Calcium Magnesium (CalMag) 1kg
Calcium and magnesium are essential plant nutrients. They are called "secondary" nutrients because plants require them in smaller quantities than nitrogen, phosphorus, and potassium. On the other hand, plants require these nutrients in larger quantities than the "micronutrients" such as boron and molybdenum.
Calcium
The primary function of calcium in plant growth is to provide structural support to cell walls. Calcium also serves as a secondary messenger when plants are physically or biochemically stressed.
Calcium deficiencies do often occur in South African soils. Soils with favorable pH levels are normally not deficient in calcium. Acid soils with calcium contents of 500 pounds per acre or less are deficient for legumes, especially peanuts, alfalfa, clovers, and soybeans. At this level, limited root system crops such as tomatoes, peppers, and cucurbite would also need additional calcium. Soluble calcium is available as the Ca2+ ion and is needed for peanuts at pegging time and for peppers and tomatoes to prevent blossom end rot.
Available calcium can be lost from the soil when it is (a) dissolved and removed in drainage water, (b) removed by plants, (c) absorbed by soil organisms, (d) leached from the soil in rain water, or (e) absorbed by clay particles. Deficiency symptoms include death at the growing point, abnormally dark green foliage, weakened stems, shedding flowers, and any combination of these.
Magnesium
Magnesium is the central atom amid four nitrogen atoms in the chlorophyll molecule, so it is involved in photosynthesis. It serves as an activator for many enzymes required in plant growth processes and stabilizes the nucleic acids.
Interveinal chlorosis is a deficiency symptom in crops such as legumes, corn, sorghum, cotton, and certain leafy vegetables. (Interveinal chlorosis is a yellowing between the veins while the veins remain green.) The leaves may become pink to light red and may curl upward along the margins.
