|Fageria, N - EMBRAPA, BRAZIL|
Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 12, 2003
Publication Date: January 1, 2004
Citation: Fageria, N.K., Baligar, V.C. 2004. Properties of termite mound soils and responses of rice and bean to n, p, and k fertilization on such soil.. Communications in Soil Science and Plant Analysis. 35:15-16. Interpretive Summary: Macrofaunal activities in soil are known to affect the nutrient and organic matter dynamics and structure of the soil. Such changes in soil properties have profound influences on the productivity of the ecosystem. Termites are the dominant macrofaunal group found in the tropical soils. Termites process considerable quantities of soil materials in their mound building activities. Such activities might have potential effects on carbon sequestration, nutrient cycling, and soil texture. However, the role of termites in nutrient and organic matter dynamics, and textural changes in acid soils of Brazil are not explored very well. An experiment was undertaken to characterize soil texture and chemical properties of termite mound soils in the central Cerrado region of Brazil. A greenhouse experiment was also conducted with a representative mound soil to assess the influence of added nitrogen, phosphorous, and potassium fertilizer on growth response of upland rice and the common bean. Termite activities significantly increased the soil texture (silt), exchangeable cations, micro nutrients and organic matter content, and the pH of the mound soil. Soil acidity, in terms of the aluminum content, was decreased by termite activities. Application of nitrogen and phosphorous to soil significantly increased the grain yield of upland rice and the common bean. From the obtained results it appears that the termite activity improves the physical properties and fertility. It also reduces the acidity of the acid soils. The utilization of such soils for crop production might reduce the cost of fertilizer inputs, thereby improving the economic returns to the tropical farmers.
Technical Abstract: Termite mounds are very common in Oxisoils of the 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. Also, the study was to determine the growth response of rice and common bean to soil applied N, P, and K fertilization. Soil samples were collected from 20 termite mounds located on the experimental station farm Capivara of the National Rice and Bean Research Center, Santo Antônio de Goiás, Brazil. The average value of clay content was 354 g kg-1, silt was 217 g kg-1, and sand was 429 g kg-1. The 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. The average cation contents (mmol dm-3) for Ca, Mg, Al and Al+H were 36, 18, 1.7, and 78 respectively. The average micronutrient content (mg dm-3) for Cu, Zn, Fe, Mn were 2.8, 3.2, 135, and 78 respectively. The 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 an 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 the grain yield of the common bean, these crops did not respond to K fertilization.