Productivity, land–use efficiency and competition in bread wheat-sweet lupine intercropping system under additive series in Northwest Ethiopia

Food production on continuously declining agricultural land to feed the ever-increasing population is a severe issue in Ethiopia. The present study was therefore initiated to evaluate inter and intra-row spacing on yield performance, land-use efficiency and competition in bread wheat-sweet lupine additive series intercropping system. Field experiments were conducted for 2 years in Adet and Debre Tabor experimental sites. The treatments consisted of three inter-rows spacing and 3 intra-rows spacing of sweet lupine. Moreover, the sole crop of wheat and lupine were also included as controls. The experiments were laid out in a factorial randomized complete block design with three replications. The results showed that the combination of 20 cm inter-row spacing with 10 cm intra-row spacing of sweet lupine in bread wheat-sweet lupine intercropping system gave the highest total yield of 4.36 t ha-1 and 4.75 t ha-1 at Adet and Debre Tabor respectively; the land equivalent ratio of 1.43 and 1.57 at Adet and Debre Tabor respectively. System productivity index of 4.96 and 5.88 at Adet and Debre Tabor respectively. Gross monetary value of 2511.26 and 2752.19 USD ha-1 at Adet and Debre Tabor experimental sites respectively. Gross monetary value was generally higher for intercrops than sole cropping systems in both locations; it is linked to intercropping yield and economic benefits compared to sole cropping. Farmers in the study area and areas with similar agroecology are recommended to intercrop sweet lupine with bread wheat at 20 cm inter-row spacing with 10 cm intra-row spacing of sweet lupine.