Implications of Associating Sweetpotato [Ipomoea batatas (L.) Lam.]with Different Groundnut (Arachis hypogaea L.) Populations on Tuber Yield and Soil and Tuber Chemical Properties

摘要

Sweetpotato [Ipomoea batatas (L.) Lam.] is a storage root crop commonly cultivated in Southern Africa; groundnut (Arachis hypogaea L.) is a popular grain legume that is also commonly grown in the same region. An experiment was carried out in 2006-2007cropping season, to determine the effects that intercropping a fixed plant population of Sweetpotato with varying groundnut (peanut) populations, could have on the chemical properties of the soil and Sweetpotato tubers. Results showed no significant differences among soil chemical properties (except total nitrogen, with a range of 0.091-0.106%); macronutrient concentrations in tubers showed no significant differences. Among the micronutrients, only boron concentrations were significantly (P < 0.05) higher in monocropped Sweetpotato (7.333 mg kg~(-1)) and lower (6.006 mg kg~(-1)) when sweetpotato (33,000 plants ha~(-1)) was intercropped with 100,000 plants ha~(-1) of groundnut. Tuber yields showed 54% increase under a groundnut population density of 66,667 plants ha~(-1). Small-scale farmers are encouraged to intercrop sweetpotato with 66,667 plants ha~(-1) of groundnut.