Over 90 percent of the drinking water consumed in Idaho is supplied by
groundwater. This resource is vital to homeowners and industry.
Recent surveys in Idaho have found trace amounts of chemicals--nitrate--and, in
some cases, pesticides in some of Idaho's drinking water. Nitrates and pesticides
can get into groundwater through agricultural, industrial, and homeowner uses
as well as spills and improper disposal. Contaminated water is difficult and
expensive to manage once it becomes dispersed underground.
Your Garden Ecosystem
Think of your garden as a self-perpetuating ecosystem, a grouping of plants,
animals, and other organisms interacting with each other and their
Look at your complex garden ecosystem. You will see ornamental plants, fruit
trees, vegetables, and weeds, but there is much more. Your garden is also visited
by animals, insects, and birds. Your soil is teeming with worms, insects, fungi,
and microorganisms such as bacteria.
All ecosystems have three basic interacting categories of organisms:
Producers are generally green plants. Consumers include insects
and animals. Decomposers include insects and microorganisms.
Producers. Green plants convert sunlight, carbon dioxide, and water into
energy for plant growth through a process called photosynthesis. All energy
needed to make your garden ecosystem function smoothly is created by the
Consumers. These are the organisms that feed on live plant or animal
material. Some consumers are animals or insects that eat the green plants in your
garden, and others are animals that eat other animals in your garden.
Decomposers. Dead plant and animal material are used by decomposer
organisms as an energy source. Some of these decomposers we can see with the
naked eye--like earthworms and some insects. Other decomposers are microscopic
in size. Decomposers recycle nutrients in your garden ecosystem.
Ecosystem Balance and Imbalance
A healthy garden ecosystem will reach a balance between producers, consumers, and
decomposers. With minimal disturbance your garden ecosystem is balanced and all
nutrients are recycled.
Increasing inputs or outputs may imbalance your garden ecosystem. Inputs by
gardeners like fertilizers or pesticides can throw the garden ecosystem out of
balance. In addition, outputs such as removing flowers, vegetables, or leaves
from your garden depletes your ecosystem of nutrients. The more inputs and
outputs, the greater the overall imbalance of the system.
What inputs can throw your garden ecosystem out of balance?
A large imbalance in your garden ecosystem may cause environmental damage or
degradation and adversely affect water quality in your community.
To protect the environment and water quality you should use best management
practices (BMPs), which are defined as implemented strategies that eliminate or
minimize environmental pollution. BMPs are designed to be compatible with good,
sound garden management. BMPs can protect the environment without compromising
your garden ecosystem.
Pest Management BMPs
Pesticide use in your garden ecosystem must be done with care. Keep in mind that
pesticides may kill beneficial insects or plants along with the insect pests or
weeds. These beneficial organisms help reduce pressure from other pests and keep
your garden ecosystem healthy.
Pest management BMPs you should implement in your garden include:
- Create a garden with diversity.
Know what is in your garden!
- Plant a combination of different types of plants in your garden to create
a balanced ecosystem.
- Annuals and perennials.
- Woody and herbaceous.
- Evergreen and deciduous.
- Tall trees and shrubs, short trees and shrubs, short plants, and ground
- Rotate all plants to outsmart potential pests and minimize the threat of soil
Maximize conditions for healthy plant growth.
- Identify your garden plants. Learn what growth conditions favor their
- Positively identify your insect pests.
- Positively identify your weed pests.
Protect beneficial insects.
- Space plants to allow ample root and top growth at maturity.
- Group plants according to water needs and water appropriately.
- Choose plants suited to your climate.
- Site plants according to light requirements--sun or shade.
- Choose plants resistant to diseases and insects common to the area.
Use the most environmentally sound solution to solve problems.
- Learn to recognize the eggs and larvae of beneficial insects so not to
- Develop garden habitats to ensure a positive environment for beneficial
Use pesticides correctly.
- Use biological controls for insects.
- Use insect traps.
- Live with a low level of plant damage.
- Use nontoxic solutions to pests.
Store and dispose of pesticides properly.
- Follow pesticide label directions for rate, application, and safety.
- Match pesticide with pest.
- Use correct application rate.
- Buy only what you need.
Nutrient Management BMPs
- Buy in small quantities.
- Store in secured area.
- Dispose of in accordance with federal, state, and local
Adding fertilizers to your garden ecosystem can cause serious imbalances.
Fertilizer should be added only in the amounts needed and in a form and manner
that makes nutrients available to plants.
Nutrient management BMPs you should implement in your garden include:
- Compost garden organic materials.
Build a healthy soil.
- Retain dead plant materials such as leaves and seed free weeds in the
- Create nutrient rich organic material.
- Reduce materials sent to landfills.
Test soil before applying fertilizers.
- Add organic matter such as compost to enhance structure, aeration, water,
and nutrient holding capacity of the soil.
- Prepare soil correctly.
- Maintain a slightly acid soil (pH 6.0 to 6.5).
- Build a biologically active, healthy soil through regular additions of
- Grow annual cover crops to provide additional organic matter.
Apply correct type and rate of fertilizers based on soil test.
- Soil tests will measure the amounts of plant nutrients already available
in the soil.
- Nitrogen (N), phosphorus (P), potassium (K), and sulfur (S).
- Soil tests also measure pH and percent of organic matter.
- Soil samples should be taken to a depth of 12 inches.
Time fertilizer applications correctly.
- Types of fertilizers.
- Organic fertilizer
- Manure, compost, cottonseed meal, blood meal, and bone meal.
- Organic fertilizers supply necessary plant nutrients while improving the soil
structure, aeration, and water-holding capacity.
- Materials vary widely in their nutrient contents.
- Inorganic fertilizer.
- Chemically manufactured with exact nutrient content.
- Easy to apply, need relatively small amounts.
- Reduces loss of nutrients into the environment by applying at exact
- Rates of fertilizer should provide nutrients only up to the level needed by
the plants being grown.
Erosion Control BMPs
- Supply fertilizer only as needed by plants.
- Apply at correct growth stage or time of year.
Imbalances that lead to soil erosion from your garden may damage the surface
water quality of nearby rivers, lakes, ponds, and streams.
Erosion control BMPs you should consider in your garden include:
- Protect your soil surfaces vulnerable to erosion.
Improve your soil structure.
- Bare soil surfaces are vulnerable to erosion.
- Mulches reduce erosion.
- Organic mulches include bark, sawdust, straw, and/or grass
- Inorganic mulches include permeable or impermeable plastic sheeting and/or
- Cover crops such as oat and clover reduce erosion.
- Reduce intensity of water droplets on soil surfaces through protection by
mulch and sprinkler management.
Perform tillage operations when appropriate.
- Helps soils resist erosion processes.
- Addition of organic matter increases soil water-holding capacity and improves
- Dead plant materials--leaves, grass clippings.
- Waste products--sawdust.
- Tilled in cover crops.
Water Management BMPs
- Tilling wet soil damages soil structure.
Excess water use may result in nutrient leaching below the effective rooting
depth of plants. This breaks the nutrient cycling within the garden ecosystem.
Pesticide or nutrient leaching in your garden ecosystem also adversely affects
Water management BMPs you should implement in your garden include:
- Use only as much water as necessary.
Design your garden irrigation system for maximum efficiency.
- Repair all leaks in hoses and faucets.
- Apply water only when plants require irrigation; don't water too often.
- Apply only as much water as needed; never over-water.
- Water enough to saturate soil only through the plant root zone.
- Reduces leaching of nutrients and pesticides.
- Apply water at a rate that can be absorbed by soil--avoid runoff.
- Drip lines and directed pop-up sprinklers apply water exactly and
- Strive for uniform water application.
- Water only areas containing plants, not sidewalks, decks, parking lots, or
To protect the environment, your garden management program must consider BMPs for
pest management, fertilizer management, erosion control, and water management.
Utilization of the BMPs presented in this brochure will make you a steward of the
environment. In most cases these BMPs will not increase your costs. In fact you
will have a healthy garden with a balanced ecosystem. Remember that your garden
management system should be environmentally friendly.
This brochure, WQ-29, was prepared by R. L. Mahler, J. Robbins,
and K. A. Loeffelman, Soil Science Division, University of Idaho, Moscow, Idaho
83844. Robbins is the Extension Agricultural Agent, Blaine County, Hailey, ID.
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All contents copyright © 1997-2003.
College of Agricultural and Life Sciences, University of Idaho.
All rights reserved.
Revised: January 3, 2003