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Nutrient
and Sediment Research
Background on Nutrient and
Sediment Research
Sections in this Report
:
| Background
on Nutrients | Causes
for Concern | Eutrophication
| Excessive Nitrates
| The
Role of Sediments | Local
Responsibility | Nutrient
and Sediment Research | Recommended
Safe Levels | Current
Research 1992-93 | Miami
Site | Twin
Watershed Site | Twin
Watershed Results | Summer
Storms | Spring
Runoff | Three
Rain Events | 1993
Sediment / Nutrient Loadings | Research
Conclusions | Future
Work | A
Final Word | Additional
Information
Nutrients
and Their Sources
Nutrients and Agriculture
Nutrients are a variety of chemical elements
which provide essential nourishment to growing plants and animals.
In the natural world, nutrients are released through soil weathering and
plant usage; they play an essential role in all of earth's biological processes.
In agricultural regions the availability
of an adequate supply of nutrients is also essential for the successful
production of crops. The two most common nutrients applied by farmers
are nitrogen (N) and phosphorus (P).
These nutrients occur in a variety of forms,
and both N and P are affected by chemical and biological processes which
can change their forms, permitting movement between water, soil, living
organisms, and the atmosphere.
Early plant growth under
alternative management practices. Left side is conventional tillage.
The right side is direct seeding.
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Since the beginning of agricultural development,
humans have worked to maximize food production and minimize energy and
costs used in the production process.
| Increased crop production
may be achieved by: |
|
| ...1. |
Increasing the amount
of land used for agriculture; |
| ...2. |
Improving agronomic
practices, such as improved crop varieties, weed control, and the application
of nutrients; |
| ...3. |
Enhancing production
via irrigation from secure water sources. |
Over the centuries, agronomic practices have
developed to a high level of sophistication. At one point, animal
manure was the most widely used additional nutrient applied. Manure
was viewed as a high nutrient crop input which also helped increase the
organic matter content of soils.
Since the 1950's, in the era of high yield,
science based agriculture, the application of engineered forms of nitrogen
and phosphorus have assisted in dramatically increasing agricultural production
levels. Improved packaging, distribution, and application have assisted
in making plant nutrients more readily available to growing crops.
Higher yields have subsequently resulted in stable supplies of relatively
low cost food products.
High levels of production.
|
 |
Harvest for a hungry world.
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In some areas, the intensification of agriculture,
and the use of conventional farming practices have caused soil nutrient
levels to decline. In recent years however, a wide range of conservation
practices have been incorporated to enhance the availability of nutrients
for agricultural crops (i.e. reduced nutrient loss).
Using stubble from the
previous year's crop helps protect growing plants and soil from erosion
by wind and water. This increases soil moisture, infiltration, and retention,
while assisting to maintain stable nutrient levels.
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Currently, there is a renewed appreciation
among farmers for the nutrient value of cattle and hog manure, and many
new approaches are being explored in search of the optimum methods of incorporating
this valuable resource into the soil.
High organic matter manure
broadcasted on field surface.
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Some liquid manure is broadcasted
on the field surface.
 |
Some liquid manure is injected
below field surface.
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Livestock manure is generally applied in one
of several methods, depending on the manure consistency. In the case of
bulky, high organic and liquid manure they can be surface applied and tillage
incorporated. With liquid manure , there is an option for direct injection
below the soil surface, hence minimizing/reducing nutrient loss and odour
concerns.
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