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Jawaharlal Nehru University (2002)

Technology transfer for dry land farming : a study of India and Israel

Singh, Krishan

Titre : Technology transfer for dry land farming : a study of India and Israel

Auteur : Singh, Krishan

Université de soutenance : Jawaharlal Nehru University

Grade : Doctor of Philosophy (PhD) 2002

Préface partielle
Raising of crops with irrigation is known as irrigated agriculture. When irrigation is not desigined and rain water is the only source of water for the survival and growth of crops, it is termed as rainfed agriculture or dryland agriculture (Barani). Although the terms rainfed and dryland agriculture are dubbed together, they are not synonymous. A distinction between the dryland and rainfed agriculture is possible depending upon the annual precipitation. Farming within the confines of regions with less than 750 mm. annual rainfall is called dryland agriculture, where as the one located in zones with more than 750 mm. annual rainfall is designated rainfed agriculture. In dryland regions, inter and intra-season oscillations in rainfall are unusually high . The rain water conservation in soil where it falls is necessary to moderate the effect of drought-like conditions that often develop between two rain events. In continuation it is important to note that the term ’dry lands’ or ’arid lands’ is used to distinguish all those areas which experience regular water shortage on a seasonal or longer term basis. Thus it includes not only the arid lands of the world, defined by their extremely low precipitation totals, but also encompasses those regions which may record significant rainfall for at least part of the year. In the arid zone, rainfall is the major control of land use as many activities are carried out close to their minimal water requirements. Hence, even small rainfall fluctuations can produce major effects on the crop growth and the animal survival. As rainfall decreases from the humid tropics towards the semi-arid zone, the chances of crop failure increases, until below about 250 mm per annum, successful cultivation is not really possible on a long-term basis. Along this same gradient the importance of irrigation increases. Thus there may be two implications of dryland agriculture : 1. The term dryland agriculture may simply mean rainfed agriculture. In that case even those areas which are located in most of the areas where agriculture is largely rainfed may be regarded as regions of dry land agriculture. 2. Another implication of dryland agriculture is that, it may apply only to such regions where the environment is really dry with a limited amount of rainfall, an absence of irrigation, and where only such crops are grown which are adapted to dry conditions. In this kind of implication, it is imperative to set a climatic limit to such regions in terms of particular isohyet or a certain figure of. water balance. Thus dryland agriculture is that of not only rainfed agriculture but also of an arid and semi arid environment.

Présentation et version intégrale (Shodhganga)

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