. But we can be just as successful with less today. We just have to watch things a little closer, that's all.
A poor comparison, but one none the same. Go the bar, drink say 6 beers, that would be about 60 - 72 oz of fluid give or take. Then drink 6 shots of 80 proof "whatever". The exact same amount of alcohol, but the shots give you more "bang for your buck". The stomach just has that much less fluid to "process" with the shots vs the beer.
Pick and choose your form of nutrient... some give more "available now" than others do. Just do a little research and find out is it a "shot", "mixed drink", or a "beer".
Not picking on any one program or another, endorcing one over another. Just trying to explain and provide some information for you think a bit and hopefully understand a little more. Nothing more, nothing less.
HTH
Bruce | |
|
Lamberton Strip Tillage Days
