Changes of pH, Available Phosphorus, and Trace Element after Calcium Hydroxide Liming of Acid Sulphate Soil

Abstract

Acid sulphate soil can be improved for plant growth. The objective of this research is to study the changes of pH, available phosphorus and trace elements after calcium hydroxide liming of Moo Nho [Sulfic endoaquepts, fine, mixed, acid] and Thon Sai [Sulfic (tropic) fluvaquents, fine-loam, mixed, acid] soil series samples. Five treatments and 3 replications ; Unlime, 1/4 liming of lime requirement (L.R.) for pH = 7,  1/2  liming of L.R. for pH = 7, liming of L.R. for pH = 7 and  1 1/2 liming of L.R. for pH = 7 were conducted by completely randomized design. pH, P, Fe, Mn and Cu were determined after 40, 80 and 120 days of incubation. The results showed that in Moo Nho soil series samples the increasing pH was varied to the liming quantity. However, it did not reach the expected pH value. The highest P appeared on the treatment of liming adjustment to neutral. Mn increase in the treatment of liming lower than neutral. But, its quantity was reduced in the treatment of over liming. Cu was decreased after liming. Changes of pH, P, Fe and Cu in Thon Sai soil series samples were similar were similar to Moo Nho soil series ones. However, the highest of available P occurred in the treatment of   1/2  liming for L.R. = 7. Where as, Mn was  decreased by the rate of liming. Every level of liming increased pH of Moo Nho soil series sample (p < 0.01). Mn and Cu were decreased after liming for neutral and higher (p < 0.01). For Thon Sai soil series samples, P was increasing after liming in the rate up to  1/2 liming for pH = 7. Where as, pH, Fe, Mn and Cu gave the similar results to Moo Nho soil series samples. Thus, liming is a useful mean for adjusting the soil properties suitable for propagation.