Effect of climate variability on net irrigation requirements of grain maize (Zea mays [L.]) and winter wheat (Triticum aestivum [L.]) based on long-term climate data: the case of Kadoma, north-west Zimbabwe.

摘要

Average climatic data values of past records of twenty continuous year periods are routinely used in Zimbabwe to determine the crop net irrigation requirements in irrigation systems design protocols with little or no regard for climate variability. Using the case of Msengezi Village 6 Irrigation Scheme (northwest Zimbabwe) designed in 2007 using climate data of the period 1959-1978, this study was conducted to assess the effect of climate variability on the water requirements, effective dependable rainfall and net irrigation requirements of grain maize and winter wheat. Later climate data of the periods 1967-86, 1977- 96 and 1987-2006 was used. The water requirements and net irrigation requirements of spring wheat computed using average climatic data for the three different periods had no significant difference (p