Application of lime and compost on the newly established field with acid sulfate soil type in the Belandean experimental field, South Kalimantan for agricultural cultivation

The use of acid sulfate soils for agricultural cultivation is constrained by due to the oxidation process of pyrite (FeS), increasing the solubility of Al and Fe, which causes the pH to be more acidic. The specific strategy needed to utilize acid sulfate soil is through calcification technology combined with in situ organic materials. This study used lime at dose determined by the incubation method and organic materials from composted grey sedge plants, rice straw, and cow dung. The aim of this study was to determine the effect of organic matter on improving the chemical properties of acid sulfate soils. This research was arranged in a completely randomized design with four treatments and three replications. The treatments consisted of control (K0), lime without organic matter (K1), lime and organic matter (K2), and organic matter without lime (K3). The results showed that the application administration of organic matter combined with lime was able to increase the pH and available cations. The highest pH was 4.79 obtained after 14 days of incubation, and the lowest pH was observed in the control treatment, which was 3.47. The highest electrical conductivity (EC) value (76.50 μS) was observed in the K2 treatment, and the lowest EC value was observed in the K0 treatment (92.40 μS). The highest Eh value was found in the K0 treatment, reaching 274.5 mV, and the lowest was observed in K3 treatment, reaching 157.1 mV. There was a positive correlation between pH and EC and a negative correlation between pH and Eh with a value of r = 0.77 ∗∗ and r =-0.69 ∗, respectively