Humphry Davy
Member
I'm setting up the excel program with steve Soloman and mike A's recomendations, looking at the two when our soil density is factored you see some major differences in K.
For steves, he recommends up to 543 lbs/acre of K when you reach 39 CEC and remain there for any TCEC higher than 39. For a soil with TCEC at 39 that equates to 1.79% K. For a TCEC soil of 100, that would equate to about 0.7% base saturation of K, but his sodium recomendation remains at 1%. I don't like the idea of Na levels being higher than K. Also if you take K away from the sites, something else has to fill those sites. If that's H+ then your soil pH will be lower. Due to his max limits on micros, the variable bases (Mn, Fe, ect) recomended saturation % would lower as soil TCEC raises. So Id assume you'd have more sites filled with H+ and therefore more Al 3+ And Fe from acidic soil conditions.
For mike's, he recomendends 2-5% K.
Another difference is Steves limits on all micros and Mike only has max limits on Cu and Zn. So when you factor in our soil densities, all the micros that were adequate in the original soil test data (with the wrong density) are now very excessive. I think what it boils down to is steves soil plan wAsnt design for a soil over 50 TCEC.
I'm thinking of shooting for 1.5-2% K. perhaps Na at 0.5-0.8%, then use a paste test to see what's in the soil solution. For micros im going to follow Mikes and again see what the paste test shows. As for the free sites from the less K%, im going to run Mg to 15%-16% and Ca at 68%.
For the program, I've put steve and mikes recomendations side by side so you can choose, and I made all the major cation saturation % variable so you can choose your own Ca, Mg, and K%s.
For steves, he recommends up to 543 lbs/acre of K when you reach 39 CEC and remain there for any TCEC higher than 39. For a soil with TCEC at 39 that equates to 1.79% K. For a TCEC soil of 100, that would equate to about 0.7% base saturation of K, but his sodium recomendation remains at 1%. I don't like the idea of Na levels being higher than K. Also if you take K away from the sites, something else has to fill those sites. If that's H+ then your soil pH will be lower. Due to his max limits on micros, the variable bases (Mn, Fe, ect) recomended saturation % would lower as soil TCEC raises. So Id assume you'd have more sites filled with H+ and therefore more Al 3+ And Fe from acidic soil conditions.
For mike's, he recomendends 2-5% K.
Another difference is Steves limits on all micros and Mike only has max limits on Cu and Zn. So when you factor in our soil densities, all the micros that were adequate in the original soil test data (with the wrong density) are now very excessive. I think what it boils down to is steves soil plan wAsnt design for a soil over 50 TCEC.
I'm thinking of shooting for 1.5-2% K. perhaps Na at 0.5-0.8%, then use a paste test to see what's in the soil solution. For micros im going to follow Mikes and again see what the paste test shows. As for the free sites from the less K%, im going to run Mg to 15%-16% and Ca at 68%.
For the program, I've put steve and mikes recomendations side by side so you can choose, and I made all the major cation saturation % variable so you can choose your own Ca, Mg, and K%s.
