Muriate of Potash, not only a waste of money...

[Richard III]

When soil K is too high applying Na will block soil K therefore lowering % K in forage. Milk fever is a sure sign of too much K. Actually not enough Ca and Mg in the forage because of the antagonistic effects of K. I would take soil samples of all your soils before planting another crop. You can than plant grain crops on high K/low Ca fields and select those fields with lower soil K levels for your grasses and forages.
Acidosis can occur when a cow eats a lot of high energy food (grains) and little fiber (grasses). As a result, the cow is not chewing its cud and not producing saliva which helps to buffer the rumen and maintain proper pH. It is a good idea for the cow to always have access to good quality hay. The cow will eat it when it starts to heat up inside the rumen.

I have now sold my cows, so no more issues with sodium for me.

I agree with what you say about acidosis, but I tried everything you said and still had issues. When there are no obvious issues with a diet, nutritionists often remove some maize silage and add some grass silage to combat acidosis. When ever nutritionists did this to the diet I knew it would make the cows worse, but they would never listen and always assumed it was me messing something up. Eventually I found an excellent nutritionist who examined the cows and diet thoroughly, just before and four days after the change. He soon concurred that increasing the grass silage in the diet made the cows more acidotic, but was at a loss to explain it. It took us two years of head scratching to work out what was going on and why, I can only guess at the mechanisms involved. The effect of adding salt to the grassland was dramatic and clear, and observed by the nutritionist and my vet as well as my self. The nutritionist looked after 50 farms, and out of all of them only one had symptoms anything like mine, and I think salt did help there too.

 

[SilliamWhale]

I know there is some opposition to the base saturation method but using the Albrecht system with Neal Kinsey has served me well over the past 20 years in North America and Europe. That does not mean all problems are solved. Soil nutrients are not the be all and end all. I am always open to learn more about soil science and crop production.
When someone does want to follow the base saturation method use Neal Kinsey and PAL (Perry Agr. Labs). However, follow the rest of the recommendations as well. The trouble with research is that they only look at 1 or 2 nutrients at a time. It takes many nutrients to maximize yield, and addressing only 1 or 2 of them while others are deficient, will likely not maximize yield.

I don't find that to be the case. I think research tends to look at various formulations and levels of nutrients quite often.

That said my mind is not closed to all this, are there any examples of how you've maximised yield through your methods? And what in particular would the ratio theory pick up that the quantity theory missed out on?

 

[Eltjo]

I don't find that to be the case. I think research tends to look at various formulations and levels of nutrients quite often.

That said my mind is not closed to all this, are there any examples of how you've maximised yield through your methods? And what in particular would the ratio theory pick up that the quantity theory missed out on?

Using the base saturation method allows you to apply the correct amount of Ca and Mg because the CEC is used in that calculation. If we take 2 different soils sandy loam and clay soil (with the same low pH), 1 ton of limestone may be good for the sandy loam but not enough for the clay soil. You have to know the nutrient holding capacity of that soil before you can calculate how much to apply. Using the buffer pH you can also calculate how much lime should be applied but it won't tell you how much Ca and Mg is needed.

A lab which says your Ca needs to be "X" and Mg should "Y" is still working with ratios eventhough they are not saying it.

On research we can spend a lot of time talking back and forward. A field of potatoes will have a lot of variability due to seed and soil factors. Statistically the coefficient of variation could easily run 25-30% so when you try to proof that a product works or not a 5-10% yield increase is not enough to be significant. You may need to repeat it 5 years. I do always learn a lot from doing research.

 

[SilliamWhale]

Using the base saturation method allows you to apply the correct amount of Ca and Mg because the CEC is used in that calculation. If we take 2 different soils sandy loam and clay soil (with the same low pH), 1 ton of limestone may be good for the sandy loam but not enough for the clay soil. You have to know the nutrient holding capacity of that soil before you can calculate how much to apply. Using the buffer pH you can also calculate how much lime should be applied but it won't tell you how much Ca and Mg is needed.

A lab which says your Ca needs to be "X" and Mg should "Y" is still working with ratios eventhough they are not saying it.

On research we can spend a lot of time talking back and forward. A field of potatoes will have a lot of variability due to seed and soil factors. Statistically the coefficient of variation could easily run 25-30% so when you try to proof that a product works or not a 5-10% yield increase is not enough to be significant. You may need to repeat it 5 years. I do always learn a lot from doing research.

But don't you calculate the base saturation percentage figures on measuring the CEC at a ph of 7? Given that CEC changes when pH changes how do manage to extrapolate this reliably in the field on various soil types, various crop types in a variety of climatic conditions?

The other thing I'm wondering. What if your ratio of say Calcium and Potash or Magnesium and Potash is "correct" but the soil happens to be low in potash? The BCSR would indicate that no potash would be necessary even though in quantitative terms you may be short. There would be an economic gain from using mineral K (or other sources) would there not?

Re the bit in blue. I wouldn't say they are working in ratios, I agree that there is a balance to be had and too much of one nutrient can effect the availability of another but the lab would still be working on getting a minimum of all nutrient availabilty and not advising much more than the minimum needed on grounds of cost of wasted nutrition.

 

[Eltjo]

But don't you calculate the base saturation percentage figures on measuring the CEC at a ph of 7? Given that CEC changes when pH changes how do manage to extrapolate this reliably in the field on various soil types, various crop types in a variety of climatic conditions?

The other thing I'm wondering. What if your ratio of say Calcium and Potash or Magnesium and Potash is "correct" but the soil happens to be low in potash? The BCSR would indicate that no potash would be necessary even though in quantitative terms you may be short. There would be an economic gain from using mineral K (or other sources) would there not?

Re the bit in blue. I wouldn't say they are working in ratios, I agree that there is a balance to be had and too much of one nutrient can effect the availability of another but the lab would still be working on getting a minimum of all nutrient availabilty and not advising much more than the minimum needed on grounds of cost of wasted nutrition.

When the CEC increases with pH you get an increase in pH dependant charges. A good example is chalk soils where the Ca is very high. The CEC appears higher because more negative charges are exposed in the soil. To find out the true CEC the lab would run a test which takes longer to do. Most labs don't unless you ask. CEC is a calculated number based on the amount of cations (in moles) in the soil. Add these all up together and you have a CEC. On the high Ca soils, the CaCO3 in between the soil particles are also showing up in the analysis and therefore added to the CEC number. Therefore you would get an overestimated CEC number. This is the first time I hear the statement that CEC is measured at a pH of 7. The pH of different extraction solutions varies. They can be 4 but also 7 (or another pH).

The recommended range of %K is 2 - 7.5%. The ideal %K depends on the crop. For a lot of grain crops 2% is min but 4 - 5% is better. When dealing with crops like potatoes and sugarbeets, 5% is min and 7.5% is better. However, when you reach 7.5% and Ca and Mg are not at ideal you could run into trouble with quality. Potatoes with low starch and sugarbeets with lower usable sugar. The micronutrients are also more important when K is that high because of antagonisms. You would run into some of the same quality issues but yields would level out as well.

How much K to use is the question and do you apply more even when there is enough %K in the soil. This depends what your yield goal is. Personally I do recommend more K on potatoes even when there is enough in the soil. The reason is that under conventional agriculture the soil life is not ideal. There is a lot of abuse happening. So if the microbes are not helping me with the supply of nutrients I need to use extra fertilizer. Another point is soil temperature. Where I live the frost is barely out of the ground and we're planting a crop. So nutrient availability is much lower compared to warmer soils (microbes are not awake yet). The same goes for P. In terms of your yield goal I have farmers in Holland who get 70 T/ha while here in New Brunswick 40 T/ha is a good crop. So fertilizer recommendations are not the same for each farm.

Nobody wants to waste money on fertilizer and hopefully I have not done this. Money is tight no matter where you farm. I usually discuss with the farmer what his budget is and go from there. It is important that the money is not spend on micro nutrients when pH is 5.6 and he does not have enough K on his crop. There is a specific order you follow when correcting soil nutrients.