PATTERNS OF NUTRIENT AVAILABILITY AND EXCHANGEABLE ALUMINUM AFFECTED BY COMPOST AND DOLOMITE IN RED ACID SOILS IN LAMPUNG, INDONESIA

Abstract

Planting in red acid soils, widely distributed in Indonesia, is generally related to limited crop
productivity due to their initially low nutrient-supplying potential and soil erosion. Dolomite is commonly
used to raise the soil pH in acid soils in Indonesia, where it has been beneficial as a fertilizer comprising
calcium (Ca) and magnesium (Mg). Compost is also commonly used to improve the chemical and physical
properties of these soils. To prepare a piece of land to be cultivated as a pineapple plantation, dolomite and
compost are applied to improve the soil properties and to decrease the aluminum toxicity. A greenhouse-scale
experiment was conducted in this study to determine the patterns of changes in the soil nutrients due to
dolomite and compost applications during the land preparation which generally takes 12 weeks. The
experiment was done with soil incubation in a polybag, and the aim was to learn the effects of the dolomite
and compost applications on increasing the soil pH, the availability of nutrients, and the decrease in
exchangeable aluminum (Al) in the soil. The results showed that the applications of dolomite and compost
could significantly increase the soil pH. The patterns of changes in the soil nutrients, such as Ca and Mg,
showed strongly positive correlations with changes in the soil pH, but a good relationship was not seen for K
and Na. The exchangeable Al in the soil showed a good quadratic correlation with the soil pH and decreased
as the soil pH increased due to the applications of dolomite and compost.