ESS Topic 5

Question 1

What is soil composed of, and what are its key characteristics?

Answer 1

Soil is a mixture of minerals, organic matter, air, and water, serving as a medium for plant growth, a water storage and purification system, and a habitat for many species.

Question 2

List the primary functions of soil in an ecosystem.

Answer 2

Medium for plant growth, major water storage and purification system, habitat for a quarter of all living species, and modifies through respiration of soil organisms and plant roots.

Question 3

What factors influence the characteristics of soil?

Answer 3

Climate, organisms, relief, parent material, and time.

Question 4

Identify and describe the biotic components in soil.

Answer 4

Micro-organisms (bacteria, algae, fungi) and macro-organisms (earthworms, insects, mites, millipedes).

Question 5

What are the inputs to the soil system?

Answer 5

Inputs include minerals, organic matter, gases, and water.

Question 6

Describe the outputs from the soil system.

Answer 6

Outputs involve erosion, nutrient uptake by plants, and leaching.

Question 7

Explain the different layers of the soil profile.

Answer 7

O horizon (organic), A horizon (topsoil with high organic content), B horizon (subsoil with accumulated minerals), C horizon (weathered parent material).

Question 8

What are the causes of soil degradation?

Answer 8

Deforestation, intensive grazing, urbanization, certain agricultural practices like irrigation and monoculture.

Question 9

List different types of soil degradation.

Answer 9

Erosion, soil becoming unusable due to pollutants, and leaching of nutrients.

Question 10

What strategies can be used for soil conservation?

Answer 10

Soil conditioners, wind reduction techniques, cultivation techniques (terracing, contour ploughing), avoiding use of marginal lands.

Question 11

Compare the impact of commercial and subsistence farming on soil fertility.

Answer 11

Commercial industrialized farming tends to reduce soil fertility more than small-scale subsistence farming.

Question 12

Describe the characteristics of clay soils.

Answer 12

Limited mineral content, poor drainage, high water retention.

Question 12

Why is soil considered a dynamic ecosystem?

Answer 12

It has inputs, outputs, storages, and flows, and influences primary productivity with diverse microorganisms, especially in the rhizosphere.

Question 13

Describe the characteristics of sand soils.

Answer 13

Moderate mineral content, high drainage, low water retention.

Question 14

Describe the characteristics of loam soils.

Answer 14

High mineral content, balanced drainage and water retention, supports the highest biota.

Question 15

Compare inputs and outputs in subsistence vs. commercial farming.

Answer 15

Subsistence farming generally involves fewer inputs and outputs focused on self-sufficiency, while commercial farming involves higher inputs (chemicals, machinery) and outputs for profit

Question 16

Provide a case study of soil degradation in a specific region or country.

Answer 16

In the Amazon Rainforest, soil degradation is primarily caused by deforestation for agriculture and cattle ranching. The removal of trees disrupts the nutrient cycle, leading to nutrient depletion in the soil. The exposed soil is then subject to erosion, further reducing its fertility. This degradation impacts the biodiversity of the region and contributes to climate change due to the loss of carbon-sequestering forests.

Question 17

Analyze the causes and effects of soil erosion in agricultural systems.

Answer 17

Soil erosion in agricultural systems is primarily caused by deforestation, overgrazing, improper ploughing methods, and the absence of cover crops. These activities expose soil to wind and water erosion. The effects of soil erosion include loss of topsoil, reduced soil fertility, and increased sedimentation in water bodies, which can lead to decreased agricultural productivity and ecological imbalances in nearby aquatic environments. Soil erosion also contributes to the release of carbon stored in the soil, impacting global carbon cycles.

Question 18

Evaluate different soil conservation methods and their effectiveness.

Answer 18

Soil conservation methods such as terracing, crop rotation, cover cropping, and the use of organic fertilizers are effective in different ways. Terracing on slopes prevents runoff and erosion, preserving soil fertility. Crop rotation and cover cropping maintain nutrient levels and soil structure, preventing erosion and enhancing soil biodiversity. Organic fertilizers improve soil structure and nutrient content without the harmful side effects of chemical fertilizers. The effectiveness of each method varies based on local environmental conditions and agricultural practices. For example, terracing is highly effective in mountainous regions, while crop rotation is more applicable in large-scale arable farming.