Abstract
The possibility of ‘over-limping’ acid soils was investigated by thoroughly mixing pure calcite (increasing to the equivalent to 20 t ha-1 to a depth of 30 cm) with two acid soils and quartz sand in a pot experiment with wheat. All macro- and micro-nutrient elements were supplied under controlled glasshouse conditions. Dry (65ºC) yields of straw and grain were recorded and final soil pH values measured. The straw was analysed for elements for nutritional importance at the conclusion of the experiment. Even through a pH of 9.1 was reached in the sand series, no growth inhibition or disturbed nutrient uptake was found was a consequence of ‘overliming’. These results point to the possible freedom with which soils may be limed in order to maintain a sufficient reserve to counter the continuous acidification process under tropical and sub-tropical conditions.
