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Massachusetts | Here is a question for growers or others who are using the base saturation method.
Here is some soil test information from one of my fields:
TEC 5.44 meq
pH 6.4
OM 1.5
Ca 61.08%
Mg 14.25%
K 8.25%
Na 2.36%
My consultant would like to see Ca=61, Mg=19, and K=7.5, so that doesn't look too bad. My question is about the K. When I look at the 'pounds per acre,' I have 350 pounds of available K per acre. The base percentage is high, but the actual pounds per acre is low, because of the small TEC.
I am growing potatoes, which are heavy users of K. Further, K is supposed to leach from lighter soils like mine. In fact, many farmers around here will apply 2-300 lbs of K annually.
Now, I suspect that the base percentage ratios are much more stable in soils with higher TECs. In lighter soils like mine, it is much more of a 'moving target.' Were I to fertilize by replacemant, I would be putting down that 2-300 lbs of K annually. If I were to fertilize by base saturation, I would apply none. My fear is that by applying none, at some point I will be going backwards on the K, that is lower than the 7.5%, due to crop removal and possible leaching if we have heavy rain.
My inclination is to apply little to no K at pre-plant. After, when I get the results from my spring soil test, I might add some K at topdress if it is shown to be needed.
Is there anyone here who has experience with light soils using base saturation that would like to comment on this?
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Base Saturation Farmers, Potassium Question
