Maize-orange-fleshed sweetpotato intercropping: potential for use to enhance food security and scaling-up the nutrition effort in Malawi.

Abstract

Abstract Maize is the staple food in Malawi where it is mainly cultivated by smallholder farmers under rainfed conditions. Due to increasing climatic uncertainty and declining soil fertility, crop failures often result in shortages affecting up to 1.6 million people every year. An estimated 47% of the children in Malawi suffer from stunted growth because of under-nutrition, and are vulnerable to illnesses and learning difficulties. Crop diversification is at the core of Malawi's agriculture policy. The Rooting out Hunger in Malawi with Nutritious Orange-fleshed Sweetpotato (OFSP) project, funded by Irish Aid, has been working with partners since 2009 in Malawi to popularize this type of sweetpotato. The potential of the OFSP cultivar Zondeni to contribute to sustainable intensification of a maize-based cropping system as an intercrop was investigated. Maize-sweetpotato intercropping trials were conducted in two consecutive rainy seasons/years at Bvumbwe Agriculture Research Station in southern Malawi. Four spatial arrangements were compared (two rows OFSP: one row maize; one row OFSP: one row maize; one row OFSP: two rows maize; and three OFSP: one maize plant within the same row) in large plots. Trials, each with three replications, were repeated each year, with maize harvested at 4 months and OFSP harvested at 5, 6 and 7 months after planting. In year 2, land equivalent ratios (LER) were determined, while in both years farmers' assessment of trial performance were obtained, and gross margin analysis were determined. Gross margin analysis indicated that OFSP-maize intercropping was highly profitable in both years, with sweetpotato accounting for greater than 90% of the income. Yields were much lower in the second year compared with the first, and considered to be more representative of on-farm yields in Malawi. In this trial, LER was 1.79 over all spatial arrangements, indicating the high potential of OFSP-maize intercropping to contribute towards sustainable intensification in Malawi. Farmers' rank preferences for OFSP-maize spatial arrangements changed between year 1 and year 2, with the higher OFSP-density (two rows OFSP: one row maize) arrangement preferred in year 2. The marked absence of sweetpotato weevil damage on sweetpotato in the OFSP-maize intercrops was noted in both years. Results are discussed and recommendations made for future testing and dissemination of OFSP-maize intercropping in Malawi.