Evaluation of sorghum stover and tree leaf mulches for sustainable maize, sorghum and sunflower cropping in a semi-arid region of Zimbabwe

The effect of sorghum stover and tree leaf mulches on seed yields and yield components of maize (Zea mays L.), sorghum (Sorghum bicolor L.), and sunflower (Helianthus annus L.) crops in tied ridges were studied under rainfed conditions at Chiredzi Research Station in 1993/94 and 1994/95 seasons. Mulching significantly increased maize seed and stover yields by 26% in 1993/94 and showed some improvement in total soil water content and water use efficiency over the control treatment in 1994/95 season. Seed yield of sunflower was significantly correlated (r=0.55) to cumulative soil water content in 1994/95. Stover yield for sunflower was significantly correlated (r=0.60) to cumulative soil water content in 1994/95. The results from this study suggest that sorghum stover and dry tree leaf mulches had significant beneficial effects on maize performance in a year with good and well distributed rainfall whereas for sorghum and sunflower, the benefits were higher in the drier year.