Relación entre el pH y la disponibilidad de nutrientes para cacao en un entisol de la Amazonia colombiana

Abstract

Liming is a common practice in acid soil management; however, the information on liming in cacao soils of the Colombian Amazon region is precarious. Incubation curves were built in a highly acid Typic Udorthents cultivated with cacao (Theobroma cacao L. - Malvaceae), for which increasing doses (0 - 1 - 3 - 5 - 7 - 9 -11 Mg/ha) of dolomite lime (CaMg(CO3)2) and calcium carbonate (CaCO3) were used, in order to establish the type and amount of liming material (ME) with better reactivity, and the one that is better favored with the acidity changes: pH, Al3+, H+, total acidity. Models to estimate the ME dose needed to manage the soil in order to obtain the desired pH (≥5.5) were generated. Subsequently, the soil was then limed under field conditions and pH, Al3+, Al in solution (Alsol), aluminum saturation (sai), cation exchange capacity (cec) and N, P, K, Ca, Mg, Zn, Cu, B, Fe and Mn availability were evaluated. The results show that the greatest reaction of liming materials in these soils occurs after 60 days; applications of 7 Mg/ha allowed to raise the pH from 5.5 to 6.0 and decreases Al and Fe levels. These changes improved the cec and nutrient availability (Ca, Mg, P, Zn) for cacao without affecting other nutrients such as N and K.