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ARS Home » Pacific West Area » Pendleton, Oregon » Soil and Water Conservation Research » Research » Publications at this Location » Publication #82576

Title: MICROBIOTIC CRUST INFLUENCE ON SOIL HYDROLOGY AND EROSION

Author
item Williams, John

Submitted to: Ecology and Management of Microbiotic Soil Crusts
Publication Type: Proceedings
Publication Acceptance Date: 7/1/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Grooves can be ripped in soil containing recently planted wheat. This technique, in which the grooves are ripped following contour lines, provides protection against erosion in seasonally frozen soil. In this paper and accompanying poster, we discuss preliminary findings and present an overview of this conservation technique. In the Pacific Northwest our worst erosion occurs during winter months with light, slow rainfall falling on thawing soil. Long, steep slopes and minimal plant cover are characteristics of landscapes most impacted by this type of erosion. Winter wheat-summer fallow cropping practices, the most common farming practice in this region, makes these conditions worse. We put together information that discusses contour ripping frozen soil planted to winter wheat in the Pacific Northwest. This information shows that slope length is effectively shortened and runoff decreased when this technique is used. The channels keep water on the slope, reduce runoff and erosion, and allow the water to percolate into the soil. This process increases the amount of water stored in the soil profile for later crop use. Contour tillage can be done without significant damage to crop yield or an increase in disease. However, effectiveness decreases rapidly with each storm following contour trenching. The technique is best used on slopes with deep soil for water storage and, also, slope where erosion is known to be a problem.

Technical Abstract: Microbiotic crusts are common components of arid and semiarid rangelands. They contribute to heterogeneous patterns of soil and plant community development. The physical and chemical attributes of these crusts influence soil hydrology and erodibility. Microbiotic crust influence on soil hydrology is not consistent and depends upon degree of crust development, bio- type, and intrinsic soil characteristics. They have been attributed with increasing, having no effect, and decreasing infiltrability. The erosion processes of detachment and deposition are influenced by the presence of microbiotic crusts, even in early developmental stages. Their effect on reducing erosion by water is dependent upon their degree of development. They unequivocally reduce wind erosion. Many inconsistencies in conclusion can be avoided by standardizing data collection methods. Standardization will aid in clarifying the role of microbiotic crusts in plant community development and the consequent effect on erosion and hydrology. In the this paper, I summarize the literature relative to microbiotic crust influence on arid and semiarid land soil hydrology and erosion.