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Little River, TX | I have shot my mouth off so many times concerning the nonacademic normal soils that I do not rerun the tape for one of my soliloquies.
I started out breathing in every word of academic wisdom when it came to soils. Eventually disillusionment crept in and I started to venture off the reservation.
Thanks to a Progressive Farmer article I started using plant analysis, and was lucky to draw some valid conclusions at the start. First I found my alfalfa was deficient in copper. That was fairly easy to correct. Then by pure chance I looked at Molybdenum and now it was deficient. Got that on my list of things to do and production went up, but persistence went down. With 350 ppm K it was difficult to visualize the crop was now deficient in potassium. Still I went counter to the academic wisdom and started applying 300 lbs of potassium. Then I got a 300 ppm K soil test and just over 1% K plant analysis result. Plowed out what was left of that stand and before planting the next graveled that field with Murate of potash.
Changed labs and went with a commercial lab. Found they were subject to some rather wild test results with not a mention made. some might think one out of 6 soil test being acid and the rest with an 8 pH would raise some questions. So started dividing the fields into thirds. Not for precision but looking for the wild reading. No wild reading I averaged the three and proceeded. Suffice to say I had a number of questionable results and changed to Midwest Labs in Omaha.
Mid west has some unusual results but they freely respond to my questions and provide their rational. Works for them, and I can adjust.
Pennsylvania was a big help to me. When I was just starting to question the large potash values as possibly actually being deficient, I saw a Penn State chart with a sliding scale for sufficiency using Cation Exchange Capacity as the entering argument. Worked like a champ. My only problem was and is they changed their chemistry and dropped their chart from the web site. Does not hurt my methods but I can not reference the system used.
Along the way I surmised soil test results are not a hard and fast value but are in truth a range. When using K, Mg, Ca, & Na to compute CEC and they can be off 10% to 20% and the effect of accumulating errors I was pleased to learn Midwest has a measured CEC test. For these I sampled every fall, sampled entire fields as a unit, and built a libriary of results. some fields now have 9 seperate and distinct test results and these are averaged. The measured values also show a 10% to 20% variability, which is very good actually. But averaged I feel they are close enough for my purposes.
The above is a 27 year slow learning process. Still not too bad for a State Teachers College Vo Ag degree that is more than 50 years old.
Looked at your name. Can you trace any of your ancestors to the 1680 migration to German Town, PA? My Great Grandfather went down to German Town from Bucks county for a wife. They had 12 children. The descendents have drifted off from the home place and some how my Father settled in Central Texas a lifetime ago. Please do not ask for specifics. About all I know is the family is, or was mostly Quaker. | |
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When to fertilize new alfalfa
