OrganiCalc is designed to be an aid in growing nutrient dense food, however it is not applicable for certain circumstances.

Acid soil loving crops

If you are growing blueberries, rhododendrons, potatoes or other such plants, the recommendations are good, as long as the pH is low enough. Just don’t add the lime or manganese OrganiCalc recommends. 

Pastures

These recommendations are for growing nutrient dense food, not for pasture. Aside from the expense of bringing large areas up to these levels, herbivores are very sensitive to changes in taste. Mineral application limits are much lower for pastures. Consult an analyst experienced in pasture management. Contact Erica@GrowAbundant.com, and we will share what we have learned about pasture management.

Your soil is already balanced

Usually this happens after a few years of soil mineralization. Your soil settles to a point where the plants are growing very well. You don’t want to disturb this equilibrium, or lose valuable (cation) nutrients. You want to add only enough of the sulfur anion to grow a good crop — 45 to 70 lbs/acre.

In OrganiCalc, we target an initial ratio of 68% Ca / 12% Mg for clay and 65% Ca / 15% Mg for loam or sand. We want to keep the Mg low, because it is hard to get rid of Mg once it is in. Also, we put the Ca at the high end, so it will displace excess cations. These initial targets work very well in practice.

If your ground is sandy, you will want more Mg and less Ca. If you have clay soil, you will want less Mg and more Ca. If you have achieved equilibrium and your plants are growing very well, the Ca:Mg ratio you actually have is more important than a theoretical ratio. There are actually broad ranges of balanced Ca:Mg ratios. Ca% + Mg% should equal 78% to 82%. The Ca% can be between 60 and 70%. The Mg% should be between 10% and 20%.

When your soil is mineral-balanced, it’s time to really focus on the biology.  5% organic matter is a nice number where summer is hot; 8 to 9 % is a good number where summers are coolish, such as in the Maritime northwest. Organic matter over 30% is more than enough.

Finally, if your soil is otherwise balanced and you have excess Ca, don’t try to fix it; leave it alone.