1.5 Choose the proper definition from the right column

Soil heavy, productive, acid, chemically, wet

Condition acid, acidity, alkaline, neutral, natural

Concentration high, solid, organic, low, absorbing

1.6 Translate the following words having the same stem.

Check your translation with the help of a dictionary

To vary, varying, variation, variant, variable, variability.

1.7 Answer the following questions

1. Why do soils vary greatly in their chemical make-up? What is it due to?

2. What elements are the most abundant in the soil?

3. What elements are referred to as “fertilizing elements”?

4. What is “acidity” of soil?

5. What is “alkalinity” of soil?

6. What is neutral soil?

7. What is pH value?

8. What kind of soil can we find in humid climates?

9. What should you do if soil is acid?

1.8 Explain the meaning of the symbol “ph”.

1.9 Explain the terms “acid soils” and “alkaline soils” in English.

1.10 Read the following text and briefly retell it. Plant Foods in the Soil.

All the main plan foods are found in a normal soil. Some of each plant food is there in such a form them the plant can use it. This is known as available plant food. Some more of it is in a form which the plant cannot use at the moment. Such plant food is said to be unavailable. To become available it may need to be changed chemically in some way.

Trace elements, the other plant foods which are needed in very small quantities, are found naturally in most soils. Sometimes one particular plant food is short and this deficiency can cause damage to crops, livestock or both.

Text 2 Organic Matter in the Soil

2.1 Read the following international words and translate them: productivity, production, physically, effect, function, chemical, minerals, factor, tendency, absorption, control, location, limit.

2.2 Read the following words: judging, desirable, deny, successfully, essential, insufficient, capacity, generous, droughty, tight, improvement, abundant, therefore, particular, significance, fluctuate, measure, often.

2.3 Say it in Russian

Light-coloured soils, a coat of protection, artificial fertilizers, acid products, parent rock, rate of absorption, air circulation, the early stages of plant growth, root development, tangled mass, water runoff, A-horizon.

2.4 Translate the following sentences; pay attention to the grammar

1. Farmers in all ages have used the colour of a soil to assist in judging its productivity: the darker the soil the more organic matter content and the more desirable it was for crop production.

2. No one can deny that plants can be grown successfully without organic matter.

3. For any given soil in any given location, the organic matter content fluctuates between relatively narrow limits.

2.5 Read and translate the text with a dictionary

F armers in all ages have used the colour of a soil to assist in judging its productivity: the darker the soil the more organic matter content and the more desirable it was for crop production. Even today, dark-coloured soils are usually considered more productive than light-coloured ones. Undecomposed organic matter aids in crop production by acting physically to provide a coat of protection against heat and cold and against the effect of beating raindrops.

No one can deny that plants can be grown successfully without organic matter. But everyone will agree that the most efficient way to grow plants is in a productive soil rich in fresh, decomposing organic matter.

Organic matter has many functions in the soils. Some of the essential nutrients for plant growth come directly from organic matter .Where it is insufficient artificial fertilizers must be used to supplement it .Organic material contributes chemical constituents to soil water largely in the form of acid products. These chemicals perform several functions, but perhaps the most important is to break down some of the minerals of the parent rock, making them available to plants.

Organic matter is an important factor in the water capacity and rate of absorption of some soil .Often droughty soil are greatly improved by generous addition of organic matter. Tight soils with poor air circulation show marked improvement when organic matter is added. This is particularly important in the early stages of plant growth, at the time of seed germination and early root development. Soil with abundant organic matter shows little tendency to form crusts when they dry out after rains; therefore, the young tender plants have little difficulty in breaking through the surface. In cultivated soils organic matter is an important factor of tillage. Not only does it contribute to the ease of cultivation, but it also reduces the delay of tillage after rains.

Organic matter reduces soil erosion. This is of particular significance where abundant undecomposed material remains on the surface and where plant roots form a tangled mass in the A horizon. Decomposed organic matter, or humus, also tends to bind together soil mineral particles, induce water absorption, check the rate of water runoff, and reduce the removal of surface soil particles by wind. Proper management and control of organic matter is one of the best means of preventing both water and wind erosion.

For any given soil in any given location, the organic matter content fluctuates between relatively narrow limits. Thus if a farmed soil contains 3 per cent organic matter under normal management, this can be reduce to possibly2 1\2 per cent by poor management, and it can be raised to possibly 3 1\2 per cent by good management. The amount of organic matter in any soil tends to fluctuate over a range of about 1 per cent. Only by exceptional measures, such as annual applications of large amounts of manure, can this soil’s content of organic matter be raised above 3 1\2 per cent, and only by very drastic means, such as excessive cultivation without the use of animal manures or green manures, can it be reduced below the 2 1\2 per cent level.