Soil, Pollution, Land Use, and Farming Systems – Lecture Notes Flashcards

This set covers key concepts from the notes on soil depth effects, land use planning, pollution and soil degradation, contour farming, and various farming systems (intensive, semi-intensive, extensive, and precision/vertical farming).

How does soil depth influence water availability for plants?

Deeper soils can store and transmit more water, reducing irrigation needs; shallower soils may lead to waterlogging and drought stress.

How does soil depth affect root growth in crops?

Deeper soils allow roots to grow deeper and access water reserves; shallow-rooted crops may struggle in shallow soils.

What is the effect of soil depth on nutrient availability?

Depth influences nutrient distribution; nutrients may be concentrated in the topsoil or distributed through the profile, affecting uptake.

Why is soil aeration influenced by soil depth?

Deeper soils generally have better aeration; shallow soils may have reduced oxygen, hindering root development.

How does soil depth relate to soil temperature stability?

Deeper soils tend to have more stable temperatures; shallow soils experience greater fluctuations.

What is the relationship between soil depth and erosion risk?

Shallow soils are more susceptible to erosion and soil degradation than deeper soils.

Which crops illustrate the impact of soil depth on crop selection?

Deep soils suit crops like carrots and parsnips; shallow soils suit crops like spinach and lettuce.

What does it mean that soil properties are transferable but sustainability is not?

Soil properties can be transferred between uses, but sustainability is context-specific to a particular use.

Are good agricultural lands always suitable for engineering purposes?

No. Land good for one crop may be unsuitable for another use or for engineering purposes.

Why must soil properties be interpreted as a combination of factors?

Soil behavior depends on multiple interacting factors, including texture, depth, clay mineralogy, and layer thickness.

Why might shallow soils be physically active and risky?

Shallow soils can be prone to cracking and instability under loading, increasing structural risk.

How does technology affect soil suitability and management?

Technology (e.g., ripping) can improve the use of challenging soils (e.g., compacted sandy soils) and enable higher productivity.

What is contour farming?

A practice where farming operations follow contour lines on slopes to reduce runoff and erosion.

What are contour lines in agriculture?

Lines that run across a slope at a constant elevation, staying level rather than ascending or descending.

Why are contour lines used in farming?

To combat surface erosion, improve water infiltration and drainage, and stabilize soils.

On which slopes is contour farming most effective?

Generally on slopes between about 2% and 10%.

What is the maximum driving (row) gradient for contour farming?

The gradient should not exceed half of the uphill slope percentage or 2%, whichever is less.

What are stable outlets in contour farming?

Grass waterways or underground outlets that safely convey concentrated water flow.

What is the role of cover crops and mulching in contour farming?

They reduce overland flow, erosion, and nutrient leaching, and improve moisture retention.

What are some disadvantages of contour farming?

It can be expensive, require capital for contour walls, and limit heavy machinery movement to contour strips.

What is land use planning in farming?

Regulating land use to promote desirable production and environmental outcomes and efficient resource use.

What is soil pollution?

Introduction of harmful substances into soil, such as heavy metals, pesticides, or industrial waste.

What are soil pollutants?

Substances that harm soil health, including xenobiotics, chemicals, and waste.

What constitutes veld pollution?

Litter, invasive species, chemical drift, veld fires, and alien vegetation.

What are related environmental terms in the notes?

Ecotoxicology, soil remediation, waste management, sustainable practices.

What are the main types of soil degradation?

Erosion, compaction, salinization, acidification, and nutrient depletion.

What is desertification?

The process of land degradation in drylands due to climate change, overgrazing, or unsustainable practices.

What is soil conservation?

Practices to protect soil health and fertility, reducing erosion, nutrient loss, pollution, and degradation.

What management practices help reduce soil erosion?

Increase organic matter, protect with crop residues, minimize tillage, use legumes and cover crops, proper manure storage, and integrated pest management.

What is contour cultivation?

Planting and cultivation along contour lines to reduce runoff and erosion on slopes.

What is terracing?

Creating stepped levels (terraces) on slopes to reduce runoff and erosion.

What is farm planning in terms of farming systems?

Choosing among subsistence, commercial, monoculture, polyculture, organic, and biodiversity-based approaches and understanding their trade-offs.

What are characteristics of intensive farming systems?

High production, high input use, controlled environments, and heavy machinery use; aims for high yields.

What is precision farming?

Use of technology and data to apply inputs precisely where and when they are needed.

What are examples of precision farming technologies in crops and livestock?

Sensor networks, variable-rate irrigation, data analytics, automated feeding, and monitoring systems.

What is regenerative agriculture?

A farming approach focused on rebuilding soil health, biodiversity, and ecosystem services, often via grazing management, cover crops, and reduced disturbance.

What are semi-intensive farming systems?

Balanced systems with more space and some open areas, combining elements of intensive and extensive practices.

What are extensive farming systems?

Low input, large land areas, grassland-based or free-range, prioritizing welfare and sustainability with typically lower productivity.