Furrow erosion was recognized as a serious problem damaging cropland 40
years ago (Israelson et al., 1946), and attempts to quantify soil loss in
relation to furrow stream size and slope were made then and in the following
few years (Gardner and Lauritzen, 1946; Mech, 1959). However, little attention
was given to these studies, and the furrow erosion problem continued without
much effort to correct it for another 25 years. In the early 1970's water
quality legislation was directed towards reducing sediment, nutrients and
biocides in irrigation return flows. As scientists began to develop methods
to improve the quality of irrigation return flows in response to this legislation,
some questions were raised about the sources of these pollutants. Brown et el.,
(1974), and Carter at al., (1974) reported sediment and phosphorus inflows,
outflows, and balances for two large irrigation tracts in south central Idaho.
They found large quantities of sediment and associated phosphorus were being
lost from many irrigated fields. Research has progressed during the life of
the STEEP project, and much new information about erosion and sediment loss
has been reported both at Kimberly, Idaho, and Prosser, Washington. This paper
is a summary of the progress made towards understanding and controlling irrigation
erosion and sediment loss