Pedogenic processes of carbonate rocks in the tropical region as a key for sustainable soil management

Abstract

Efforts to maintain the available nutrients on the soil are very important in management. This research aims to study the pedogenic processes of carbonate rocks in the tropics as a key for sustainable soil management. Five carbonate rock samples and 23 soil samples from 8 soil profiles in areas cultivated as paddy fields were analyzed. Increasing soil depth means decreasing soil organic matter content from 5% to 2%, soil pH ranges from 5.72 to 6.81, but calcium content is only in the low to moderate range (3-8%). The pedogenic process of carbonate rock shows an increase in oxide minerals and nodules both on the part of the soil used in tillage and no-tillage. Most of the calcite minerals that exist in the soil have turned into micrite (small size of calcite minerals), oxide and clay mineral which shows the weathering of calcite minerals which resulting in the release of CO2 because it is not bound in the clay mineral composition and oxide minerals. The release of CO2 gas into the air must be inhibited by the addition of organic matter through the incorporation of crop residues to the soil, so that sustainable land use can be maintained and the greenhouse gas effect can be inhibited.