Abstract:
Pyrite layer in tidal land is one of factors that causing low productivity of soil. When pyrite was oxidized on an aerobic environment that will dissolve Fe and sulphate ions, and will establish to acid sulphate soils. This layer where can exposed on the soil surface is depends on the depth itself and soil acidity produced. Pyrite depth which causing a decrease soil acidity and fertility in acid sulphate soil has not been widely know. Pyrite depth which causing a decrease soil acidity and fertility in acid sulphate soil has not been widely known. The aim of this research was to learn pyrite layer depth, changes in soil pH and the potential for rice yield, and to determine relationship between rice yields, pyrite
layer depth and soil pH changes on acid sulphate soil in Barito Kuala Regency. This research was conducted on the location of research previous where is comparing two rice cultivation methods were applied namely SRI and conventional of rice cultivation on tidal lands (rice fields) of Barito Kuala Regency. Results indicated that there are 25 rice conventional plots which had a pyrite depth of less than 50 cm (± 39%) of the research land is ptential sulfuric acid. furthermore, there are 19 SRI rice cultivation plots that have a pyrite depth of less than 50 cm (± 59%) is actual sulfuric acid soil. Base on criteria of soil acidity, namely very acidic (pH <4.5), there are 17 plots (± 27%), acids (pH 4.5-5.5),
there are 41 plots (64%) and slightly acidic there are six plots (± 9%). SRI cultivation rice yield with pyrite depth of les s than 50 cm is lower compared to a depth of more than 50 cm. finally. In conventional rice planting there is showed that an increase Ciherang rice yield is following in increasing soil pH. In SRI cultivation, Ciherang rice yield at very acidic soil pH is higher than acid soil pH and not different from slightly acidic soil pH.
