Abstract

Ahmed Nur Osman, Anders Ræbild, Jørgen Lindskrog Christiansen3 and Jules Bayala

In agroforestry systems, crop yields under trees are often low compared to outside. This study explored crop management under trees for improved production and income for farmers. Cowpea (Vigna unguiculata) and pearl millet (Pennisetum glaucum) sole and intercrops were grown under and outside the shade of six randomly selected Parkia biglobosa trees during one season in south-central Burkina Faso. The area under the canopy of each tree was divided into four main plots according to cardinal directions, and sub-divided into three concentric zones. Control plots were established outside the tree canopy. The crops were intercropped in two different proportions using the replacement method and compared to sole crops. Days to flowering were noted and yields were measured, and Land Equivalent Ratio (LER) and Monetary Advantage Index (MAI) calculated. Flowering was earlier outside than under the trees and intercrops flowered earlier than sole crops. Cowpea sole crops had significant grain yield losses of up to 21% under trees compared to outside, and pearl millet yield was reduced up to 67% under trees. Intercrop yields were less affected by growth under trees. LER was significantly higher under the trees than outside, and were always larger than unity indicating benefits of intercropping over sole cropping. Intercropping with two rows of cowpea and one row of millet gave significantly higher economic benefit than mixture with one row of each of the crops. Results indicate that intercropping could improve the system’s productivity, increase the income for farmers, and compensate losses in pearl millet under the canopy.