Long Term Effects of Crop Rotations with Fallow or Groundnut on Soil Fertility and Succeeding Sorghum Yields in the Guinea Savannah of West Africa

B. V. Bado et al., 'Long Term Effects of Crop Rotations with Fallow or Groundnut on Soil Fertility and Succeeding Sorghum Yields in the Guinea Savannah of West Africa', Lessons learned from Long-term Soil Fertility Management Experiments in Africa, pp.27-40, Springer Netherlands, Dordrecht, 2012

The effects of crop rotations with fallow, groundnut (Arachis hypogea) and cotton (Gossypium sp) on soil and subsequent sorghum (Sorghum bicolour) yields were studied with a 14-years (1993?2007) old experiment at Farakô-Ba (4° 20? West, 11° 6? North and 405 m altitude) in the Guinean z one of Burkina Faso. A factorial design in a split plot arrangement with four rotation and eight fertilizer treatments were used. Crop rotations with groundnut or annual fallow increased succeeding sorghum yields. Mean annual yields of succeeding sorghum increased from 547 kg ha?1 in continuous sorghum to 912 and 1,021 kg ha?1 in Fallow-Sorghum and Cotton-Groundnut-Sorghum rotations, respectively. Soils of Fallow-Sorghum and Cotton-Groundnut-Sorghum rotations released more mineral Nitrogen (N) at sowing and increased fertilizer N use efficiency from 13 to 32 units, respectively, compared to continuous sorghum. Soil organic carbon increased from 0.36% in continuous sorghum to 0.39% and 0.54% in Cotton-Groundnut-Sorghum and Fallow-Sorghum rotations respectively. Except for fallow-sorghum, all rotations decreased soil organic carbon, soil pH with an increase of Aluminium ion (Al3+) saturation. Highest quantities of extractable Phosphorus (P) were observed in mono-cropping of sorghum. Manure increased soil organic carbon (SOC), total N and available P. Manure or dolomite decreased Al3+ saturation.