Influence of seasonal variation and land management systems on soils and Colophospermum mopane forage mineral status in the central northern Namibia

Abstract

The study investigated the macro and micro-elements status of the soil and browse plants (Colophospermum mopane) between three land management systems over two seasons. Browse plant samples were randomlyharvested from five individual browse plants in each of the three nested 250 m2belt transects in each of the threecamps per land management system. Three soil samples per 250 m2belt transect were collected during browse sampling at a depth of 20 cm using a soil auger. A General Linear Model (GLM) procedure of SAS (2007) was used for data analyses. The browse N levelwas greater (P < 0.001) in the ranch than the game reserve and communal in both seasons. The browse Ca level was higher (P < 0.001) in the game reserve than the other land management systems in winter season only. The browse Fe, Mn, Zn and Cu levels were greater (P < 0.001) in the ranch in winter than in summer. Soil Ca level was greater (P < 0.001) in winter only in the game reserve than the ranch and the communal lands. Seasonal variations in soil P was greater (P < 0.001) in soils collected from the ranch in winter than summer. Soil micro elements, Fe levels were greater (P < 0.001) in winter in the ranch, followed by the game reserve and lowest in the communal lands. Soil Zn level was higher (P < 0.001) in summer in the game reserve than the other land management systems. The study found that variations between land management systems and seasons greatly affected soil and browse plant minerals.