Tiếng anh chuyên ngành Thổ nhưỡng và Môi trường đất phần 10 pps

Tiếng anh chuyên ngành Thổ nhưỡngvà Môi trường đất
NXB Đại học quốc gia Hà Nội 2007.
Tr 92 – 100.


Tài liệu trong Thư viện điện tử ĐH Khoa học Tự nhiên có thể được sử dụng cho
mục đích học tập và nghiên cứu cá nhân. Nghiêm cấm mọi hình thức sao chép, in
ấn phục vụ các mục đích khác nếu không được sự chấp thuận của nhà xuất bản và
tác giả.


Mục lục

Unit 10 Soil texture, porosity, acidity 2
A. Reading 2
I. Comprehension questions 3
II. True-false questions 4
III. Increasing your vocabulary 4
B. Writing 5
C. Further practice 6
D. Translation 8
I. Translate into Vietnamese 8
II. Translate into English 8
E. Vocabulary 9

Unit 10. Soil texture, porosity, acidity

Nguyễn Thị Minh Nguyệt
Unit 10
Soil texture, porosity, acidity
A. Reading
• Warm-up activities
- Name the soils and their characteristics that you know.
- Which soil is best for growing most crops?

Soils vary in their content of clay (very fine particles), silt (fine particles), sand
(medium-size particles), and gravel (coarse to very coarse particles). The relative amounts
of the different sizes and types of mineral particles determine soil texture. Soils containing
a mixture of clay, sand silt and humus are called loams.
To get an idea of a soil's texture, take a small amount of topsoil, moisten it, and rub it
between your fingers and thumb. A gritty feel means that it contains a lot of sand. A sticky
feel means a high clay content, and you should be able to roll it into a clump. Silt-laden
soil feels smooth like flour. A loam topsoil, best suited for plant growth, has a texture
between these extremes-a crumbly, spongy feeling with many of its particles clumped
loosely together.
Soil texture helps determine soil porosity: a measure of the volume of pores or spaces
per volume of soil and average distances between those spaces. A porous soil (with many
pores) can hold water and air than a less porous soil. The average size of the spaces or
pores in a soil determines soil permeability: the rate at which water and air move from
upper to lower soil layers. Soil porosity is also influenced by soil structure: how soil
particles are organized and clumped together.
Loams are the best soils for growing most crops because they hold lots of water but
not too tightly for plant roots to absorb. Sandy soils are easy to work, but water flows
rapidly through them. They are useful for growing irrigated crops or those with low water

requirements, such as peanuts and strawberries.
The particles in clay soils are very small and easily compacted. When these soils get
wet, they form large, dense clumps, explaining why wet clay can be molded into bricks and
pottery. Clay soils are more porous and have a greater water-holding capacity than sandy
soils, but the pore spaces are so small that these soils have a low permeability. Because
little water can infiltrate to lower levels, the upper layers can easily become too
waterlogged for most crops.
Acidity and basicity of substances in water solution are commonly expressed in terms
of pH. Soils vary in acidity, and the pH of a soil influences uptake of soil nutrients by
plants. Plants vary in the pH ranges they can tolerate
(Taken from "Sustaining the Earth" by Tyler Miller, G.)
I. Comprehension questions
Answer the following questions
1. How do soils vary? How can we give a concept of soil's texture?


2. Which soils are loams ? Why are they the best for growing crops?


3. Why can we roll soil with a high clay content?


4. Why does a porous soil hold more water and air than a less porous soil?


5. What does soil permeability mean? What can determine it?


6. Why can people mould wet clay into bricks and pottery?

7. What are characteristics of the particles in clay soil?


8. Are sandy soils useful for growing peanuts and strawberries?


9. What does the soil structure have influence on?


10. Why are the upper layers easy to become waterlogged for crops?


II. True-false questions
Decide whether the following statements are true "T" or false "F". Correct the
false statements.
1. The relative amounts of the different sizes and types of mineral particles
determine loams.
2. People have to depend on clay, silt, gravel and sand content to group soil into
textual classes.
3. Loams are soils, which contain a mixture of clay, sand, silt, and humus.
4. It's difficult to get an idea of soil composition.
5. A less porous soil can hold less water than a porous soil.
6. There are not many pores in porous soil.
7. Sandy soil is good for growing peanuts and strawberries.
8. Bricks and pottery are made from wet clay.
9. Clay soils and sandy soils have the same water-holding capacity.
10. The pore spaces of clay soils are very small.
III. Increasing your vocabulary
Complete the following statements with the appreciate words given below:

sand water and air mineral particles
gravel wet clay sandy soil
loams clay content soil texture
11. Soils containing a mixture of a clay, sand silt and humus are called (1)
12. Bricks and pottery are made from (2)
13. A porous soil (with many pores) can hold (3) than a less porous soil.
14. (4) are easy to work, but water flows rapidly through them.
15. A gritty feel means that it contains a lot of (5)
16. A sticky feel means a high (6)
17. The relative amounts of the different size and of (7) determine
(8)
18. Soils vary in their content of clay, silt, sand and (9)
B. Writing
Sentence-transforming
Finish each of the following sentences in such a way that it means the same as the
sentence printed before it.
1. Soil containing a mixture of clay, sand, silt and humus are called loams.
Loams are soils which


2. A porous soil can hold more water and air than a less porous soil.
A less porous soil


3. Loams are the best soils for growing most crops because they hold lots of water but
not too tightly for plant roots to absorb.
As


4. It is useful for growing irrigated crops in sandy soils.

Sandy soils


5. People can mold wet clay into bricks and pottery.
Brick and pottery


6. Clay soils have a greater water-holding capacity than sandy soils.
Sandy soils


C. Further practice
Exercise 1: Expression of degree
Look at the following pairs of sentences. Notice that the first half of each sentence
describes a state and the second half expresses a consequence.
Example:
The soil was dry so the seed could not germinate.
The soil was heavy and clayey and , as a result, it was unsuitable for
root crops
We can express these sentences in another way using the expression of degree too:
Example:
The soil was too dry for the seed to germinate.
The soil was too heavy and clayey to be suitable for root crops.
Rewrite the following sentences using too as in example (c) and (d) above and make
any other changes that are necessary.
7. The soil particles are fine so the water cannot percolate easily through the soil.


8. Because the soil was compact, it was not suitable for root crops.

9. Soil aeration was inadequate and consequently the plant could not receive a proper
supply of oxygen.


10. As a result of the land being waterlogged, it was not possible to produce a healthy
crop.


11. The soil profile was so shallow that it could not give the roots sufficient anchorage.


12. As the root system was poorly developed, the plant could not produce a good top
growth.


13. It was dark as a result photosynthesis could not take place.


14. The current was so swift that the silt would not be deposited.


Now look at the sentences you have written and rewrite them using
not + adjective + enough, using the adjective given for each sentence .
Example:
The soil was too dry for the seed to germinate. (wet)
= The soil was not wet enough for the seed to germinate.
The soil was too heavy and clayey to be suitable for root crops. (light
and sandy)
= The soil was not light and sandy enough to be suitable for root crops.

1. The soil particles are fine so the water cannot percolate easily through the soil
(coarse).


2. Because the soil was compact, it was not suitable for root crops.
(loose)


3. Soil aeration was inadequate and consequently the plant could not receive a proper
supply of oxygen.
(adaquate)


4. As a result of the land being waterlogged, it was not possible to produce a healthy
crop.
(well-drained)


5. The soil profile was so shallow that it could not give the roots sufficient anchorage.
(deep)





6. As the root system was poorly developed, the plant could not produce a good top
growth.
(well-developed)

7. It was dark as a result photosynthesis could not take place.
(bright)


8. The current was so swift that the silt would not be deposited.
(slow)


D. Translation
I. Translate into Vietnamese
The soil is always an important component in the system comprising the lithosphere,
the atmosphere and the biosphere. Soil particles reflect the varying nature of the
interactions with this system. Soil is very essential for many human activities, and we can
only successfully and sustainably undertake these activities if we understand how soil has
been developed and how it is affected by changes in the system, particularly those in the
biosphere caused by our manipulation of vegetation and soil.
(Taken from "Environmental Sciences" by Wilson, R.)
II. Translate into English
1. ánh sáng mặt trời cung cấp năng lượng cho quá trình chuyển nước từ đất và cacbon
điôxít từ không khí thành đường và hyđrát cacbon.


2. Việc canh tác quá nhiều làm phá hủy cấu trúc của đất.


3. Nếu đất quá lạnh thì sự nảy mầm của cây cối không thể xảy ra.


4. Thành phần cơ giới là đặc tính quan trọng của đất bởi vì ở một phạm vi nào đó nó sẽ
quyết định tỷ lệ hút nước, sự tích trữ nước ở trong đất, tính thấm khí và nó sẽ ảnh

hưởng đến độ phì nhiêu của đất. Ví dụ, đất cát thô rất dễ canh tác, có tính thấm khí tốt
cho sự phát triển của rễ và dễ làm ướt, nhưng loại đất này cũng khô rất nhanh và dễ bị
mất các chất dinh dưỡng cho cây trồng. Còn các loại đất sét lại rất khó làm ướt, khó
canh tác và cũng khó tháo rút nước.






E. Vocabulary
1. absorb (v) : hấp thụ, ngấm
2. brick (n) : gạch
3. clay (n) : đất sét
4. clump (v) : tạo thành lùm, thành đống
5. coarse (adj) : thô, không mịn
6. compact (adj) : nén, rắn chắc
7. content (n) : hàm lượng
8. dense (adj) : dày đặc, chặt
9. grit (n) : hạt cát, hạt sỏi
10. infiltrate (v) : xâm nhập
11. irrigate (v) : tưới nước
12. loam (n) : đất giàu mùn, đất thịt
13. moisten (v) : làm ẩm
14. mold (v) : đúc theo khuôn
15. permeable (adj) : dễ them
16. porous (adj) : lỗ rỗng, tính rỗng
17. pottery (n) : đồ gốm
18. roll (v) : cuộn tròn, vo viên
19. rub (v) : chà xát

20. sticky (adj) : dẻo, dính
21. spongy (adj) : mềm, xốp, đàn hồi
22. tolerate (v) : chịu đựng
23. volume (n) : khối lượng
24. waterlogged (adj) : ngập úng