Percolation phosphorus losses in calcareous furrow-irrigated soils

PERDIDAS DE FOSFORO DE PERCOLACION EN SUELOS CALCAREOS IRRIGADOS CON SURCOS

Lentz, R.D. and Westermann, D.T. (2001) Percolation phosphorus losses in calcareous furrow-irrigated soils. pp. 90-95. In: Brown, B. (ed.) Proc. Of the Western Nutrient Management Conference. USA-UT-Salt Lake City, 2001/03/08-09.

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Abstract

Groundwater seepage contributes to irrigation return flows and surface waters. Knowledge of
phosphorus (P) concentrations and loads in percolation water that enters the vadose zone and
groundwater is necessary to assess and manage water quality. We measured the P in water
leached below the crop root zone in a furrow-irrigated Portneuf silt loam. Vacuum operated
percolation samplers were used to monitor soil water flux, and molybdate-reactive-P (MRP) and
total P concentrations in leachate during the cropping season. The samplers were placed at 4 ft
depths at 100 ft and 500 ft across a 590-fi-long corn field that was furrow irrigated using either
conventional or PAM treatment. We found no irrigation treatment effects on cumulative
amounts of water or P leached The MRP concentrations in leachate ranged from 0.01 to 2.0
ppm and averaged 0.58 ppm during three irrigation seasons. The MRP concentrations in lower-field
leachate were nearly 10X greater than those from the upper-field. The P mass losses
during the irrigation season were less than 0.1 lb acre -J . The P concentrations in leachate were
2 to 20 times greater than ortho-P equilibrium concentrations measured in the subsoil water (i.e.
dilute CaC12 extractable ortho-P). P concentrations in drainage water appeared to be reflective
of percolate volume and soil chemistry.

Item Type:	Conference or Workshop Item (Paper)
NWISRL Publication Number:	1038
Subjects:	Irrigation > Furrow irrigation > Runoff losses > Nutrients Irrigation > Furrow irrigation > Percolation water > Nutrient losses Soil > Calcareous soil Soil > Chemistry > Phosphorous Mass Import - autoclassified (may be erroneous)
Depositing User:	Users 6 not found.
Date Deposited:	20 Nov 2010 21:56
Last Modified:	14 Nov 2016 17:32
Item ID:	926
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/926