Agriculture Reference
In-Depth Information
Figure 11.6
. Ionic composition, expressed as charge equivalents, of soil water collected
with tension samplers at 1.2 and 1.8 m depths, and of precipitation (data from Fig. 11.5).
The soil water samples represent hydrochemical changes in precipitation as it percolates
through soils without added fertilizer, lime, and organic wastes. Soils at the 1.2-m depth had
no detectable carbonate minerals at the three MCSE Deciduous Forest sites, whereas those
collected from 1.8-m depth contained abundant carbonate minerals (8 wt % calcite and 9 wt
% dolomite: Jin et al. 2008a). Cond. = specific conductance; ANC = acid neutralizing capac-
ity, due almost entirely to bicarbonate (HCO
3
-
) alkalinity in these waters. Soil water at 1.2
m based on 98 samples taken at three of the KBS Deciduous Forest sites during Mar-Nov
from 2000-2003 (data from Kurzman 2006). Soil water at 1.8 m based on 35 samples from
a monolith lysimeter located near the MCSE, within the 3BC2 horizon, collected during
Mar-May from 2003-2004 (data from Jin et al. 2008a).
for measuring the concentration of solutes in percolating water leaving the rooting
zone, and when combined with water budget estimates of drainage, they provide an
estimate of total hydrologic solute loss. A comprehensive analysis of major solute
hydrochemistry in soil water collected from tension samplers located just beneath
the rooting zone of MCSE systems (Kurzman 2006) shows that the hydrologic
loss of solutes varies with vegetation and agronomic management. The total ionic
