§ 53. Soils (textbook)

§ 53. Soils

 

1. What at first glance, the soil?

2. What do the grounds for a person?

 

Formation of soil. Earth called the nurse. That it makes a special life-giving layer - the soil. Soil soil called top loose layer of fertile earth's crust. Fertility -  the ability to provide plant nutrients.

Soil formed as a result of complex interactions of rocks, climate, surface water, plants and animals. Rocks are the basis for forming soil and determine its composition. Climate determines the presence of heat and it moisture. Many animals that live in soil - worms, beetles, ants and  animals (moles) - weeds and improve penetration of water in it and air. And organisms decompose plant remains and form humus (humus). It is in humus contains substances essential for power plants. Because of its amount depends on soil fertility: the greater humus layer, the rodyuchishyy soil, thus increasing the yield of agricultural cultures.

Soil formed centuries. With dense vegetation and under favorable climatic conditions for the soil layer 1-2 cm thick takes approximately 500 years. To imagine the complexity of this process can provide such a simplified ground formula: (rocks humus water air) x time = soil. Lo why call a special natural soil formation.

Distribution of soils. Soils almost universally covered land. They are very diverse, as are formed by different environmental conditions. However, in their distribution patterns are: soils vary from the equator to the poles, and the mountains - from the bottom to the top.

In equatorial latitudes in hot and humid climate prevalent red and yellow soil and chervonozemy. Bright red color makes them great iron content. In these conditions, abundant precipitation wash away nutrients, such as marginal soils. In subtropical latitudes in the hot and dry climate during disperse desert vegetation formed gray-brown desert soils. Humus content in them is limited, so they are marginal. Often saline.

Chestnut soils formed also in arid climates, but in temperate latitudes in grassy vegetation. Humus content in them is low, but they sprinkled enough fertile. Black earth  soils temperate latitudes. It - most fruitful soils in the world. They formed in a slightly arid climate in the rich grassy steppe vegetation. A layer of humus in which over 1 m. These soils are common in Ukraine and is its immense wealth. Podzolic soils also common in temperate latitudes, but they are formed by forests with sufficient moistening. So  nutrients leached to depth.

Tundra soils hleyevi formed sub-Arctic latitudes, in cold climates and permanent wetlands. They have the wetlands layer, called hleyevym. Arctic soils popular islands in arctic latitudes. They formed in cold, dry climate and permafrost in the poor vegetation. The content of humus in them quite small.

Impact human activities on soil. Soils - It is our wealth for ever. It is more expensive than coal, oil and gold. Formed soil, as you know, very slowly. And it can destroy the very quickly.

The destruction and impoverishment of the soil may lead wrong soil. This in turn may promote the natural destructive processes, like blowing the top fertile layer and wash it surface waters. Major threat to soil are ravines that seem, "leaves" eating away the land. 

Protection soil is Proper maintenance of agriculture. Slopes to plow across the water could not drain and longitudinal furrows wash away the fertile layer. Chemical fertilizers and pesticides, which in excessive number may pollute the soil should be used wisely, in moderation. Planting strips greenbelts prevent wind erosion by wind. Stop growth ravines possible by planting  their slopes bushes and trees.

 Soils are not declared monuments of nature. But if we look at the ordinary black earth, which generates all the colors of the world, will understand its greatness and beauty.

 

Questions and Tasks

1. What is soil? How is it formed?

2. How old to work naturally to create a layer of soil in 1 cm?

3. Why on Earth form different types of soil? How do they apply?

4. How can I protect soils from damage and depletion?

5. What common ground in your community? Are they fertile?