Specific Problems of Semi-Arid Environments

Abstract

A precise definition of what constitutes a semi-arid environment is difficult, but it is generally agreed that the fundamental cause of aridity is climatic. While the major climatic factor involved is the total amount of rainfall per annum, its effectiveness depends on monthly distribution, the potential evaporation rate, the soil moisture infiltration rate and the vegetative cover. Pragmatically, a semi-arid environment can be defined as one in which the effective precipitation is too small for the successful practice of continuous crop production without irrigation water, but sufficient for the seasonal growth of forage and for limited animal production.