Sediment and phosphorus transport in irrigation furrows

Bjorneberg, D.L. and Westermann, D.T. and Aase, J.K. and Clemmens, A.J. and Strelkoff, T. (2006) Sediment and phosphorus transport in irrigation furrows. Journal of Environmental Quality. 35:786-794.

PDF 1184.pdf Download (631kB)

Abstract

Sediment and phosphorus (P) in agricultural runoff can impair
water quality in streams, lakes, and rivers. We studied the factors
affecting P transfer and transport in irrigated furrows in six freshly
tilled fallow fields, 110 to 180 m long with 0.007 to 0.012 m m' slopes
without the interference of raindrops or sheet flow that occur during
natural or simulated rain. The soil on all fields was Portneuf silt loam
(coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcids).
Flow rate, sediment concentration, and P concentrations were monitored
at four, equally spaced locations in each furrow. Flow rate decreased
with distance down the furrow as water infiltrated. Sediment
concentration varied with distance and time with no set pattern. Total
P concentrations related directly to sediment concentrations (r2 =
0.75) because typically >90% of the transported P was particulate P,
emphasizing the need to control erosion to reduce P loss. Dissolved
reactive phosphorus (DRP) concentrations decreased with time at a
specific furrow site but increased with distance down the furrow as
contact time with soil and suspended sediment increased. The DRP
concentration correlated better with sediment concentration than extractable
furrow soil P concentration. However, suspended sediment
concentration tended to not affect DRP concentration later in the irrigation
(>2 h). These results indicate that the effects of soil P can be
overshadowed by differences in flow hydraulics, suspended sediment
loads, and non-equilibrium conditions.

Item Type:	Article
NWISRL Publication Number:	1184
Subjects:	Irrigation > Furrow irrigation > Runoff losses > Sediment Mass Import - autoclassified (may be erroneous)
Depositing User:	Users 6 not found.
Date Deposited:	20 Nov 2010 21:49
Last Modified:	01 Nov 2016 15:47
Item ID:	34
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/34