AQUACROP MODEL AS A TOOL TO DISCLOSE THE WATER PRODUCTIVITY OF BAMBARA GROUNDNUT LANDRACES FOR RAINFED FARMING IN BOTSWANA

A.S. Karunaratne, S. Azam-Ali
AquaCrop, a new decision support tool is useful in modeling and devising strategies in the choice of viable field management practices for researchers and the smallholder since it keeps a good balance between accuracy and robustness with relatively limited input requirements. The model simulates crop growth in response to water availability, by keeping track of soil water balance with the conservative behaviour of biomass water productivity (WP). AquaCrop was adopted in the present study with the objective of identifying the potential growth and yield of Bambara groundnut (Vigna subterranean) landraces, which is an ancient grain legume grown, cooked, processed and traded mainly by subsistence women farmers in various agro-ecological regions in sub-Saharan Africa, and to evaluate the possibilities of transferring them to different locations. The simulations were aimed at the University Farm, Botswana College of Agriculture, Notwane, Botswana (24°33’S; 25°54’E, 994 m above sea level) experiencing a semi-arid climate for three landraces; ‘Uniswa Red’, ‘S19-3’ and ‘DipC’ which have originated from Swaziland, Namibia and Botswana respectively were used. The growth and yield performances of landraces were evaluated considering the landrace mean values for the site. On average, both ‘S19-3’ and ‘DipC’ reported 3.5 to 5% increase in biomass production, but with a 8% reduction in ‘Uniswa Red’. Similarly ‘S19-3’ and ‘DipC’ produced 4-7% higher pod yield compared to the mean value whilst it was 12% less in ‘Uniswa Red’. Simulation results indicated that under rainfed conditions in Botswana, two landraces, ‘S19-3’ and ‘DipC’ which originated from hot and dry climates in Namibia and Botswana respectively, reported a greater WP compared to the Swaziland landrace, ‘Uniswa Red’, which originates from a cooler, wetter climate. These differences can be tentatively attributed to the agro-ecological adaptation of landraces. This preliminary analysis indicates that AquaCrop can be successfully applied to assess the WP of Bambara groundnut landraces for various agro-ecological regions across semi-arid Africa.
Karunaratne, A.S. and Azam-Ali, S. (2013). AQUACROP MODEL AS A TOOL TO DISCLOSE THE WATER PRODUCTIVITY OF BAMBARA GROUNDNUT LANDRACES FOR RAINFED FARMING IN BOTSWANA . Acta Hortic. 979, 401-406
DOI: 10.17660/ActaHortic.2013.979.43
https://doi.org/10.17660/ActaHortic.2013.979.43
biomass, yield, agro-ecological region, adaptation, modeling, 'Uniswa Red', 'S19-3', 'DipC'
English

Acta Horticulturae