Agricultural Applications For Specialty Minerals Ground and Precipitated Calcium Carbonates
Over time the acidity of soils tends to increase. This is due to such varied sources as rainwater containing dissolved carbon dioxide, pollution and smog containing oxides of sulfur and nitrogen, using fertilizers rich in ammonia, plant roots exuding nitrogen ions, and the natural decomposition of organic matter. Substantial research has been done on the optimal pH range for various crops. Ground calcium carbonate (GCC), also called ground limestone, and ground dolomite (calcium magnesium carbonate) have long been used to lower the acidity and raise the pH of farmland, grass lawns, and golf courses. Note that the material used to “lime” soil is not actually lime—calcium oxide—but rather limestone, or calcium carbonate. Calcium oxide is too active for use in soils, and can harm crops.
GCC also has been used to reduce blossom end rot, resulting from lack of calcium, in tomatoes, peppers, eggplants and watermelons. When it is sprayed on as a water slurry, calcium carbonate acts as a sunscreen for the even ripening of tomatoes and watermelons.
Choosing a Limestone or Dolomite For Agriculture
Limestone and dolomite used for soil neutralization and pH control range in size from small sand to fine-ground minus 325 mesh. Most mechanical spreader systems are designed for particles below 35 mesh, because the larger particles react too slowly to be effective.
Nontraditional soil-neutralization techniques include the use of fine-ground 3 micron products in drip irrigation systems and precipitated calcium carbonate (PCC) in the production of mushroom spawns.
Specialty Minerals Calcium Carbonates for pH Control
Specialty Minerals Inc. (SMI) offers a number of high-calcium limestone and dolomitic limestone products for use in controlling soil chemistry. Both high-calcium limestone and dolomitic limestone are very effective in neutralizing acidic soil; the dolomitic limestone offers the added benefit of healthier plants (with the addition of magnesium). The PCCs used in special agricultural applications are usually very small in size (under 1 micron).
Consult your professional soil specialist to determine how SMI limestone can be used to yield healthier plants.
SMI ground carbonate products for agriculture are mined and manufactured in two plants in the eastern U.S and one plant in the western U.S. PCCs are manufactured in the U.S and in the U.K.
Suitable products include:
Eco-Cal® 5050 GCC – Adams, Massachusetts, high-calcium 325 mesh limestone
Marblewhite® - East GCC – Adams, Massachusetts, high-calcium 200 mesh ground limestone
AFG™ 20 GCC – Adams, Massachusetts, high-calcium 20 mesh screened limestone
Vicron® – East GCC – Adams, Massachusetts, high-calcium 3 and 5 micron fine-ground limestone
40F Dolomite– Canaan, Connecticut, 200 mesh ground dolomitic limestone
SF Dolomite – Canaan, Connecticut, 200 mesh ground dolomitic limestone
Dolocron® 45-12 dolomite – Canaan, Connecticut, 200 mesh ground dolomitic limestone
Vical® GCC – Lucerne Valley, California, high-calcium screened and ground limestone
Marblewhite® – West GCC – Lucerne Valley, California, high-calcium 200 mesh ground limestone
Vicron® - West GCC – Lucerne Valley, California, high-calcium 3 and 5 micron fine-ground limestone
Albafil® PCC – Adams, Massachusetts, 0.7 micron PCC for easy spraying and application of a thin sunscreen coating.
Albacar® 5970 PCC – 1.9 micron scalenohedral (starburst shaped), high surface area PCC, recommended for mushroom spawn production. Manufactured in Adams, Massachusetts.
Calopake® 5970 PCC – also a 1.9 micron scalenohedral PCC, manufactured in Birmingham, U.K.