Session 1: Selection of Site for Cultivation of Ornamental Crops
Unit 4: Field Preparation and Cultural Operations
Textual Question-Answers
Check Your Progress
Fill in the Blanks
1. The colour of the soil depends on ——————— and ———— —
Ans: mineral content and organic matter
2. Transformation of rocks into agricultural land is called ——————
Ans: weathering
3. The soil can be classified as per the size of soil particles. This istermed as ———————
Ans: soil texture
4. The inter-particle spaces of soil are known as ———————
Ans: pore spaces
5. The capacity of the soil to resist sudden change in pH is called ——————— capacity of soil.
Ans: buffering
6. A soil type ideal for horticultural crop is ———————
Ans: loamy soil
7. Soil acidity can be corrected by the application of ——————— to the soil.
Ans: lime
8. Soil science is also known as ———————
Ans: pedology
Multiple Choice Questions
1. Maximum plant nutrients are available, when the pH rangesfrom ——————
(a) 8 to 8.5
(b) 6.5 to 7.00
(c) 7 to 7.5
(d) 6 to 6.4
Ans: (b) 6.5 to 7.00
2. —————— acidic soils, predominates population of microbesin
(a) Fungi
(b) Algae
(c) Bacteria
(d) Protozoa
Ans: (a) Fungi
3. The pH of black soil varies from ———————
(a) 7.2 to 8.5
(b) 4.2 to 6
(c) 6 to 6.5
(d) 6.2 to 6.8
Ans: (a) 7.2 to 8.5
4. The ability of soil to change the shape or moulding when it is wetis due to ———————
(a) soil structure
(b) soil texture
(c) buffering
(d) soil consistency
Ans: (d) soil consistency
5. Desert soils are sandy soils found in ———————
(a) low rainfall
(b) high rainfall
(c) moderate rainfall
(d) None of the above
Ans: (a) low rainfall
6. Measuring the quantity of cations that can be absorbed and heldby the soil is known as ———————
(a) pH
(b) temperature
(c) buffering
(d) cation exchange capacity
Ans: (d) cation exchange capacity
Subjective Questions
1. Describe the physical properties of soil.
Ans: The physical properties of soil include colour, texture, structure, porosity, permeability, consistency and water-holding capacity. Theseproperties influence soil aeration, moisture retention and root penetration.
2. Describe acidic soil.
Ans: Acidic soil is soil with pH below 7. It is common in high rainfall areas where bases are leached out. Such soils favour fungal population andmay reduce the availability of some plant nutrients.
3. What is saline soil? Give the causes of soil salinity.
Ans: Saline soil contains excessive soluble salts which affect plant growth. Causes include poor drainage, high evaporation, use of saline irrigation waterand accumulation of salts in arid and semi-arid regions.
4. Write the characteristics of the following soils of India:
(a) Alluvial soil
Ans: Alluvial soil is fertile, rich in potash and lime, and suitable for awide range of crops. It is found in river plains.
(b) Laterite soil
Ans: Laterite soil is acidic, rich in iron and aluminium, low in fertility andfound in high rainfall areas.
(c) Black soil
Ans: Black soil is clayey, rich in calcium and magnesium, has high waterholding capacity and is suitable for cotton cultivation.
(d) Red soils
Ans: Red soils are light textured, rich in iron oxide, poor in nitrogen andorganic matter and are found in dry regions.
Match the Columns
A
1. Horizontally arranged particles
2. High organic matter
3. Neutral pH
4. Alkaline soil
B
(a) 7 pH
(b) 8.5–10 pH
(c) Platy structure
(d) More CEC
Ans:
1 – (c) Platy structure
2 – (d) More CEC
3 – (a) 7 pH
4 – (b) 8.5–10 pH
