MODULE 5
Soil
The objectives of the module are:
- to talk about soil, its formation and composition;
- to revisit Passive constructions;
- to discuss the value of soil resources;
- to develop ideas into an essay: planning and drafting.
Part 1
| Pre-reading |
Ex. 5.1 Answer the following questions:
1) Is soil a renewable or a non-renewable resource?
2) What do you know about soil composition?
3) What do you think have been the effects of using pesticides and artificial fertilizers in modern farming?
Ex. 5.2 Match the words with their definitions:
 1 humus
| A to use up, empty until little or non remains |
| 2 species | B ground, earth, especially the upper layer of earth in which plants, trees, etc grow |
| 3 to deplete | C a mass of rock particles and humus from which plants obtain essential materials |
| 4 soil | D biological group having some common characteristics able to breed with each other but not with other groups |
| 5 residue | E a living organism without leaves or flowers growing on other plants and characterized by absence of chlorophyll |
| 6 fungus | F that which remains after a part is taken or used |
| Reading |
Ex. 5.3 Read the text to learn about soil composition and soil loss:
To understand the potential for feeding the world on a sustainable basis we need to know how soil is formed, how it is being lost, and what can be done to protect and rebuild good agricultural soil. With careful husbandry, soil can be replenished and renewed indefinitely. Many modern farming techniques deplete soil nutrients, however, and expose the soil to the erosive forces of wind and moving water. As a result, we are using this resource much faster than it is being replaced.
Building good soil is a slow process. Under the best circumstances, good topsoil accumulates at a rate of about 10 tons per hectare (2.5 acres) per year – enough soil to make a layer about 1 mm deep when spread over a hectare. Under poor conditions, it can make thousands of years to build that much soil. Perhaps one-third to one-half of the world’s current croplands is loosing topsoil faster than it is being replaced. In some of the worst spots, erosion carries away about 2.5 cm (1 in) of topsoil per year. With losses like that, agricultural production will soon begin to fall.
Most soil is about half mineral. The rest is air and water mixed with a little organic matter from plant and animal residue. The mineral particles are derived either from the underlying bedrock or from materials transported and deposited by glaciers, rivers, ocean currents, windstorms, or landslides. The weathering processes that break rocks down into soil particles are also of importance.
The organic content of` soil can range from nearly zero for pure sand, silt, or clay, to nearly 100 percent for peat or muck. Much of the organic material in soil is humus, a sticky, brown, insoluble residue from the bodies of dead plants and animals. Humus is much more important to soil quality than its proportion indicates. It gives soil its structure, a description of how the soil particles clump together. Humus coats mineral particles and hold them together. By binding particles in loose crumbs, humus gives the soil a spongy texture that holds water and nutrients needed by plant roots, and maintains the spaces through which delicate root hairs grow in search of sustenance.
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Without soil organisms, Earth would be covered with sterile mineral particles far different from the rich, living soil ecosystems on which we depend for most of our food. The activity of the myriad organisms living in the soil creates its structure, fertility, and tilth (structure suitable for tilling or cultivation).
Soil organisms usually stay close to the surface, but that thin living layer can contain thousands of species and billions of individual organisms per hectare. Algae, bacteria, and fungi flourish in the top few centimeters of soil. A single gram of soil (about a teaspoonful) can contain hundreds of millions of these microscopic cells. Algae and blue-green bacteria capture sunlight and make new organic compounds. Bacteria and fungi decompose organic detritus and recycle nutrients that plants can use for additional growth.
Soils are classified according to their structure and composition into orders, suborders, great groups, subgroups, families, and series. There are hundreds of thousands of specific types within this taxonomic system!
One of the main limitations to maintain current, high levels of agricultural production is loss of arable lands due to erosion, toxification, desertification, and conversion to non-agricultural uses. The Food and Agriculture Organization (FAO) of the United Nations estimates that total world cropland losses amount to an area equal in size to the United States and Mexico combined (11 million hectares or 27 million acres) every year. Conversion to nonagricultural uses – urbanization, highways, industrial sites, strip-mining, and abandonment of marginal farmland – is responsible for half that loss. Toxification by hazardous wastes, chemical spills, salinization of irrigated lands, misapplication of pesticides, or deposition of atmospheric pollutants makes about 2 million hectares (5 million acres) unusable each year. Desertification consumes some 1.25 million hectares of cropland and about 10 million hectares of rangeland per year. Finally, around 2 million hectares of cropland are abandoned each year because of severe erosion problems.
The damage that modern man has done to the soil by intensive farming methods is great. Another problem is salinization from excessive irrigation. But salinization is not entirely a problem of modern, high-technology agriculture. Our ancestors probably discovered irrigation about 5,500 years ago. The ancient Mesopotamians, who lived about 4,500 years ago, were enthusiastic farmers. They built extensive irrigation channels in river valleys to try to increase their crop yields. Unfortunately, this led to waterlogging and salinization of the soil. The yield of the staple crop, barley, fell dramatically and prolonged famine occurred. The people who survived the famine had to change their staple crop from barley to wheat, which tolerated the salty soil better.
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The problem of soil erosion has occurred ever since man began to destroy forests. There is geological evidence that a rapid increase in the rate of soil erosion occurred about 4,000 years ago in the northern European countries, particularly Britain, France and Germany. There was also an increase in silt deposits in rivers. The time of this change corresponds to the introduction of agriculture to Europe. The destruction of forests, together with ancient man’s agricultural methods, almost certainly caused this environmental damage.
| Comprehension |
Ex. 5.4 Answer the questions:
1) What do we need to know about soil to understand the potential for feeding the world?
2) Is building good soil a quick process? How long does it take to accumulate good topsoil?
3) Where are the soil mineral particles derived from?
4) What is humus?
5) Which soil organisms inhabit the top few centimeters of soil?
6) What are the soils classified into?
7) Why are we losing billions of metric tons of topsoil every year?
8) What does nonagricultural use stand for?
Ex. 5.5 Say true or false:
1) Soil is an essential nonrenewable resource.
2) Our existence on Earth depends on maintaining fertile, tillable soil for crops.
3) There are only a few soil types on the Earth.
4) Under the best conditions, soil can accumulate 5 mm deep per year.
5) Human-caused erosion prevents soil losses.
6) Ecologically inappropriate farming and grazing practices are largely responsible for the destruction of our precious soil resources.
| Lexis |
Ex 5.6 Give Russian equivalents for:
Sustainable development, careful husbandry, to deplete soil nutrients, under the best circumstances, under poor conditions, to accumulate at a rate of, plant and animal residue, a spongy texture, to make new organic compounds, insoluble residue, to recycle nutrients, taxonomic system, conversion to nonagricultural uses, to be responsible for the soil loss, hazardous wastes, chemical spills, misapplication of pesticides, to make unusable.
Ex. 5.7 Look at the two lists of words below. List A contains words and phrases taken from the text. In list B, there are synonyms for each of these words. Match words in A to an appropriate synonym in B, for example indicate – point to (N.B. List B contains more words than you need.):
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A B
husbandry not producing
to deplete 10,000 sq meters
an organism farming
a particle an acre
a hectare chemical plant food
to range from … to … to point to
to indicate failure to keep
by binding to vary between
a nutrient to empty
sterile to arrange
a fertilizer a small bit
due to a living being
a loss by holding together
serving as nourishment
because of
Ex. 5.8 Work with a partner. Make as many words as you can by adding prefixes (e.g. in/un/re) or suffixes (e.g. –al, –able, –tion, –ly, -ful) to the words below, e.g. care: careful, careless, carefully:
build fertile solve
agriculture active class
new live add
pollute compose grow
environment use
Ex. 5.9 Rearrange the words to form sentences:
1) Ecosystem, is, renewable, a, resource, a, soil, in, healthy.
2) Around, is, soil, everywhere, us.
3) Take, for, years, may, accumulation, it, thousands, of, soil.
4) Alternative, could, farming, be, many, in, methods, used.
5) Agricultural, are, resources, dramatically, present, depleting, soil, systems.
6) Most, long-term, threat, to, erosion, is, future, the, certain, soil, the.
Ex. 5.10 Read the text below and then decide which word best fits each space:
| Soil forms over thousands of years from weathering of rock. There are three types of weathering: physical weathering (where temperature changes (0)……. the rock to expand and contract until it shatters into pieces), chemical weathering (where carbon dioxide and water form a weak acid that (1)……. rocks such as limestone) and biological weathering (where the rock is broken down by the action of living things such as plant (2)……. and bacteria. The top layer of the soil (topsoil) is rich in humus – a dark, fibrous material formed from (3)……. organic matter. Humus contains microorganisms that break down the organic matter. Humus absorbs (4)……. and binds the inorganic particles together. The quality (or (5)…….) of soil depends on the amount of humus in it – the organic content. Good quality topsoil is dark, moist and crumbly. The middle layer of the soil (6)…….. less organic material, but it is rich in minerals because these get washed down with the rain. The lower layer (subsoil) is made of inorganic material, similar to the parent rock which originally formed the soil. |
| A result | B cause | C occur | |
| A dissolves | B pollutes | C removes | |
| A species | B growth | C roots | |
| A dying | B decaying | C growing | |
| A moisture | B air | C residues | |
| A capacity | B fertility | C balance | |
| A effects | B adds | C contains |
| Grammar |
Passive Voice
Ex. 5.11 Complete the following sentences. Put the verbs in brackets into the passive voice forms:
1) All living things (to make) of protein which contains nitrogen.
2) The essential nitrates (to remove) from the topsoil due to repeated cropping and overgrazing.
3) Thirty percent of the world’s land surface (to threaten) with desertification.
4) Plants which (to grow) in artificial fertilizers are often tasteless and have a low nutritional value.
5) Salinization (to cause) by perennial irrigation (that is, irrigation year after year without a break) in arid climates.
6) All soil contains some salt, which (to wash away) when it rains.
7) The quality of soil can (to improve) by adding fertilizers.
8) If we continue to dump animal and human waste into the sea instead of using it to fertilize the soil, our reserves (to lose) at the bottom of the oceans.
Ex. 5.12 Translate the following sentences into Russian. Pay attention to the tense and voice forms of the verbs:
1) The word “science” is derived from the Latin word “scire” that means “to know”, “to experience”.
2) The word “scientist” was introduced only in 1840.
3) A scientist develops theories from various observations, relationships and laws that have been accumulated.
4) The results of this experiment are being discussed and interpreted as a new stage in agrochemistry.
5) We understood that this theory on soil formation had been developed long ago.
6) This relationship is not viewed in the same way by all Russian soil scientists.
7) A new approach to the study of soil layers is being proposed at present.
8) This concept was held by the most participants of the XII International Scientific Congress on Soil Science Issues.
9) At present people are beginning to realize that natural soil resources must be wisely used.
Ex. 5.13 Translate the following sentences into English using the Passive Voice:
1) Данные вещества были протестированы в ходе эксперимента, проведенного в нашей лаборатории.
2) Доклад почвоведа из Англии был выслушан с большим вниманием.
3) Недавно эта модель была усовершенствована (модифицирована) и теперь успешно используется на практике.
4) На распространение тех или иных типов почв значительно влияют условия данной местности.
5) Ожидается, что наш научно-практический семинар по современным вопросам почвоведения посетят около 40 участников.
6) Лекции этого профессора кафедры агрохимии всегда сопровождаются оживленными обсуждениями.
7) Статью опубликовали после того, как было просмотрено и изучено большое количество материала по этой проблеме.
8) Система классификации почв основывается на концепции великого русского ученого Василия Докучаева.
9) За этим открытием нашей научной лаборатории вскоре последовало следующее.
Part 2
| Review |
Ex. 5.14 Read and review the text using the following phrases:
- The article under review is called …
-The main aim of the article is…
-The author deals with the problem of…
-Much attention is given to…
-The article can be recommended to a wide range of…
FERTILIZERS
The quality of soil can be improved by adding fertilizers. Organic fertilizers are made from animal and plant material such as compost (rotting plant matter) or manure (animal excreta) which return essential micronutrients such as nitrates, phosphates and potash to the soil. Artificial (inorganic) fertilizers are manufactured compounds that contain high concentrations of these micronutrients; they are much more powerful than natural organic fertilizers. But they cause environmental damage by a process called eutrophication. Excess nitrogen is washed out of the soil with the run-off after it rains. It passes into rivers and lakes, and encourages the growth of algae (seaweed) in the water and of wild plants on nearly land. Overgrowth of algae upsets the balance of nature in lakes and seas (see Chapter 8). Overcrowding on the banks causes the plants to rot and die. The air becomes contaminated with nitrous oxide which contributes to the greenhouse effect. Like nitrates, phosphates and potash are taken up by growing plants and returned to the soil in animal excreta. The phosphates and potash in artificial fertilizers must be extracted from rocks by mining, but these mineral resources will not last forever. If we continue to dump animal and human waste into the sea instead of using it to fertilize the soil, our entire reserves of these precious minerals will be lost at the bottom of the oceans. Artificial fertilizers add a few selected micronutrients, but because they cause rapid plant growth they deplete the soil of other nutrients. Plants grown in artificial fertilizers are often tasteless and have a low nutritional value. They may be contaminated with chemical residues from the fertilizer manufacturing process. For both environmental and health reasons, many consumers today prefer to by organic vegetables – that is, vegetables grown without any artificial fertilizers.
Organic vegetables are also grown without pesticides. These chemicals kill insects and other pests but they are poisonous to many other living things as well – including man. Pesticides are absorbed by the crops and washed into the rivers and the sea. They often become concentrated by the food chain. Some pesticides accumulate in the human body and are secreted in breast milk. About 20,000 people in the world, including many children, die each year from accidentally drinking or inhaling pesticides. Some pesticides may cause cancer, miscarriage or even birth defects. The effect of pesticides on increasing crop yields is often transient. Some pests become resistant to the chemicals. The pesticides might destroy the pest’s natural predators, so the farmer soon sees a paradoxical increase in the pest population. The so-called “miracle strains” of high-yield cereal crops are particularly vulnerable to pests. The farmer must use higher concentrations of pesticides each year to control the problem. Intensive farming of high-yield strains is usually associated with heavy use of both fertilizers and pesticides. Organic farming methods do not usually use these high-yield strains.