Evaluation of methods for soil liming requirement to sugar cane region of paraiba state

Considering soil acidity importance under Paraiba State conditions and the existence of several liming requirement evaluation methods, this laboratory experiment was carried out to compare different liming methods for the sugar cane region soils of Paraiba State. Thus, one experiment involving Ultisol and Entisol soils incubation was conducted in laboratory, during 42 days. The treatments consisted of five increasing doses of calcium carbonate corresponding to the quantities necessary to increase the saturation of soil. The amount of calcium carbonate to achieve the treatments was calculated based on 100% of relative power of total neutralization (RPTN). After stabilizing the pH samples were collected and subsequently analyzed pH, calcium (Ca), hydrogen (H) and aluminum (Al). It was determined the liming requirement by the method of aluminum, by method using calcium and magnesium, by the base saturation method to increase saturation of 60% according to sugar cane culture and by method related to amount of limestone to reach pH 6.0 and pH 6.5. For ease of liming recommendation, methods of base saturation and neutralization of aluminum levels were the most suitable for the soils of sugar cane region of Paraiba State.