Author
 |
TROUT, THOMAS - USDA-ARS |
|
Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/5/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Furrow irrigation can cause erosion. Irrigation-induced erosion is a serious problem in some states that has resulted in reduced crop yields. Measurements to evaluate furrow erosion have generally measured only the average erosion rate for the whole fields. However, erosion theory predicts that the furrow erosion is much larger at the inflow end of the field compared to the outflow end. The purpose of this study was to quantify soil erosion and sediment deposition distribution within furrow irrigated fields. Within-field sediment transport measurements on two silt loam fields in southern Idaho showed that erosion rates at the inflow one-quarter length of uniformly-sloped furrows were 6-20 times greater than average rates for the fields. Over half of the soil that eroded from the inflow end of the furrows deposited on the lower positions of the field where furrow flow rates were lower. The measurements demonstrate the need to measure erosion rates near the inflow ends as well as for the whole field. They also help explain visual erosion damage to the inflow ends of fields. Technical Abstract: Furrow irrigation-induced erosion is a serious problem in some states that has resulted in reduced crop yields. Most furrow erosion assessments have been based on measured sediment discharge from the field which results in an average erosion rate for the whole field. However, erosion theory predicts that the erosion rate should decrease with distance from the head (inflow) end of the furrow. The purpose of this study was to quantify soil erosion and deposition distribution within furrow irrigated fields. Within field sediment discharge measurements on two silt loam fields in southern Idaho showed that over half of the soil that eroded from the head (inflow) end of the furrows deposited on the lower portions of the field as furrow flow rates decreased. Erosion rates at the upper quarter of uniformly-sloped furrows were 6-20 times greater than average rates from the field. The measurements demonstrate the need to measure erosion rates on the head ends as well as for the whole field, and explain visible erosion damage from field upper ends where field average erosion rates are not high. |
