|Koehn, A - UNIVERSITY OF IDAHO|
|Peckenpaugh, R - USDA-ARS (RETIRED)|
Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2002
Publication Date: November 1, 2003
Citation: Lentz, R.D., Koehn, A.C., Peckenpaugh, R.E. 2003. Managing erosion and infiltration in steeply sloping irrigation furrows with polyacrylamide. Proceedings of Soil Science Society Of America Annual Meeting, November 2-6, 2003, Denver, Colorado. 2003 CD-ROM. Technical Abstract: Most anionic-polyacrylamide (PAM) application comparisons in furrow irrigation have been done using furrows with <2% slopes. Results from such comparisons may not be valid for steeper furrows because of increased flow shear. We evaluated the efficacy of different PAM application methodologies on Portneuf silt loam (Durinodic Xeric Haplocalcids) with 4.7% sloping furrows. Treatments included a control, 10 mg/L PAM dissolved in irrigation water during furrow advance (P10), 3 mg/L PAM applied continuously in the irrigation water (C3); P10 followed by continuously applied 0.25 mg/L PAM (P10+C.25), and 1 kg PAM/ha applied as a granular patch (patch). We monitored two irrigations on freshly formed, nonwheel- and wheel-tracked furrows. The P10 and P10+C.25 treatments produced identical results. The P10 and C3 treatments reduced sediment loss by greater than or equal to 99% while the patch treatment reduced sediment loss by 71%, relative to controls (2.3 Mg/ha). Mean runoff sediment concentration among treatments differed significantly: controls (5.7 g/L) > patch (2.3 g/L) > P10 (0.01 g/L). Net infiltration, given as a percent of total inflow, also differed between treatments: controls (65%) < patch (76%) < P10 (87%). Infiltration rates during the first 12 h of irrigation were greatest for C3. Thus, C3 furrow advance times were significantly slower than for the other treatments (1.3x to 2.2x). On 4.7% slopes, P10 controlled erosion and enhanced infiltration more effectively than the patch; whereas these treatments were reported to be equally effective on 1-2% slopes.