Sulphur, zinc, and boron deficiencies in the Dedza Hills and Thiwi-Lifidzi regions of Malawi


  • J.W. Wendt The Rockefeller Foundation, New York, U.S.A.
  • Jan Rijpma Food and Agriculture Organization of the U.N., Rome, Italy


Boron, Maize, Plant zinc, Sulfur, Malawi


Low maize (Zea mays L.) yields are common in the Dedza Hills and Thiwi-Lifidzi Rural Development Projects (RDPs) of Malawi. This study was undertaken to determine if deficiencies of minor nutrients could be reducing yields. "Missing nutrients" trials conducted during the 1990- 91 and 1991-92 growing seasons showed substantial yield responses to S, Zn, and B applications. Tissue analysis indicated that Zn-deficient maize ear leaves had high Fe:Zn ratios, but not low Zn concentrations per se. In 1992, soil samples from 105 farmer sites scattered throughout the Dedza Hills and Thiwi-Lifidzi RDPs indicated widespread S, Zn, and B deficiencies. A nutrient supplement to the standard N and P fertilizers containing S, Zn, and B was applied to 79 farmer sites. The supplement improved yields by an average of more than 1160 kg ha-1 in the region primarily in the Dedza Hills, and 390 kg ha-1 at sites principally in the Thiwi-Lifidzi area. Poor correlation existed between yield and soil analytical results. Evidence is presented that suggests that yield improvements were due primarily to application of Zn and (or) B.



Research Papers