Professional Development Program






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Unit 1: Basic Ecological Concepts and Principles Related to Agricultural Systems

Click on the images below to learn more about boundaries and borders in several agricultural ecosystems.

This image shows a dairy farm in upstate New York nestled in a small valley. Moving from foreground to background, look for the following zones:

  • grassy slope with trees and shrubs

  • pasture with another area of trees and shrubs

  • a swath of deciduous trees in fall color (leading to the farm and silo)

  • a field of corn in tassel

  • a road (indicated by telephone poles)

  • and finally the hill, densely wooded

Think about the boundaries between each of these zones and what might be moving from one to the other: leaves, insects, water, animals, or nitrogen and other chemicals. What else? Consider also the entire farm ecosystem as a whole: What is moving across that whole-farm boundary in terms of inputs and outputs?


This image shows the sharp and distinct agricultural boundaries associated with large-scale, highly mechanized agriculture. Each circle can be viewed as a separate field ecosystem (defined by the radius of the center-pivot system). Nonetheless, there are no barriers separating the fields and living organisms can move into adjacent fields, affecting pest management. Soil can also move across fields through the action of wind and water. Note in the image that the Columbia River is adjacent to the farm (at the top of the photo) and that there is a water course that drains directly into the Columbia River. The river forms a natural boundary for this farm and its proximity clearly shows how farm and ranch management affects the larger ecosystem. An important goal for farmers managing a system like this is to make  irrigation as efficient as possible, providing sufficient quantities for crop growth and production, while reducing runoff.


Hedgerows form another kind of boundary in agroecosystems. Many farmers and ranchers across the country plant and manage hedgerows or vegetative buffers along the edges of their fields. This image shows this kind of boundary management along Bear Creek in Story County, Iowa. Research is showing that these plantings can:

  • provide habitat for pollinators and other beneficial organisms that can aid pest control

  • serve as a trap crop for harmful pests

  • reduce runoff and increase water infiltration in soil

  • absorb, dissolve and trap contaminants

  • reduce soil compaction from equipment

  • provide nesting areas, food and cover for wildlife, especially birds

  • protect crops from wind damage

Hedgerows have to be managed and maintained properly in order to thrive and provide long-term benefits. You can learn more about hedgerows and farmscaping in Unit 2.

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