class 11-agriculture

class 11-agriculture - Agriculture, Biotechnology, and the...

Info iconThis preview shows pages 1–15. Sign up to view the full content.

View Full Document Right Arrow Icon
Agriculture, Biotechnology, and the Future of Food Feeding the Growing World
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Agriculture The practice of cultivating soil, producing crops and raising livestock for human use and consumption. Croplands Rangelands Forests Dependent on the soil
Background image of page 2
Soils A complex, plant-supporting system consisting of disintegrated rock, organic matter, air, water, nutrients and microorganisms Soil is a complex ecosystem.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Modern “Industrial” Agriculture The use of machines, fossil fuels, and chemical fertilizers in agriculture. Greatly increases the amount of food that can be produced per person. Intensive agricultural practices can threaten the soil that supports them, and cause other environmental damage, if they are not managed well.
Background image of page 4
Soil Degradation Overuse of soils can cause declines in productivity because of erosion, desertification and salinization. 5-7 million hectares of cropland are lost every year. Global grain production per person has begun to decline.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Soil Degradation Most soil degradation is caused by: Livestock overgrazing Deforestation Cropland agriculture
Background image of page 6
Soil Degradation Erosion loss of soil (wind and water) Desertification conversion of fertile land to desert Salinization buildup of salts in the upper layers of soil
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fertilizers Supply nutrients to crops Inorganic fertilizers = mined or synthetically manufactured mineral supplements Organic fertilizers = animal manure, crop residues, compost, etc. Both can cause problems if too much is applied. Over-Fertilization
Background image of page 8
Fertilizer runoff Overapplied fertilizer can run off into local water bodies, infiltrate into aquifers, and evaporate into air. Nitrates and phosphates can cause health problems.
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Pesticides Artificial chemicals have been developed to kill insects ( insecticides ), plants ( herbicides ), and fungi ( fungicides ). These poisons are collectively called pesticides .
Background image of page 10
Pests evolve resistance to pesticides Pesticides gradually become less effective, because pests evolve resistance to them. Some pests will survive because they happen to be genetically immune to the pesticide. Those few pests that survive pesticide applications will be the ones that reproduce and pass on their genes to the next generation.
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Pests evolve resistance to pesticides 1. Pests attack crop 2. Pesticide applied 3. All pests except a few with innate resistance are killed
Background image of page 12
Pests evolve resistance to pesticides 4. Survivors breed and produce pesticide-resistant population 5. Pesticide applied again 6. Has little effect. More-toxic chemicals must be developed.
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Solutions Many techniques have been developed to
Background image of page 14
Image of page 15
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/23/2011 for the course ENVSCI 101 taught by Professor Don'tremember during the Spring '11 term at Rutgers.

Page1 / 44

class 11-agriculture - Agriculture, Biotechnology, and the...

This preview shows document pages 1 - 15. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online