The region covers the central part of Zambia extending from east to west. It is subdivided into a sub-region Ha comprising the sandveld plateau of Central, Eastern, Lusaka and Southern Provinces and a sub region lib comprising the Kalahari sand plateau and the Zambezi flood plains in Western Province. The general elevation is between 900 to 1300 metres above sea level.
This region receives medium annual rainfall of between 800 and 1000 mm. Rainfall is generally well distributed and the length of the growing season at 70% probability ranges from 100 to 140 days. The growing season may, however, contain one to three 10-day dry periods of less than 30 mm rainfall. These can significantly reduce crop yields especially on sandy soils. However, in normal years the climatic conditions are very favourable and together with the generally good soils make the region the most productive.
Mean daily temperatures during the growing season range from 23