Percent Base Saturation for Lawns

Percent Base Saturation for Lawns is Important.

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Percent Base Saturation for lawns is one of the more important results you’ll want to pay attention to with regards to your soil test.  Getting your optimum percentages that you soil analysis requires is important.

Maintaining a Calcium / Magnesium soil ratio of
7 – 1 or 8 – 1 is important for a successful lawn

Percent Base Saturation rate is something that needs to be dealt with for successful organic lawn care. It also dictates how we deal with the lawn pH of the soil.

percent base saturationThe two most common additives to raise pH are calcite lime (white powder) and dolomite lime (brown granule). Both work slowly but are effective, dolomite contains 28% magnesium.

Calcium (Ca), Magnesium (Mg) and Potassium (K) which are cations need to be at a certain percentage in order to be fully effective as they’re being exchanged in the soil. An important aspect regarding our CEC on your soil test.



Correct Percent Base Saturation for lawns :

  • Calcium (Ca) at 65 to 85 %
  • Magnesium (Mg) at 10-15%
  • Potassium (K) at 2-5%


In our example soil test results the percentages are obviously very low:

  • Calcium (Ca)= 11.7
  • Magnesium (Mg)= 1.1
  • Potassium (K) = 0.8

Just as important, if not more, is the ratio Calcium to Magnesium isn’t even close to what we need it to be.

Where we need to raise our pH which is 5.5, we’ll need to use dolomite lime instead of calcitic lime. Something very important when you go to the home improvement store to purchase lime. Don’t settle for what they have in stock. Educate the sales personal if you have to.

Had our percent base saturation been different say with the Magnesium high then Calcite lime would be used.

If the pH is low but the ratio of Calcium to Magnesium is correct at 7-1 then you would switch back and forth each year using Calcitic Lime and then Dolomite. Or better yet, as our pH score is pretty low, one application of each product applied in the spring and then the other during autumn.

cecSoil test results will have a nutrient scale of low to very high for Phosphorus, Potassium, Calcium and Magnesium.
Once again, we bring calcium and magnesium into play here. An optimum ratio for calcium to magnesium is 7-1 or 8-1.
As it should be in the Base Saturation.

Just divide the percentage of magnesium into the percentage of calcium and you’ll have your ratio.

As with changing your pH score, changing your percent base saturation for lawns will take time but now you know how to start by purchasing the correct product.

Percent Base Saturation is Crucial To Organic Lawn Care

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