I. Agriculture & Soil

A. Basic process of farming:

1. Plowing

2. Fertilization

3. Irrigation

4. Pest Control

B. Fertile soil – Soil that supports the growth of healthy plants

1. Topsoil – Surface layer of soil

a. Rich in organic matter needed for plant growth

2. Soil forms through a process called physical and chemical weathering

a. Physical weathering – Wind and water

b. Chemical weathering – Minerals in rock react with substances in water

Pg. 381, Figure 8 – Know it

II. Soil Erosion, and Conservation

A. Erosion – Wearing away of rock and soil by wind and water

B . Land degradation – Land being damaged by either human activity or natural process

1. Results in land that can no longer sustain an ecosystem

2. Desertification – Arid or semiarid areas become more desert like b/c of human activity

C. Methods of soil conservation:

1. Contour plowing – Plowing across the slope of a hill, not up and down the slope

2. No-till farming – Crops harvested w/out turning over the soil

a. Later crops are planted among the remains of the previous crop

D. Traditional fertilizers have been organic matter

1. Modern fertilizers are made of inorganic chemicals which contain nitrogen, phosphorus, and potassium

E. Compost – Fertilizer made of mostly organic material

III. Pest Control

A. Worldwide, pests control about 33% of all potential food crops

1. Pest – Any organism that occurs where it is not wanted OR that occurs in numbers large enough to cause economic damage

B. Pesticides – Chemicals used to kill insects, weeds, & other crops

C. Pesticides:

1. Organisms can develop resistance

2. Can present health concerns

3. Can be persistent – linger in the environment

D. Biological pest control – Use of living organisms to control pests

1. Pathogens can cause disease in pests

E. Genetic Engineering – Modifying an organisms genes to be resistant to certain pests

1. Allows scientists to produce plants that are resistant to disease and pests