Abstract:
Ultisols is one of soil types that undergoes further weathering and displays the most active cations leaching caused by precipitation. This study aimed to observe the effect of calcite application (CaCO3) and gypsum (Ca2SO4) on valence 2 cations, such as Ca and Mg. This study was conducted in Experimental Field of Gula Putih Mataram Enterprise, Central Lampung. Split-plot design with 3 replications was used as the experimental design. The application of calcite as the main plot and the application of gypsum as the sub plot. The analysis shows that Ca analysis of leachate was relatively high than Mg if the higher rainfall happened. It could dissolve Ca from topsoil to subsoil and eventually Ca exits the soil system (solum). Meanwhile, Mg leaching by precipitation could not give clear results. It can be assumed that high rainfall would leach Ca first and then Mg, even though according to lyotropic series the bonds of Ca2+ is slightly stronger than Mg2+. It indicates that Mg solubility by precipitation indirectly caused by high Ca solubility due to the application of calcite and gypsum. The addition of lime about 1 ton ha-1, rainfall at 1264,2 mm for 166 days, caused the leaching of Ca about 596 mg and Ca uptake about 3.229 mg which is equivalent to its addition about 14.676 mg in soil. The addition of gypsum about 0,25 ton ha-1 will prompt the leaching about 538 mg and Mg uptake about 3.072 mg. Therefore, the application of calcite and gypsum in ultisols with high rainfall resulted in higher leaching of Ca compare to Mg. |
