Soil and water
2015...International Year of Soils.........
According to IYS (International Year of Soils) monthly leader Gary Pierzynski, “soil is a great water purifier. There are three ways that soil cleans water: physical, chemical and biological.” Here are some facts from Pierzynski, a soil science professor at Kansas State University.
- Physical: the particles of soil act like a filter. The ideal soil has a distribution of pore sizes so it can filter water, while also allowing the water to pass through the soil.
- Chemical: soil particles have a negative charge! That means that positive ions like calcium, magnesium and potassium can all be removed from passing water and retained by the soil. This is good, because each of these ions is a nutrient for plants! Some contaminants can be removed by this mechanism as well.
- Biological: soil is the largest bioreactor on the planet. Within the soil, bacteria and fungi transform and decompose certain chemicals. Soil microbes can change organic forms of nitrogen into ammonium ions—and even into nitrogen gas. They can also decompose some organic pollutants!
As part of their celebration of IYS, SSSA is developing a series of twelve 2-minute educational videos. April’s Soils Clean and Capture Water video can be viewed at www.soils.org/iys/monthly-videos. Educational materials can be viewed at www.soils.org/iys by clicking on the April tab.
Below is an excellent article on the good reasons for mulching a garden. It was prepared by Bob Faris who has received training through Colorado State University Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County, Colorado.
Add compost, organic matter to garden to work winter magic
Here's the question:What should I do to prepare my garden soil for winter?
And here is the answer: Imagine holding over 200 billion living organisms in your hand! One cup of soil contains approximately 200 billion bacteria, 20 million protozoa, 100,000 meters of fungi, 100,000 nematodes, and 50,000 arthropods. Your soil is alive! Of the 1 percent to 5 percent organic matter found in your garden soil, 0.2 percent includes living organisms. The harvest you enjoy can be amplified by working together with these billions of friends beneath the soil surface.
These soil organisms can be grouped into three categories: organisms that are beneficial to plants — directly or indirectly; neutral organisms — those whose activities have no affect on plants; and organisms that are harmful to plants. The organisms in your soil form what is known as the "soil food web" and is the basis for healthy living soil.
So what should be done to support these living organisms and how can we help them to remain healthy and maintain a beneficial sub-surface environment? These organisms need to be fed. Adding compost and organic matter to your garden will accomplish this. Lightly broadcasting a cover crop in late fall and allowing these plants to overwinter will provide organic matter to your soil. A blend of buckwheat, peas, vetch, and rye will create a green manure feeding your soil organisms. Avoid rototilling or the use of pesticides. Overuse of pesticides can be harmful to many of these members of the food web, and rototilling will destroy the mycorrhizae and soil structure.
For more information about both the soil food web and how to maintain a healthy living soil, read CSU Extension Garden Notes No. 212 "The Living Soil" at www.cmg.colostate.edu.
Note: This is information from the Soil Science Society of America and it has an excellent website. By all means, use the links to learn more.
Soils are a major contributor to clean water and keeping water in its place. But, as cities developed on former forest and prairie land, humans engineered ways to “manage” the water flow. However, many cities realize that working with nature, and its soil, is healthier and less expensive for the environment. Here are some tips from the Soil Science Society of America (SSSA) about “what can the average citizen do?”
Step 1: Conserve the soil
Like any sustainable strategy, the most important starting point is conservation. Conserving our green spaces and caring for the soil that’s already in place is central to creating healthy ground for improved stormwater management. This includes reducing soil compaction and erosion, and promoting soil health. Strategies for improving soil include:
- Amending soils with compost
- Letting leaves and grass clippings decompose in place to restore soil organic matter
- Using compost socks and berms to prevent erosion in areas under construction
- Planting trees and native plants in areas where soil is bare
Step 2: Install a rain garden or other green infrastructure feature
Residential rain gardens not only reduce flooding in your neighborhood but can increase property values and are a charming landscape feature. Other green infrastructure tools for reducing runoff include use of rain barrels or cisterns, disconnecting downspouts, and installing green roofs. Many municipalities have developed incentive programs to share the cost of construction.
Step 3: Create a community of water savers
The impact of these strategies will be enhanced if they are implemented on a community level. Clustering rain gardens in a designated area such as a neighborhood block allows pooling of resources, the potential for shared maintenance, and a greater collective impact on runoff.
Tips for inspiring community stormwater projects:
Communicate! Talk to your neighbors or hold a community event to educate the neighborhood about the issues surrounding stormwater runoff.
Collaborate! Reach out to landscapers, nurseries, and other vendors who might be willing to give you bulk discounts for group projects. Local non-profits or government agencies may also be helpful.
Educate! Post signage in yards or parking strips where projects have been built to bring attention to the economic and environmental values of green infrastructure.
Share! Organize a tour of your rain garden project to inspire other communities to create their own projects.
For more information on using your soil more wisely, visit soils.org/discover-soils/soils-in-the-city. Topics under Soils in the City include Community Gardens, Green Infrastructure, Green Roofs, and Soil Contaminants. SSSA also has an informational blog about soils, called Soils Matter, athttp://soilsmatter.wordpress.com/