Evaluating Sorghum bicolor (L.) Moench (Sorghum) Vigour at Juvenile Stage in Agroforestry Parklands Systems According to a Climatic Gradient in Burkina Faso (West Africa)

Agroforestry parklands, due to their dependency on rainfall remain vulnerable to climate change. This research assessed a rainfall gradient effect on sorghum height to evaluate its vigour for formulating recommendations to maintain and/or improve crop productivity in agroforestry parklands under climate change. Studied agroforestry parklands consisted of an association of Sorghum with Vittelaria paradoxa C. F Gaertn (Karite) and Parkia biglobosa (Jacq.) Benth (Nere) at sites located in Burkina Faso’s three climatic zones. Sorghum height was higher at lower rainfall. Higher sorghum height was associated with Karite at all the studied sites. It was higher at low rainfall for both tree species. Sorghum height increased from the zone under canopies to outside canopies associated with both tree species. For all zones, sorghum height was higher in association with Karite. The lowest sorghum height was in the first zone under canopies at all the studied sites, while for all zones, sorghum height was higher at low rainfall. The sorghum growth rate was higher in association with Karite, lower in the first zone under canopies and higher at low rainfall. The sorghum growth rate increased with the increase in the number of days after sowing at all the sites, in all the zones and under both tree species. The risk of sorghum production loss could be important in agroforestry parklands under high rainfall due to reduced vigour, and this risk could be reduced under low rainfall. Promoting Karite in agroforestry parklands could enhance sorghum vigour and reduce the risk of sorghum production loss under climate change in the Sahel. It could be recommended farmers avoid cultivating Sorghum in the zone nearest to the tree trunk in agroforestry parklands.