Jack, I've considered your thoughts myself and have argued with my multiple personalities the plus and minuses of each side of the debate. I've decided for myself soil fertility is vitally important - even in food plotting. And, maybe, even in general habitat improvement where, judiciously applied, amending fertility can much improve plant vigor in the face of considerable challenges.
I know you are not a strong proponent of 'weed' control and I can let it go to a degree, but where perennial stands are involved I think it important to leverage the investment of time and money into establishment of such stands by doing what I can to improve the ability of the stand to survive and even flourish year after year.
A strong stand of vigorous perennials is an effective control of weeds. Get the pH right and it's the wrong pH for lots of weed species. Get the pH right and low levels of P and K are released for plant nutrition. In the worst climatic conditions, especially in the cold, wet period, ample supplies of P and K are necessary to put the perennial food plot plant in a position to explode when growing conditions become ideal. It does improve yield, but yield is a side-effect of a healthy plant.
Maybe less so, this applies to annual crops, acknowledging most are planted when growing conditions are more ideal.
So, I say, if your soil tests - a properly collected soil sample assumed - are in the high to very high range (consider understanding parts-per-million ppm), then - if your pH is ok - skip the fertilizer. An application provides little immediate benefit. At those levels it acts more like insurance. At the opposite end, very low and low levels of P & K need to be corrected to keep the return on you efforts where they will bring you joy!
And what can be said about pH that's not already been said. It doesn't have to be perfect, but keeping it in the low 6s is essential.
Food for thought....
I'm completely on board with pH. In my personal experience, I get a measurable response from both plants and deer with pH. Perhaps this is because my native pH is so low. Fortunately, one of the upsides of my clay is that lime moves slowly thorough my soils. It takes 3 to 4 tons/ac to get the pH of new ground right. It takes a number of years before my pH drops enough to require 1 ton/ac of maintenance lime.
I also completely agree that soil fertility is important, but what level of fertility and how it is achieved is were I see a deviation between farming and deer management. Because only a fraction of a deer's diet comes from food plots, there are limits to the impact we can have with them. I find bigger impacts on my herd from large scale activities that improve native foods like timber management and controlled burns. From a QDM perspective, my food plots are targeted at specific stress periods. From a hunting perspective, some of my plots are focused at attraction for kill plots.
A farmer planting a monoculture had a high plant density all of which need the same nutrients. Deer managers generally can plant mixes of crops at a much lower density and the nutrients each crop needs is different. So, with lower over all soil fertility, on a per acre basis, each plant may still get sufficient nutrition for good growth. Just like humans taking vitamins, anything that is excess of what your body needs, is pissed away. Similarly, as long as a plant has the nutrition it needs, it will grow well, and excess nutrients don't help it.
Soil tests were developed for farmers. Once I took my soil test results, without the labs recommendations, and gave them to the coop manager, and a couple friends who are soil scientists and told them what I planted and asked for fertilizer recommendations. There was a lot of variation between each of the recommendations and between those and the lab's (VT) recommendation. There is hard science to measuring soil nutrients, but it seems there is both art and science, and a lot of experience, in soil recommendations.
There are lots of factors involved, and I certainly don't criticize folks that use commercial fertilizers. I did it for many years, and will be quick to do it again, if my plots no longer meet their objectives. Most of us have a limited budget and what we don't use in one area becomes available for another. For me, money saved on commercial fertilizer can better be applied to meet my deer management objectives in other areas. That may not be true for everyone.
We are in complete agreement in the importance of soil fertility, but for me, that does not mean applying commercial fertilizer according to a soil test recommendation. It means, getting pH right, watching my plants and deer and seeing if my plot objectives are being met. If they are, I'll spend those funds on other projects. If not, I'll be first in line for the fertilizer buggy.
Thanks,
Jack