Reducing phosphorus losses from surface-irrigated fields: emerging polyacrylamide technology

Lentz, R.D. and Sojka, R.E. and Robbins, C.W. (1998) Reducing phosphorus losses from surface-irrigated fields: emerging polyacrylamide technology. Journal of Environment Quality. 27:305-312.

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Abstract

Most P losses from surface-irrigated fields occur via runoff, are
associated with eroded sediment, and can be minimized by eliminating
irrigation-induced erosion. A convenient new practice that eliminates
furrow irrigation-induced soil losses uses a high molecular weight,
anionic polyacrylamide (PAM) applied to initial irrigation inflows.
We hypothesized that, compared to control furrows, PAM treatment
would reduce field losses of ortho P, total P, NO3, and lower tailwater
chemical oxygen demand (COD). Two PAM treatments were tested:
I10 applied 10 mg L-1 PAM only during the furrow advance (i.e., the
application was halted after runoff began) and C I applied 1 mg L-1
PAM continuously throughout the irrigation. Soil was Portneuf silt
loam (coarse-silty, mixed, mesic Durixerollic Calciorthid) with 1.6%
slope. Initial inflows were cut back from 23 to 15 L min-1 after 1.5
to 6 h. Total soil loss over four irrigations was 3.06 Mg ha-1 for control
furrows vs. 0.33 (C1) and 0.24 (I10) for PAM-treated furrows. Ortho-P
and total P concentrations in control tailwaters were five to seven
times that of PAM treatments, and COD levels were four times those
of PAM treatments. Runoff in controls was two times that of PAM-treated
furrows. PAM-I10 lowered furrow stream nutrient concentrations
more than did PAM-C1 , but owing to disparities in runoff, the
two treatments produced similar cumulative sediment and nutrient
mass losses. The PAM is effective, convenient, and economical, and
greatly reduces P and organic material (COD) losses from surface-irrigated
fields.

Item Type:	Article
NWISRL Publication Number:	0962
Subjects:	Irrigation > Furrow irrigation > Runoff losses > Nutrients Polyacrylamide (PAM) > Water-soluble PAM (WSPAM) Mass Import - autoclassified (may be erroneous)
Depositing User:	Users 6 not found.
Date Deposited:	20 Nov 2010 21:54
Last Modified:	18 Nov 2016 18:40
Item ID:	694
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/694