Working Document Series Open Access Effects of tied ridges for rainwater harvesting on maize yields in Swaziland O. T. Edje · E.M. Ossom This study assessed options for use of tied-ridges for on-farm water harvesting in Swaziland. Results showed that farmers in sandy and loamy soils need different sizes of ridges, 4 m and 2 m, respectively. RUF-34582 2010 CC BY 4.0 8 Sep 2015