Page 496 - FRUTAS DEL TRÓPICO

496 Frutas del trópico

Triosulfate salts
AI (SO ) + 6H O 2AI(OH) + H SO
2 4 3 2 3 2 4
aluminium sulfate + water gibbsite (solid) + sulfuric acid

Replace calcareous soil with acid soils

It is impossible to acidify soils that have high contents of calcium carbonate in South Florida.

Replacing calcareous soils with acidic soils is an alternative. Unfortunately, acidic soils may

eventually be neutralized by irrigation and ground water that is saturated with calcium car-

bonate. One of our experiments was to examine the acidity changes and buffering capacity
of three types of acidic soils (silica sand soil, red clay soil and a mixed soil) used to establish

tropical plants in a Tropical Garden, Florida. The three areas were excavated to remove native

calcareous soil and filled with acidic soils. Various tropical plants were planted. Soil samples

were collected vertically every 10 cm from soil surface to bedrock shortly after filling and one

year later. Results showed that both silica sand and mixed soils have been neutralized and the

soil pH values were over 7 in all soil depths after one year (Fig. 1). However, less than 10

cm surface and bottom soil layers of red clay sand were neutralized and the soil pH in the

middle of soil profile were unchanged due to the higher buffering capacity. Column leaching

study indicated that acidity in the red clay soil would be neutralized within four years by the
irrigation water and capillary movement from groundwater with high concentration of calcium

bicarbonate.

Soil organic amendment:
Using organic materials as soil amendments on Florida soils usually improves soil fertility, and

generally, but does not always increase crop yields. Soil organic amendments are usually in the

Universidad Autónoma de Chiapas