Dryland Agriculture Glossary

Abstract

Dryland farming antedates history, but Hegde (1995) stated that the use of the term in its present form and meaning probably began in Utah, the United States of America, around 1863 and credits John A. Widstoe as being the pioneer of dryland farming research. According to Hegde, Widstoe defined dry farming as “the profitable production of useful crops without irrigation on lands that receive rainfall of less than 500 mm annually”, and said that the definition could be extended to include areas receiving up to 750 mm annual rainfall where its distribution was unfavourable. It is important to note that this definition is limited to land where crops are grown and does not include the management of other lands in dryland regions. Mathews and Cole (1938) broadened the definition by suggesting that dry farming is concerned with all phases of land use under semi-arid conditions. Not only the question how to farm but also how much to farm and whether to farm or not must be taken into consideration. These questions raised by Mathews and Cole are critical regarding whether or not dryland agriculture can be sustained in the long term. However, they have not received the attention they deserve. Hargreaves (1957) defined dry farming as agriculture without irrigation in regions of scanty precipitation. Oram (1980) made the distinction between rainfed farming and dryland agriculture explicit. He defined dryland agriculture as husbandry under conditions of moderate to severe moisture stress during a substantial part of the year, which requires special cultural techniques and crops and farming systems adapted for successful and stable agricultural production. Such conditions generally occur in regions classified as semi-arid or arid. Pastoral systems are an important part of dryland agriculture, and constitute the sole form of agricultural use in some areas, particularly in arid regions. Stewart and Burnett (1987) added that dryland farming emphasizes water conservation in all practices throughout the year. The Australian Centre for International Agricultural Research (2002) considers dryland cropping to occur in areas where the average water supply to the crop limits yield to less than 40 percent of full (not water-limited) potential. On this basis, it estimates that one-quarter of the world’s cereal production is from dryland agriculture.