Direct and residual effects of lime on peanut performance on an acid soil of West Sumatra

Abstract

Acid soils are the largest available lands for peanut cultivation expansion in Indonesia. This study was undertaken to determine the effects of lime on peanut growth on an acid soil of West Sumatra. In the first experiment eight peanut cultivars were grown in plots with 0, 500 and 2000 kg lime/ha. Lime reduced soil Al saturation and increased peanut yields. Pelanduk and Rusa cultivars were the least sensitive to Al saturation and Banteng was the most. In the another experiment Tapir, Tupai, Florunner and Kelinci cultivars were grown under six combinations of lime rate (0, 375 and 1000 kg/ha) and methods of application (surface broadcast, shallow and deeply incorporated). The plots received 375, 2250 and 6500 kg lime/ha 29 months earlier. The plots then were planted with Srondol and Danau Dibawah rice followed by Kelinci and Tapir peanuts. Lime increased soil pH, exchangeable Ca, Mg and K but reduced extractable Al, P and SO42-. In about a year, the effects of lime extended to deeper soil layers. Roots that ceased to grow when near harvest contributed about 0.5 ton organic matter/ha. Peanut yields increased with lime and with higher rainfall. In the drier season peanut pod yields ranged from 240 kg/ha for Florunner at low lime to 1660 kg/ha for Kelinci with the high lime treatment. In the higher rainfall the yields ranged from 800 kg/ha for Tapir to 1960 kg/ha for Kelinci. In a dry period shallow incorporation of lime increased the yields over broadcast. Critical Al saturation was approximately 22 % for Florunner and Tapir cultivars, 35 % for Kelinci and 46 % for Tupai. The critical values increased to about 56 % for Kelinci and Tapir in the higher rainfall season. Florunner and Tapir yield responded almost linearly to Ca saturation. Kelinci and Tupai maximum yields were obtained at Ca saturation of 74 % and 65 %, and 50 % for both cultivars in the second crop. Peanut seedlings were grown in solution with low Ca and high Al at initial pHs 4 and 5. Root growth was enhanced by low-level Al, but reduced by initial concentration of 15 lM Al at initial pH 4 and by 50 lM Al at initial pH 5. Ca was essential for root growth but the requirement seemed low. Concentration of 150 lM reduced the toxic effect of Al.