Transcript Agriculture Notes III

Agriculture Notes III
Fertilizers
• Fertilizers – substances added to soil to
provide nutrients for plant growth
• Plants require large quantities of three
nutrients: Nitrogen, Phosphorous, and
Potassium (N-P-K)
Fertilizers
• Nitrogen – necessary for proper growth of
plant leaves and stems, phosphorous –
necessary for good root growth and flower
and seed formation, potassium – necessary
for proper growth and resistance to disease
• Plants also require several other nutrients (in
lesser amounts)
Organic vs. Synthetic Fertilizers
• Synthetic fertilizers – human-made products.
Involves chemically changing nutrients so they
are available for plants
• Organic fertilizers – natural fertilizers made
from dead organisms or their waste products.
Their production involves physical changes
and any chemical changes that occur must be
natural.
Advantages of Synthetic Fertilizers
• Cheaper to purchase than organic
• Nutrients are concentrated, only small
amounts needed
• Concentration of nutrients need to meet
industry standards and can be easily
determined by reading the label
• Nutrients are quickly available for plant
absorption
Disadvantages of Synthetic Fertilizers
• If too much is used or it is placed to close to
plant, the concentrated chemicals can harm
plant
• People often over apply
• Easily leached from the area of the plant roots
• Do not increase humus content of soil
• Require a significant amount of energy for
their production
Advantages of Organic Fertilizers
• Most are not concentrated and will not harm
plants
• Available for longer period of time and are less
likely to be lost from the soil
• Many organic fertilizers add humus to the soil
Disadvantages of Organic Fertilizers
• More expensive to purchase than synthetic
fertilizers
• Large amounts are required to provide proper
nutrients
• The nutrient levels will vary with the
materials used
• Organic materials must be composted before
their nutrients are available to the plants
Genetically Modified Organisms
• Created by taking a gene(s) from on species
and putting it (them) into a different species
• Sometimes GMOs are referred to as
transgenic organisms
• GMOs have been produced to make crops
healthier, hardier, and to protect them from
pests
http://www.youtube.com/watch?v=6NsI0ba9dNg
http://www.youtube.com/watch?v=1_pYa3JlIQ4
Pros of GMOs
• Can make crops healthier, hardier, and/or
disease resistant
• Can increase crop yields
• Can reduce need for pesticides
• Can increase food quality and taste
Cons of GMOs
• Not enough testing (especially long-term testing)
to determine their effects
• Allergic reactions – the development GMOs often
introduces new proteins into organisms that
previously lacked those proteins. This has the
potential to cause allergies.
• Some GMOs have an antibiotic component to
them. Consumption of these GMOs can decrease
the effectiveness of antibiotics.
• Modified proteins may escape into the wild
possibly altering other organisms.
Organic food
• The USDA has established national standards
that must be met in order for a foods to be
labeled “Certified Organic”
http://www.ams.usda.gov
• The USDA National Organic Program (NOP) defines organic
as follows:
Organic food is produced by farmers who emphasize the
use of renewable resources and the conservation of soil and
water to enhance environmental quality for future
generations. Organic meat, poultry, eggs, and dairy
products come from animals that are given no antibiotics or
growth hormones. Organic food is produced without using
most conventional pesticides; fertilizers made with synthetic
ingredients or sewage sludge; bioengineering; or ionizing
radiation. Before a product can be labeled "organic," a
Government-approved certifier inspects the farm where the
food is grown to make sure the farmer is following all the
rules necessary to meet USDA organic standards.
Companies that handle or process organic food before it
gets to your local supermarket or restaurant must be
certified, too.
http://www.organic.org/home/faq