Ch. 10 Notes_ Farming_ Conventional and Sustainable Practices

Soil

A complex ecosystem that is a renewable resource composed of minerals, organic material, water, air, and living organisms.

Soil Horizons

Horizontal layers of soil that together make up the soil profile.

Organic Agriculture

Farming without synthetic fertilizers or pesticides, emphasizing ecological balance and sustainability.

Desertification

The process by which productive land becomes desert due to various factors like climate change and overuse.

Erosion

The process by which soil is removed from an area, typically accelerated by water and wind.

Mollisols

A soil type prevalent in the US, characterized by a thick, organic-rich A-Horizon, ideal for agriculture.

Alfisols

A soil type that develops under deciduous forests; it has a thinner A-Horizon and less organic material than mollisols.

Pesticide Treadmill

A situation where pesticide-resistant pests demand increasingly potent chemicals, leading to a cycle of increased pesticide use.

Integrated Pest Management (IPM)

A strategy that uses a combination of techniques to manage pest populations while minimizing pesticide use.

Cover Crops

Plants grown to protect and enrich soil between regular crop seasons, preventing erosion and retaining nutrients.

Salinization

The accumulation of salt in soil, often due to excessive irrigation, which can be harmful to plants.

Biocides

Chemicals used to kill a wide variety of living organisms, including pesticides.

Environmental Impact of Agriculture

Agriculture has dramatically altered vegetation patterns, soils, and water resources worldwide.

Soil Accumulation Rate

Top soil accumulates at a very slow rate of approximately 1mm per year under optimal conditions.

Components of Soil

The six components of soil include sand and gravel, silts and clays, dead organic material, soil fauna and flora, water, and air.

Soil Texture

Soil texture refers to the amounts of sand, silt, and clay present in the soil, which is crucial for determining its characteristics.

Loam Soils

Loam soils are considered ideal for agriculture as they balance sand, silt, and clay, allowing for good water and nutrient retention.

Mycorrhizal Symbiosis

An association between plant roots and certain fungi that helps enhance plant growth by providing water and nutrients.

Soil Horizons

Soils are stratified into horizontal layers called horizons, which together make up the soil profile.

O Horizon

The Organic layer in the soil profile where leaf litter and soil organisms are abundant.

A Horizon

The Surface soil layer where mineral particles are mixed with organic materials.

E Horizon

The washed-out layer of soil that is often depleted of soluble nutrients.

B Horizon

The subsoil layer that has a denser texture due to clays.

C Horizon

This layer consists of weathered rock fragments with minimal organic materials.

Mollisols

A rich, organic soil type found in the U.S., characterized by a thick A-horizon developed from deep roots.

Alfisols

A soil type developed under deciduous forests, thinner in A-horizon and less organic material than mollisols.

Desertification

The process of converting productive land into desert, threatening ⅓ of the earth’s surface.

Soil Erosion Types

Sheet erosion, rill erosion, gully erosion, and stream bank erosion are different ways soil is removed.

Waterlogging

A condition where excessive watering causes plant roots to die from lack of oxygen.

Salinization

The accumulation of mineral salts in soil due to irrigation with salt-laden water.

Contour Plowing

A farming technique involving plowing across slopes to slow water flow and minimize erosion.

Crop Rotation

The practice of alternating the types of crops grown in a specific field to maintain soil fertility and reduce pests.

Integrated Pest Management (IPM)

An ecologically based strategy that reduces pesticide use while maintaining crop yields.

Biological Pest Control

Using organisms like insects or fungi as a natural method to compete with pests consuming crops.

Persistent Organic Pollutants (POPs)

Chlorinated hydrocarbons like DDT that are stable, bioaccumulate, and have harmful environmental effects.

Organic Agriculture

Farming that avoids synthetic fertilizers, pesticides, and genetically modified organisms to promote sustainability.

Locavores

Individuals who choose to eat locally produced food to reduce environmental impact.