Land improvement in the ussr

The Food Programme provides for a considerable increase in the output of foodstuffs and agricultural raw materials for the consumer goods industry. Significantly, the five-year plan of economic and social development for 1981-85 has no section on agriculture as has been the case in all previous plans. Instead it contains a chapter on the development of the agrarian-industrial complex. This includes agriculture with such related sectors as land improvement, the production of fertilizer and machinery, as well as the food processing and concentrated feed industries, etc. This is done to improve coordination and economic ties among industries, to balance their development, to organize cooperation in raising the output of farm produce, and to improve its storage transpor­tation and sale.

To realize such plans farm crop yields should considerably grow, but crop farming is unreliable, being too often depen­dent on the weather. Only one per cent of ploughland receives sufficient precipitation and over half of it is in the so-called high-risk farming zone, where the summer is too short but droughts occur frequently and where periods of insufficient sunshine alternate with periods of insufficient moisture. The country's main grain producers — the Ukraine, the Volga area, and Kazakhstan—suffer from lack of moisture. Once in three or four years, or even more frequently, drought hits extensive areas.

After 1917 large irrigation systems were built to reclaim arid lands. Irrigation of more than 450,000 hectares of land has been completed in the Hungry Steppe in Uzbekistan, the hottest and driest semi-desert of the Soviet Union. New state farms set up there give today large quantities of meat, milk, grain, silk cocoons, melons, watermelons, vegetables and grapes.

The bioclimatic potential of the crop farming area of the IISSR is half of the United States or Western Europe. However the Soviet Union grows more sugar beet, sunflower, flax and potatoes and produces more milk and wool than the USA. Despite unfavourable natural and climatic conditions for farming, per capita agricultural output in the USSR has been steadily rising thanks to land reclamation work.

Land improvement is of vital importance for further ag­ricultural development.

It is necessary to raise the effectiveness of the use of both irrigated and drained land and to reduce the time re­quired for the realization of projected crop productivity on them.

Rational use of water for agricultural needs is also sig­nificant. Preparatory work for channelling part of the flow of northern rivers to the Volga basin is to begin, and simulta­neously research will go on to channel part of the flow of Siberian rivers to Central Asia and Kazakhstan. Thus, much more water will be supplied to pasture-land in desert areas.

The supply of water

'The total amount of water contained in our planet is con­stant and invariable and can neither be increased nor dimin­ished. It assumes a variety of forms, such as the oceans, mois­ture vapour, fresh water, lake water of varying degrees of salinity, and ice. As most of this water is locked away in the oceans, in snow fields, ice caps and glaciers, only a small proportion is available in a form readily usable by man More­over, a great deal of the water in and on the land is polluted by minerals or by industrial waste and so frequently rendered unusable

«Of the water contained in the oceans, a very small propor­tion daily changes its form and composition and is moved to the land, where it can be used by man and from where it returns to the oceans. This process, which has no beginning and no end, is known as the hydrologic cycle. It comprises a gigantic system operating in and on the land and oceans of the earth and in the atmosphere surrounding it/It is estimat­ed that something like 80,000 cubic miles of water are evap­orated each year from the oceans, together with approxi­mately 15,000 cubic miles of water evaporated from the lakes, rivers, canals and land surfaces of the continents. This total global evaporation is exactly balanced by the total precipi­tation, of which approximately 24,000 cubic miles in the form of waterfall on the land surfaces and the rest on the oceans. This cyclical movement of water is divisible into three main stages. Firstly, solar radiation, acting upon the surface of the oceans, heats the surface layers and causes evaporation and the diffusion of water vapour upwards into the atmosphere. The water vapour, which at this stage-is pure, is then trans­ported great distances by the winds. During its movement across the oceans and over the land, it may become polluted in a variety of ways; by atmospheric dust, by particles of ra­dioactive material or by industrial and domestic smoke and

soot.

In the second stage of the cycle, the air masses contain­ing the water vapour are suddenly cooled: This cooling which may occur for a number of reasons, though primarily as a result of the air masses being forced to rise over high ground, causes condensation to take place and rain or snow to be precip­itated. Of this precipitation, some falls directly into the oceans, out of man's reach and. some is too heavily polluted to be usable. The third and final stage is that in which the water moves back, over and under the land, into the oceans, from which it came. Of the water which falls upon the land, some flows over the surface, some sinks into the soil, and some is taken up by the roots of vegetation to be used by plants and sub­sequently released into the atmosphere by transpiration^ If, for example, an average of thirty inches of rainfall reaches the land surface each year, approximately twenty-one inches will evaporate directly or be transpired by vegetation. Of the remaining nine inches, most will run directly to the oceans as surface runoff or permeate the rock materials beneath the surface to form underground water and, at a later stage, indirectly reach the oceans. Water which began in the oceans sooner or later returns to them. The only stage in the cycle at which man can, at present, intervene and make use of the water on a large scale is the third, and only then if the water is comparatively pure.