Assessing the productivity and profitability of yam-based intercropping systems in the northern Guinea Savanna zone of Ghana.

A field experiment was conducted during the wet seasons of2001 and 2002 at the Savanna Agricultural Research Institute (SARI) Tamale, Ghana to assess the productivity and profitability of various yam-based, intercropping systems. The results showed that except cowpea, grain yield of monocropping, were higher than that of intercropping. Monocropping yam yields were higher than intercropping yam except yam/maize and yam/cowpea intercropping. Leaf area index of the minor crops and yam were not significantly affected by intercropping arrangement. The monocropping recorded higher harvest index than intercropping. The yam/cowpea intercropping recorded land equivalent ratio (LER) and area x time equivalent ratio (ATER) of 2.12 and 1.47, respectively, was more productive th^n all the intercropping arrangement. The yam/maize intercropping was more profitable in terms of monetary advantage (MA) than the other intercropping arrangement. The yam/maize intercropping recorded the highest system productivity index (SPI') value of8246.0 kg/ha and yam/soybean intercropping recorded the lowest SPI value of 3615.0 kg/ha. However, based on LER, ATER, SPI and MA, cowpea and maize are recommended as the most productive and profitable minor crops in yam-based cropping systems in the northern Guinea Savanna Agroecological zone of Ghana.