Table 1: Chemical characteristics of the top (0–10 cm) soil layer under and outside the canopies of Acacia sieberiana trees in Songa pasture, southern Rwanda.

Soil propertiesMeans under tree canopy ( )Means under open area ( )

pH5.79 ± 0.135.44 ± 0.08 *
N (%)0.90 ± 0.060.63 ± 0.05 *
C (%)4.76 ± 0.313.63 ± 0.29 *
P (ppm)45.01 ± 5.7231.54 ± 4.14NS
Ca2+9.81 ± 0.554.14 ± 0.56 *
K+0.46 ± 0.030.58 ± 0.09NS
Mg2+1.91 ± 0.101.94 ± 0.21NS

and NS denote, respectively, significant and nonsignificant differences among means for soils under and away from tree crowns ( ).