Abstract:
This study investigated and established the variation of soil nitrogen, total carbon and phosphorus
across closed forest; crop-agriculture and livestock disturbed sites. The study provides useful
information for local management strategies. It sets initial basic data on the soil status of Uzigua
Forest Reserve after 50 years of crop-agriculture and livestock grazing pressure. Forty-seven (50 m
× 50 m) quadrats were established on each land uses for soil samples collection. Total nitrogen
was analyzed by Kjeldahl acid-digestion, total carbon by the Walkley-Black procedures and
phosphorus by Bray-II method. The mean values (percentage) were nitrogen = 16.07 ± 0.34, 1.75 ±
0.25, 6.5 ± 0.20; carbon =14.48 ± 0.23, 11.81 ± 0.13, 12.24 ± 0.30; phosphorus =14.12 ± 6.57,
17.74 ± 3.96, and 13.31± 2.86 for closed forest; agriculture disturbed and grazed sites respectively.
There was a slightly lower amount of total carbon on crop agriculture disturbed sites than on thelivestock grazed land uses. Carbon-nitrogen ratio was higher in closed forests than in the disturbed
sites. The relationship between forest degradation and soil nutrient status is an indication that the
below-ground nutrient pools are mainly determined by activities, which disturb the above-ground
components mainly vegetation. To restore soil fertility status, it is important to establish the
management of the disturbed sites through restoration of vegetation and minimization of
disturbances.
