Searching for the best Methodology to Determine Lime Requirement of selected Puerto Rican Soils.

Five methods to estimate lime requirement were evaluated using four acid soils from Puerto Rico. The methods were: soil-lime incubation, Shoemaker-McLean-Pratt single buffer, Adams-Evans buffer, Sikora buffer, and an estimate based on exchangeable Al³⁺ content. Soil samples of Consumo (Typic Haplohumults), Corozal (Typic Hapludults), Alonso (Oxic Dystrudepts) and Los Guineos (Humic Hapludox) were collected at two depths (0-20 cm and 20-40 cm). Lime requirement values were estimated using a target pH of 6.5. Soil-lime incubation was the reference method. Exchangeable Al³⁺ method and the Adams-Evans buffer provided lower lime requirement values than the incubation method for all soils at both depths. The highest lime requirement values were obtained with the SMP and Sikora buffers.  Both of these methods gave similar lime requirement values. Pearson correlation coefficients indicated a good correlation  between the incubation method and the SMP (0.90) and Sikora buffer (0.90) methods. Sikora buffer method also showed a good correlation with the SMP (0.93) and the exchangeable Al³⁺ methods (0.92).