ABSTRACT
The main objective of dry farming is to use natural rainfall to grow crops. This can only be achieved if the crops can tolerate very dry conditions and if measures are taken to capture and keep any rainfall in the soil itself. Some soils (e.g. clays) retain the water very well. Other soils are ‘droughty’ because the rain easily drains through them according to the soil texture and structure. If the surface has a seal on it, a thin crust is formed, usually made of fine elements, which reduces evaporation of the water from the soil surface and encourages runoff. Organic matter improves the water-holding capacity of soils, so sewage or kitchen waste applied to the soil may increase its capacity for producing a good yield of crop (see Box 18.2). In the Mediterranean, the traditional dry farming crops are cereals, such as the hard wheat grown in southern Italy for pasta production. Barley is even more tolerant of drought than wheat. In Portugal the government introduced a ‘wheat campaign’ to offset food shortage. This supported farmers by means of subsidies for the purchase of seeds, fertilizers and machinery. However, this approach had a serious impact on soil degradation that was officially recognized by the 1950s. The difficulties and hardships of this period in the Alentejo are beautifully described in A Portuguese Rural Society (Cutileiro, 1971).
