Solute response to changing nutrient loads in soil and walled ceramic cup samplers under continuous extraction

Lentz, R.D. (2006) Solute response to changing nutrient loads in soil and walled ceramic cup samplers under continuous extraction. Journal of Environmental Quality. 35:1863-1872.

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Abstract

This report evaluates a vacuum-assisted walled percolation sampler
preconditioned in soil, and examines the dynamic response of leachate
solutes. The 20-cm walled percolation sampler extracted soil water
under continuous tension via a ceramic cup collector embedded in a
silica flour layer, whose upper surface interfaced with field soil. In
the laboratory, alternating solutions with high and low NO3-N (232
or 3.6 mg L-1), molybdate-reactive P (MRP) (1.75 or 0.0 mg L -1), K+
(568 or 3.6 mg L-1), and Br- (9.6 or 0.0 mg L-1) concentrations
were delivered directly to the (i) sampler ceramic cup; (ii) silica flour bed
surface, or (iii) 12-mm soil layer placed over the silica flour bed. For
alternating input solutions delivered to the silica-flour bed surface, (i)
solute breakthrough (95% equivalency) occurred in 4 pore volumes and
was the same for both the high and low concentration input phases of the
application, and (ii) concentrations of NO 3-N, Br-, and MRP in cumulative
extracted water volumes were within 5% of those in corresponding
input volumes. Alternating nutrient loads from high to low
levels in the fixed flow rate input waters caused excess MRP (L6 times
that in the high concentration MRP solution) to leach from the calcareous
soil. The dynamic character of P transport in K-fertilized soils deserves
further study and may have important environmental implications.

Item Type:	Article
NWISRL Publication Number:	1188
Subjects:	Soil > Chemistry Research methodology Mass Import - autoclassified (may be erroneous)
Depositing User:	Users 6 not found.
Date Deposited:	20 Nov 2010 21:49
Last Modified:	01 Nov 2016 15:42
Item ID:	37
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/37