Nutrient Deficiency

.Calcium is a vital nutrient, performing a large number of vital roles in plant biology. It’s a crucial component in plant cell walls and helps transport other minerals from one side of cell membranes to the other. It’s also involved in some enzyme functions. It’s what’s known as an immobile nutrient – once the plant has put it to use in one part of its structure, it can’t be relocated. That’s why we see deficiency in young leaves first – even if old leaves have more than enough, the calcium is fixed and can’t travel to where it’s needed. Without enough calcium, those membranes become weak. The cell walls can’t control their permeability, resulting in the leeching of vital nutrients and an eventual waterlogging of affected cells. Mostly we see it as yellowing leaves, especially in newer growth, and fruit that becomes soggy and sodden from too much moisture. Magnesium Magnesium is just as important. It’s a key component in the construction of chlorophyll, arguably the most important of all chemicals inside a plant. Chlorophyll is the powerhouse of the plant. It’s responsible for turning oxygen and water into sugar, fueling all the plant's growth. Without it, there’s no chance of vigorous growth at all Unlike calcium, magnesium is mobile and can be redeployed, so to speak, if the plant becomes deficient. As a result, magnesium deficiencies show in older leaves first, as the plant shifts its dwindling supplies to new growth. Chlorosis is the defining trait of magnesium deficiencies. Leaves turn yellow, from the oldest to the youngest. It makes sense – after all, no magnesium, no chlorophyll. Many Calmag solutions include iron, usually as a chelate. This is because many of the conditions that lead to soils poor in calcium and magnesium can also lead to low levels of iron, so it pays to cover all bases. Iron deficiencies also cause the same sort of chlorosis as magnesium deficiencies, so it sometimes pays to apply both at once. (Chelation is a type of bonding of ions and the molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands are called chelants, chelators, chelating agents, or sequestering agents. They are usually organic compounds, but this is not a necessity.) Others will include nitrogen, too, presumably because plants need a fairly consistent supply of the stuff, and a deficient plant is likely to spring to life, hungry and ready to grow, once the deficiency is corrected. This is not the case for all brands, so it pays to check – there are plenty of cases where a low or nitrogen fertilizer is preferred. Calcium and magnesium work in concert within the plant, and so for many years it was assumed you had to ensure a good ratio of calcium to magnesium in order to get good growth from your plants. We now know that it’s both simpler and more complicated than that. The ratio of calcium to magnesium in the soil isn’t important, provided there’s enough of both for whatever is growing. However too much calcium can cause a drop in available magnesium. The two get along and readily bind to each other. You may well wind up with a magnesium deficiency if you go too hard with a purely calcium-based amendment. It’s why Cal-mag fertilizers are so useful – they prevent magnesium depletion while addressing both deficiencies at once. Cal-mag is best used regularly. As calcium is non-mobile, it needs to be present in the soil for use all through the growing season. As flowers and fruit develop it’s especially crucial to keep everything well-fed and clicking along. This is especially true if the weather has been erratic – plants draw calcium from the soil in water, so if the weather has alternated from very wet to very dry, it interrupts that uptake.