Deep percolation and preferential flow under conventionally and PAM-treated irrigation furrows

Flujo de Precolación Profunda y Preferencial Bajo Surcos Tratados con irrigación Convencional o con PAM

Lentz, R.D. and Westermann, D.T. and Kincaid, D.C. and Koehn, A.C. (2001) Deep percolation and preferential flow under conventionally and PAM-treated irrigation furrows. pp. 157-160. In: Bosch, D. and al, et (eds.) Proc. 2nd Int. Symp. Preferential flow: Water movement and chemical transport in the environment. USA-HI-Honolulu, 2001/01/03-05. ASAE, St. Joseph, MI.

	PDF 1037.pdf Download (151kB)
	PDF ES_1037.pdf Download (11kB)

Abstract

Water-soluble anionic polyacrylamide (PAM), a nontoxic polymer, is employed in furrow irrigation to control
soil erosion and increase infiltration. We hypothesized that post-irrigation deep percolation and preferential-flow
patterns for the PAM treatment would differ from that of the conventionally irrigated (CI) furrows. Portneuf silt
loam plots 179 m long were planted to corn and irrigated using either CI or PAM treatment. We added PAM to
advancing irrigation furrow streams at 10 ppm. Inflow rates during furrow advance were 3X greater than that of
conventionally irrigated furrows. Vacuum assisted percolation samplers at 1.2 m depth and neutron probe access
tubes were installed at locations 30 m down furrow to monitor soil water flux and soil wetting patterns. Daily deep
percolation volumes were collected after two irrigation events in 1998, and analyzed for nitrate-N and CI
concentrations. Two general patterns for daily percolation rate emerged. tinder Cl, percolation rate started high
the first day after irrigation, declined during the second and third days to a value about half that of the first day, then
rose to a second peak between 6 and 7 days after irrigation. PAM percolation rate started low on the first day after
irrigation, peaked at about twice the initial rate on day two or three, declined through day four or five, then rose to
a second peak between 6 and R days after irrigation. Water moved rapidly downward from CI furrows after
irrigation, and included bypass flow that diluted nitrate concentrations in deep percolation water. PAM treatment
inhibited initial rapid downward movement of applied water, possibly by reducing preferential flow.

Item Type:	Conference or Workshop Item (Paper)
NWISRL Publication Number:	1037
Subjects:	Irrigation > Furrow irrigation > Percolation water Percolation > Polyacrylamide Polyacrylamide (PAM) > Water-soluble PAM (WSPAM) > Percolation water Mass Import - autoclassified (may be erroneous)
Depositing User:	Users 6 not found.
Date Deposited:	20 Nov 2010 21:56
Last Modified:	14 Nov 2016 17:38
Item ID:	890
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/890