a. Dry rangelands in semi-desert zones.
The predominant controlling factor for such lands, is the limited amount of annual rainfall and the uncertainty as to when it will occur. There is little or no crop production in this zone, except where localized irrigation from shallow wells is feasible. Much of the land fed by natural rainfall is partially occupied by forage and browse plants, with open ground between plant clumps. After a period of showers, this open around may be occupied briefly by short-season annuals, that quickly produce seed and die. The total amount of palatable forage for livestock is usually quite limited, but is greatest on areas of permeable soils on which runoff of rainfall is not rapid, and there is opportunity for rains to infiltrate into the soil profile where much of it is stored for subsequent uptake by plant roots.
Most of the rangelands in regions of limited and uncertain rainfall are not now being managed to fully develop their potential for producing forage and supporting livestock enterprises. Too often there is severe and ruinous competition between herdsmen for limited supplies of forage and water, during relatively short grazing seasons. Such a situation is not conducive to learning the principles of rangeland and livestock management by trial and error. This may explain the almost universal overgrazing, caused by overstocking the rangelands, which severely damages the vegetation and the soils, particularly in semi-desert regions in periods of protracted drought.
The pity of such damaged rangeland is that recovery is very slow even when grazing pressure is reduced, and the real potential for support of livestock is never allowed to develop.
It is probable that the vast areas of drought plagued lands of Africa, the Near and Middle East and elsewhere could be made continuously far more productive than it has been In recent decades; and that methods of cushioning against recurring droughts can be made effective. These management principles will be detailed in a later section of this report. The implementation of basic principles must be compatible with the social, economic and political situation In each country, with such adjustments as will permit full exploitation of climatic conditions, land and soil capabilities, the strengthening of plant growth, and the reduction of unnecessary runoff of precious rainfall. However, a first step would be recognition of the basic principles of managing the natural resources, and the rewards that will follow prudent management. Changes in social, economic, and political policies may be feasible once the economic benefits of improved management become visible.