Working with Hedgerows

Often farms specialize in one or a few crops creating a monoculture in their fields. This may lead to more efficient work resulting in higher economic benefits to the farmer. However, monocultures regularly result in pest infestations, a loss of biodiversity, and a reliance on external inputs such as fertilizers, pesticides, and herbicides.

So, here is where a hedgerow comes in. A hedgerow is a strip of land planted within or around the field as a place for pollinators and other beneficial insects to eat and live. These strips of land can either be weedy or planted with specifics in mind. Insect predator abundance in the field is greatest near the edges (Altieri, 1994). This means the “good” bugs are found where there is biodiversity. Seems pretty simple, right?

The hedgerow shown above has mostly California native plants and a few other drought tolerant species interspersed. Trees and larger shrubs can also be planted to encourage birds to perch and eat pests within the field. Adding sunflowers, peppers, and alyssum flowers help attract the Minute Pirate Bug and other predatory beneficial insects. Butterfly pathways can also be created for migratory species like the monarch (milkweed) and the Karner blue butterfly (wild lupine).

You don’t have to be a farmer to plant a hedgerow. Adding native flowering plants to your landscape helps reintroduce beneficial insects, pollinators, and butterflies into your garden.

Photo credit: Thank you, Nancy from SAGE – Sustainable Agriculture Education in Berkeley, CA. You can learn more about SAGE at:  http://www.sagecenter.org/.

Hydric Soils

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A hydric soil is a soil that formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part” (59 Fed. Reg. 35680, 7/13/94)

 

The definition of anaerobic for hydric soils is the “virtual” lack of oxygen, as almost no soil will become completely devoid of oxygen. We use soil morphology, mostly based on the reduction of Iron, to identify hydric soils. Iron is reduced much “lower” on the redox scale than Oxygen. In the photo above, the Iron within the soil changes to a bright orange as it comes back into contact with Oxygen.

As soil becomes waterlogged, the microbes use up O2 as part of their biological process. This can be in a little as two days in a laboratory setting and less than one week in the field. Scientists consider the “upper part” as the major part of the rooting zone, or about 6″ in sandy soils and 12″ in loamy soils.

There are several indicators used to identify the hydric soil component of a wetland on-site. Iron oxidation is one of the most visible indicators of a hydric soil. Certain criteria are also used to generate lists off-site to determine if an area is likely or not to contain hydric soils. Combined, scientists use these indicators and specific criteria to determine if an area is hydric. This data is utilized for wetland delineation and regulation.

Want to learn more about hydric soils? Visit these sites:

Natural Resources Conservation Service, Wetland Science and Soils Division

Soil Science Society of America

Society of Wetland Scientists