Impact of Sweetpotato-maize Intercropping Spatial Arrangements on Yield and Economic Returns in a Humid Agroecosystem of South East Nigeria

Abstract

Two field experiments laid out in a randomized complete block design were carried out in 2019 and 2020 planting seasons at Umuahia, south eastern Nigeria to assess the effect of orange-fleshed sweetpotato variety and pro-vitamin A maize spatial arrangement on the productivity and economic returns of the intercropping systems. The treatments were fifteen (15) and comprised sole Umuspo1, sole Umuspo3 and sole Umuspo4 sweetpotato varieties, sole maize at 1 x 1m, 4 plants/stand, 1x 0.5m, 2plants/stand and 1 x 0.25m 1plant/stand spatial arrangements and Umuspo1, Umuspo 3 and Umuspo 4 mixed with maize at the three spatial arrangements. Results revealed that sole Umuspo 3 sweetpotato had comparable root yield with sole Umuspo1 and intercropped Umuspo 3 but significantly higher yield than Umuspo 4 in both cropping system and intercropped Umuspo1 regardless of maize spatial arrangement. There were yield advantages of growing the sweetpotao varieties and maize together but the highest yield advantage as depicted by LER, ATER and LEC was obtained from the sweetpotato varieties intercropped with maize at 1 x1m, 4 plants/stand spacing pattern. However, the highest profit (net monetary returns) was from Umuspo3 orange-fleshed sweetpotato mixed with maize at 1 x 0.5 spacing, 2 plants/stand spatial arrangement. In all, intercropping Umuspo 3 Variety with maize at 1x0.5 spacing 2 plants/stand arrangement resulted in good use of land and the highest profit and is recommended to give farmers meaningful yield gains and profit from the two nutrients crops, having diets rich in vitamin A.