Production and energy-use efficiency of greater yam (Dioscorea a1ata)-based intercropping system as influenced by intercrops and planting patterns

Abstract

A field experiment was conducted at Bhubaneshwar during 2001-02 and 2002-03 on acid laterite soils under rainfed conditions, to assess the production and energy-use efficiency of various greater yam (Dioscorea alata) based intercropping systems. Greater yam was planted at normal (90 x 90 cm), paired (601120 x 90 cm) and skipped rows (901180 x 90 cm) with 1,2 and 3 rows of maize (Zea mays L.), sorghum [Sorghum bicolor (L.) Moench] and pigeonpea [Cajanus cajan (L.) Millsp.] respectively as intercrop. Sole greater yam was planted as control. The maximum tuber-equivalent yield (18.7 tlha), land-equivalent ratio (1.37) and production efficiency (89.2 kglhalday) were obtained with maize as an intercrop in greater yam (normal planting), followed by greater yam (paired row planting). Pigeonpea and sorghum were the next best intercrops in the order. Similarly, intercrop- ping with normal row and paired row planting irrespective of intercrops produced higher output energy (84.25- 100.70 x 103 MJlha). Skipped row planting, due to lower greater yam tuber yield, recorded lower tuber-equivalent yield, land-equivalent ratio, production efficiency and energy output than sole greater yam cropping. However, en- ergy output : input ratio and energy-use efficiency of greater yam + pigeonpea in skipped row planting was highest due to its lowest seed as well as manures and fertilizers energy inputs. Greater yam + maize (normal row planting) intercropping system was the next best in energy output : input ratio due to higher energy from the yields. Thus, maize was the best intercrop (1 row) with greater yam planted at normal rows (90 cm x 90 cm).