Water

Irrigation, Runoff and Infiltration

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The experimental set-up from 2004-2006 in the Russell Ranch run-off plots.

In 2003, research was initiated at Russell Ranch to evaluate the economic and environmental effects of different farming practices. A major goal of these studies is to assess the potential of winter cover cropping and conservation tillage to reduce runoff and the associated losses of sediment, nutrients and pesticides in furrow-irrigated systems. Researchers have found that cover crops substantially reduce winter runoff by increasing infiltration. Increased infiltration is also observed the season after cover crop in-corporation. By decreasing run-off quantity, cover crops reduce the export of constituents, such as dissolved organic carbon, which is involved in the formation of harmful disinfection by-products in drinking water. Furrow irrigation may not be optimal for organic agriculture because enhanced infiltration leads to high water use and percolation. Research to develop recommendations for best management practices in different seasons, field configurations, and crop types is continuing at Russell Ranch and surrounding farm sites. See more information about the project at the SAFS website.

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Effect of cover crops and no-tillage practice on dissolved organic carbon export during a 2-day pre-irrigation in 400 and 1200 ft long fields under standard tillage (ST), standard tillage after cover crop incorporation (CC), and no-tillage (NT) (Burger et al. 2008).