News on Soil Health for Backyard Conservation
Soil is no longer something to just brush off. Beneath the gardener’s fingernails and always underfoot, our soil is a dynamic resource, ecosystem, and building block for all living things.
Recognizing soil’s importance and unique role, the 68th United Nations General Assembly declared 2015 the International Year of Soils (IYS) and nominated the Food and Agriculture Organization of the United Nations (FAO) to implement IYS.
The objectives of the International Year of Soils include raising awareness about the importance of soil to human life, promoting sustainable soil management activities to develop and maintain healthy soils for different land users and population groups, and advocating for soil monitoring at all levels (global, national, and regional).
“Soil organisms use biological, chemical, and physical processes to stabilize readily-decomposable organic matter so it will persist in soil for decades or centuries,” states Rodale Institute’s Chief Scientist Dr. Kristine Nichols. Much like a sponge, healthy soil is full of irregular-size pores left by burrowing worms, mammals, and insects that facilitate the decomposition of dead plants and animals and the disintegration of rocks. It absorbs water, sequesters carbon, and nourishes gardens.
In Soil—A Precious Natural Resource, the Swiss Confederation reports that soil erosion and desertification occurs in 168 countries from the approximately 24 million tons of soil that is washed or blown away each year.
Boosting Backyard Soil Quality
“Areas near large deserts in Africa, the Middle East, and Southern Asia are being overtaken by deserts due to poor land use decisions and climate change,” says McHenry–Lake County Soil and Water Conservation District Soil Scientist Bob Oja. “Some of the more severe cases [of soil loss] are occurring with the deforestation of tropical areas,” Oja said. These deforested areas are productive for agriculture for short periods, but are very susceptible to water erosion and the quick loss of organic carbon.” Oja notes that our area is suffering from declining soil quality due to erosion and compaction.
The U.S. loses nearly 2 billion metric tons of topsoil per year according to the U.S.D.A. Natural Resources Conservation Service. Tilling increases soil exposure to oxygen which ‘burns’ organic matter, making soil more susceptible to erosion. Increased construction and compaction by large equipment compresses roots, reduces permeability, and increases runoff to local streams.
According to the U.S. Environmental Protection Agency, the Gulf of Mexico receives excess nitrogen and phosphorous from a network of watersheds that extend from Montana to Pennsylvania that culminate in the Mississippi River. Soil erosion, combined with animal waste, sewage, and fertilizer runoff that increases with floods, contribute to algal blooms that deplete dissolved oxygen essential to aquatic life.
In 2015, the hypoxic area (“dead zone”) in the Gulf of Mexico surpassed its 5-year average by covering 6,474 square miles. FarmFutures.com reports that: Heavy rains earlier this summer might be a contributor to a dead zone in the Gulf of Mexico that is larger than last year's, the National Oceanic and Atmospheric Administration (NOAA) said this week.
Also called hypoxia areas, dead zones are caused by nutrient runoff from agricultural and other human activities in the watershed and are "highly affected" by river discharge and nitrogen loads, NOAA said. Excess nutrients stimulate algae growth, which later sinks, decomposes, and consumes oxygen. It's estimated that there are more than 550 dead zones occurring annually worldwide.
After the departure of glaciers 12,000 years ago, silty clay loam named Elliott, Markham, Ashkum, and Morley soils were formed in much of Lake County. Low and wet organic soils consisting of 3-10’ or more of decomposing plants in muck or peat made up Houghton soils. Less common Zurich, Grays, and Barrington developed in 2-3’ of silty material underlain by deposits of silt and sand. Typically named after the nearest town or stream where they were first found, Barrington soils were originally mapped in the vicinity of modern-day Barrington.
Since 1935, Natural Resource Conservation Service (NRCS) has been promoting voluntary programs to reduce nutrient loss from soil; however, it wasn’t until 1977 that NRCS conducted National Resources Inventories (NRI) to monitor soil. Using 800,000 sampling units throughout the U.S. to track land use, NRIs were initially conducted every five years.
Since 2000, these inventories have been conducted annually with county-based Soil and Water Conservation Services surveying tolerable soil loss each spring. From 2000 to 2015, tolerable soil loss figures in McHenry County dropped from 90 percent of farmers meeting conservation criteria to 80 percent. While the investment of time and money required to conserve soil on larger properties offers long-term benefits, most local farmers rent the land they cultivate and need to be mindful of adding to their financial burdens.
“The best way to protect our soils from wind and water erosion is to keep them well-vegetated,” says Bob Oja. Dr. Nichols agrees, noting the importance of maintaining a yard and garden with a variety of plants and trees instead of a monoculture which can leave soil bare part of the year. Putting away the tiller enables healthy soil to maintain a porous structure that reduces flooding and water erosion, while amending a garden with compost or a yard with liquefied compost ‘tea’ can allow soil to use nutrients more efficiently. Local soil health contributes to the quality of our water, the beauty of our landscape, and the health of our residents and everyone who lives downstream.
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Here’s the dirt on the matter and material beneath our feet.
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April Anderson is a naturalist and freelance writer who can be contacted at firstname.lastname@example.org.