Properties of Termite Mound Soils and Responses of Rice and Bean to Nitrogen, Phosphorus, and Potassium Fertilization on such Soil

Abstract

Termite mounds are very common in Oxisols of Cerrado region of Brazil where land is either under forest or long term pasture. The objective of this study was to characterize textural and chemical properties of soils derived from these termite mounds and to determine the growth response of rice and common bean to soil applied nitrogen (N), phosphorus (P), and potassium (K) fertilization. Soil samples were collected from 20 termite mounds located on the experimental station farm Capivara of National Rice and Bean Research Center, Santo Antônio de Goiás, Brazil. Average value of clay content was 354 g kg−1, silt was 217 g kg−1, and sand was 429 g kg−1. Average soil pH was 5.7, P was 3.2 mg dm−3, K was 150 mg dm−3, and organic matter content was 32 g dm−3. Average cation contents (mmol dm−3) for calcium (Ca), magnesium (Mg), aluminum (Al), and Al + H were 36, 18, 1.7, and 78, respectively. Average micronutrient contents (mg dm−3) for copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) were 2.8, 3.2, 135, and 78, respectively. Average cation saturation was 45%, Al saturation 2.8%, Ca/K ratio 10.7, Ca/Mg ratio 2.1, and Mg/K ratio 5.1. On average, soil fertility of termite mounds was higher than that of the Oxisols soils surrounding the mound. Upland rice (Oryza sativa L. cv. Maravilha) and common bean (Phaseolus vulgaris L. cv. Perola) grown on a representative termite mound soil responded significantly to applied N and P. However, with the exception of grain yield of common bean, these crops did not respond to K fertilization.