SHORT-TERM EVOLUTION OF THE CHEMICAL PROPERTIES OF TWO SOILS FROM SOUTH-CENTRAL CHILE FERTILIZED WITH DIFFERENT CALCIUM SOURCES

Abstract

The use of fertilizers based on calcium (Ca) generates changes in the soil chemical properties, affecting acidity, sum of bases (BS), and Ca and magnesium (Mg) concentrations in the medium to long term. However, there is no information available about short-term changes. A study was conducted to determinate the most readily available Ca source and the best impact on the chemical properties of two different types of soils from south-central Chile, texture class loamy (Haplaquept) and clay (Duraqualf), respectively. The study was conducted under controlled conditions, using different Ca sources (Ibisoil, Nitrate, Clorhide, Sulphate, and Carbonate of Ca). The soils were fertilized with 100 mg kg-1 of Ca and incubated for 16 days at 25°C and 80% of available water. Results indicate differences in some chemical properties that depend on the soil. The highest pH value was obtained with the use of carbonate alone in the loam soil, while no differences were found in the clay soil. Similarly, no significant differences were observed in terms of Ca and K concentrations due to the fertilization treatments in any of the soils, but all of them increased Ca concentration compared with the control treatment. The highest Ca/BS ratio was obtained with Ibisoil. The lowest electric conductivity (EC) was obtained with Ibisoil and Ca Carbonate in both soils, while the highest sodium concentration and EC values were obtained with Ca Clorhide. The fertilizer with the highest increase in the Ca/BS ratio and the lowest EC was Ibisoil.