1. All land is utilized for arable and livestock farming, the area under forests being only 0.02 ha per head of the population in the Netherlands.
2. The direction and speed of water movement and the soil's holding capacity must be taken into account when considering and planning subsurface irrigation systems.
3. The water vapour being cooled, precipitation takes place.
4. Kerosene is the fuel used in jet engines.
IV
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1. If she had all the necessary materials, she would certainly finish her work in time.
2. The farmer would plow, plant and harvest faster easier and more profitably if he had efficient power.
3. If a crop is growing under conditions of a single nutrient deficiency, the addition of appropriate fertilizer will give an increase in yield.
V "Land Resources for Farming". :
1. What do differences in productivity of land resources result in?
2. What is the main task of agriculture?
Resources for Farming
Our country has 22275 million land hectares of land resources and only 27 per cent (about 601,4 mln ha) have characteristics for agricultural production. Land resources for farming must have soils sufficiently retentive. They must be level enough to allow the use of machinery. The climatic conditions are to be good enough for crop production. The extent of agricultural land is not fixed. It changes as new techniques are discovered.
It was, for instance, impractical to cultivate low yield virgin lands where were no large machines. Land with infertile but physically favourable soils have become more valuable when large tractors and other machines had appeared. Better sources of power have made irrigation practical in places where formerly it was impractical. Nevertheless differences in productive capacity of land resources are tremendous. On the desert we can produce almost nothing, on some lands that have plentiful water, productive soils good location in relation to industrial centres we can produce several thousand roubles worth of products from a hectare in a single year. So the general principle is each hectare of land should be given to the use in which its economic productivity is the highest. The main task is to raise productivity of our land resources.
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I , , , , .
1. The data of the land productivity are quite necessary to determine the rate of taxation and for proper land use management.
2. To conserve land is the main task of all generations present and future.
3. Soil water is a very significant factor in planting, tilling and harvesting cultivated crops.
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4. A very efficient way of conveying and distributing irrigation water is by means of pipe-lines.
5. Sometimes, the source of water may be lower than the area to be irrigated.
6. Diverting water from the flowing rivers and streams is the oldest known practice of obtaining water for irrigating cultivated crops.
II , . , , , .
1. Per capita use of water has been found to increase rapidly in future.
2. This crop appears to be fully developed in all areas of the United States.
3. The soil is said to be at field capacity when after good watering of the soil the deep percolation flow has virtually ceased.
4. We expect a lot of water uses of plants to be found in the nearest future.
5. We know plants to provide us with food, clothing, shelter and many other necessary things.
6. The farmers consider irrigation to be an important practice in arid regions where the annual rainfall is very low.
