The Iowa Soybean association in its weekly On-Farm Advance newsletter
discussed limestone last week. Overall we thought the article was good, the more information the better. Also Dr. Blackmer did an excellent job in his presentation at the annual conference
, which we encourage you to look at. There were a couple of items in the newsletter we wanted to address. See our comments below italicized.
Lime is an added cost that farmers incur on a routine schedule. If you are using N, then you should be applying the equivalent offsetting amount of lime each year to maintain proper balance. Saying lime is an added cost is like saying N or seed is an added costs. It should be a necessary and important first step in any fertility plan. Why put on more P on a 5.0 pH soil? 50% of all soil P is unavailable at that pH.
Different liming products affect soil pH differently. Because they go into solution at different rates.
When buying liming products, be sure you know the composition relative to calcium carbonate (the Calcium Carbonate Equivalent). CCE is based on a laboratory standard (AOAC 955.01) this test has no relation to how a lime material will react in the soil. This is calculated by the fineness of the material as well as its chemical makeup. ECCE is the test which is calculated using a fineness factor and the CCE which is the chemical makeup. However it does not give adequate credit for a finely ground lime material. In Iowa the test stops at 60 mesh, though testing shows solubility of a 60 mesh is very low versus 100 mesh lime and thus the 100 mesh is much more effective at changing pH.
Also remember that surface applied lime will work more slowly to neutralize H ions in the soil than lime that is mixed into the soil profile by tillage. While you do get some soil to lime particle contact and could increase the speed a lime will react, the main component of how fast a lime will go to work is rate of dissolution. This is governed by the geological structure of the lime and the particle size of the lime.
For us at Calcium Products, Inc, is very important that the correct terms are used in liming (ECC vrs ECCE, etc.). There is much confusion in the market place and I believe it is partly due to people not being specific in what they are talking about and partly because lime as always been an after-thought. Our aim is to correct this, lime should be a foundation crop nutrition product and since we think about lime at least 50% of the time (gypsum the other 50% of our time, of course!) we can focus on it and make sure it gets explained properly.
Thanks again to the ISA’s On-Farm Network Staff for the great information and getting people to think about lime!
Yield Starts Here is a blog for farmers, focusing on increasing yield and profitability by focusing on the soil. It is managed by Craig Dick, a blogronomist and sales and marketing manager at Calcium Products. Find other articles by Craig and guest writers at http://blog.calciumproducts.com.