Page 69 - Introduction to Agriculture by: Aqleem Abbas
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Introduction to Agriculture Notes prepared by: Aqleem Abbas
Humus can be added to the soil at any time of year. It can be worked into the soil, where its benefits take effect most rapidly, or it
can be left on the soil surface. Humus can be used year after year, and there is never danger of adding too much, since this
remarkable substance only enhances soil and encourages plants to thrive.
Cities compost on a large scale to reduce yard waste so that it does not take up space in landfills. Industries compost hazardous
materials because the activities of the microorganisms help break down toxic substances into less-harmful or harmless materials.
Many municipalities provide information on composting as part of their programs to reduce the amount of solid waste entering
their landfills. County or regional offices of the state Cooperative Extension Service also have information on composting.
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Organic Farming
Introduction
Organic Farming, system of agriculture that excludes the use of synthetic pesticides, growth hormones, antibiotics, genetically
modified seeds and animal breeds, and irradiation. Organic farmers instead rely on ecosystem management, including the use of
pesticides and fertilizers derived from plants, animal wastes, and minerals. They incorporate biological methods, such as the use
of one organism to suppress another, to help control pests. The methods used in organic farming seek to increase soil fertility,
balance insect populations, and reduce air, soil, and water pollution.
In the United States, organic farming is a rapidly growing sector of agriculture. In 2006 organic food sales reached $16.7 billion,
up from $7 billion in 2001. Exports of organic food products are also growing, particularly to Japan and Europe.
Organic farming techniques
Organic farming combines a variety of methods to maintain the health of soil, prevent soil erosion, and control pests with
minimal or no use of synthetic pesticides. Conventional farmers also use some of these methods, but to a lesser degree.
Soil preservation in organic farming
Fertilizers are used to provide the minerals lacking in some soils, and to replace the minerals removed from the soil by crops as
they grow. Many conventional farmers rely on concentrated chemical fertilizers that are rapidly absorbed by plants. These
fertilizers produce quick growth but may kill important soil organisms, such as earthworms and beneficial bacteria. Organic
farmers use manure, compost (a mixture of decaying organic matter that is rich in beneficial soil microorganisms), and other
natural materials to nourish soil organisms, which in turn make minerals available to plants.
Organic farmers are more likely than conventional farmers to rotate crops, a technique that replenishes soil nutrients without the
use of synthetic fertilizers. In crop rotation, a field is used for one to several years to grow one type of crop, such as corn or
wheat, followed by a season in which a legume such as alfalfa or soybean is planted. Legume roots harbor beneficial bacteria that