Division of Ecology and Natural Resources, Center for Development Research (ZEF), University of Bonn, Walter Flex Str. 3, Bonn, Germany; Department of Agronomy, University for Development Studies, Nyamkpala, Ghana; Savanna Agricultural Research Institute, Nyankpala, P. O. Box 52, Tamale, Ghana; West African Science Service Center on Climate Change and Adapted Land Use (WASCAL), Airport-Accra, Ghana
Kugbe, J., Division of Ecology and Natural Resources, Center for Development Research (ZEF), University of Bonn, Walter Flex Str. 3, Bonn, Germany, Department of Agronomy, University for Development Studies, Nyamkpala, Ghana; Fosu, M., Division of Ecology and Natural Resources, Center for Development Research (ZEF), University of Bonn, Walter Flex Str. 3, Bonn, Germany, Savanna Agricultural Research Institute, Nyankpala, P. O. Box 52, Tamale, Ghana; Vlek, P.L.G., Division of Ecology and Natural Resources, Center for Development Research (ZEF), University of Bonn, Walter Flex Str. 3, Bonn, Germany, West African Science Service Center on Climate Change and Adapted Land Use (WASCAL), Airport-Accra, Ghana
In the subsistence-based, nutrient-poor soils, and fertilizer-limited agriculture of northern Ghana, 45–65 % of land cover is annually burned for purposes of hunting and agricultural land preparation. The effects of burn-season, fractional nutrient losses, combusted plant parts and vegetation type on the fire-mediated nutrient cycling are unclear. We estimate and compare the plant nutrient losses associated with different savanna covers in the early and late burn-seasons and fractionate the losses into actual losses, which should be the cause for concern and the losses due to particulate redistribution. The tissue-moisture and fuel-load elemental concentrations are predominant factors that determine the quantity of fire-induced nutrient losses. About 50 % of total combusted phosphorus, potassium, calcium and magnesium load; and ~99 % of the carbon and nitrogen loads are directly lost from burned sites during burns. Generally, calcium and magnesium are redistributed in particulate forms (~100 and ~90 % respectively) and not lost from the region, phosphorus and potassium are lost in both particulate (~50 and ~75 % respectfully) and non-particulate forms (~50 and ~25 % respectively), whereas the carbon and nitrogen are mostly lost in gaseous forms (~95 %). In the early-burn season high tissue-nitrogen concentration and low phosphorus-concentration renders burn vulnerable to high nitrogen-losses/emissions and low phosphorus-losses per unit burnt biomass. A comparatively high tissue moisture, however, impedes the early burns, resulting in patches of burned and unburned vegetation that reduce the occurrence of late burns and the total losses of plant-nutrients. Early burns reduce the quantity of nutrient losses towards a more secured food production. © 2014, Springer Science+Business Media Dordrecht.