Prevention of nutrient imbalances in calcareous soils

摘要

Calcareous soils are packed with calcium carbonate but the availability of calcium, and other nutrients is often severely limited. Calcium dificiency symptoms, in particular blossom end rot, are not uncommon on these soils but an appropriate fertigation program can help alleviate the problem. Blossom-end rot (BER) in crops such as pepper, chili and tomato is caused by calcium deficiency. It is one of the most common nutrient disorders and. depending on severity, it may result in a large reduction of crop yield quality or just a slight decrease on the marketable yield. Calcium-deficiency-related disorders are a common phenomenon in fast-growing and low-transpiring organs particularly of modern hybrid varieties. Moreover risks of Ca-deficiency in such organs apparently depend on their shape: Oval to elongated fruits are more prone to Ca-deficiency than round-shaped ones, which seems to be due to increased restrictions of Ca-mobility in such fruits. Symptoms of Ca-deficiency often appear on maturingfruits: Water-soaked spots at or near the end of the blossom arc typical. When fruits ripen, these spots enlarge and become dry, sunken and often flattened, brown to black in color. Secondary infections often aggravate the situation.