Herman Warsaw did on Herman's farm. It's funny I was pondering the same thing a year ago!
Herman was quite a guy. Everyone who met him liked him and respected him. He broke the world record for corn production with 338 bushels per acre in 1975. He beat us by 100 bushels, we figured the difference was just in our soil and weather. Actually, I've since learned there is more to it than that.
I was impressed with 274 bushels per acre last year and have quoted that quite often since harvest. Herman averaged that over 15 years! Are we just getting back to where Herman was 40 years ago?
What I am impressed most with Herman's methods was his observation of plants and soil and attention to detail. I've gotten a lot better over my life but I will probably never be a Herman Warsaw.
Note his soil tests in ipni link. Soil tests were acetate extraction then like we use at Midwest and A&L. I wish we could see the saturation results from those tests but his numbers are so much bigger than mine. I am probably 100 bushels behind right there if the right conditions do occur like they did here last year.
Here is a good review of the ammonium acetate soil test extraction. There is a lot of good reading there that shows why many still rely on this method of chemical soil extraction for crop production. I like the quote from Hill Laboratories in New Zealand, "Mehlich III enhances the soil test data! Yes, I can't follow the "fudge" factor!
"The ability to estimate the fertility of soil and improve soil productivity and crop yields has intrigued mankind for centuries. Soils are dynamic in nature and their fertility status is known to change across time as nutrients are removed by the harvest of crops for food, fiber, and energy production, lost by leaching or runoff, or change in solubility/availability with time. Thus, accurate and timely assessments of a soils ability to supply nutrients to plants is needed to facilitate profitable crop production, prevent the accumulation or depletion of nutrients in soil, preserve environmental quality, conserve natural resources, and, ultimately, to insure that modern agricultural practices are sustainable.
Many scientist and observant stewards of the land have made significant contributions to our understanding of plant nutrition and soil fertility across time. However, to date, the most significant advances in modern soil testing technology have been realized in the 1900's by scientists who pioneered the early methods of rapid soil testing procedures and performed field research to observe and quantify the effects of fertilization rate on plant performance. In the early 1900's many Land Grant Institutions developed programs investigating the utility of soil testing. By the 1930's and 1940's, soil-test laboratories were being developed throughout the USA and services were being used by local clientele. Crop yields and agricultural productivity have steadily increased for the past 100 years making fertilization necessary to optimize crop production."
Herman may have not been a trained crop scientist but I think he forgot more than some of us understand!