Abstract
Each year in Idaho and Oregon, 351,000 Mg of precipitated
calcium carbonate (PCC) (a byproduct of sucrose
extraction from sugarbeet) is produced and stockpiled at
sugarbeet processing factories. Currently there are limited
disposal strategies for the PCC and these stockpiles continue
to grow over time. The simplest solution would be
to apply the PCC directly to agricultural fields each year,
however the effects of PCC on high pH soils and crop rotations
in the growing area are not well understood and
growers are understandably hesitant. Two studies were
conducted at the USDA-ARS laboratory in Kimberly, ID
to determine the effects of PCC application to a high pH
silt loam soil on a sugarbeet, dry bean and barley rotation
and soil properties. For each study, three PCC treatments
(rate and timing) and an untreated control were evaluated.
The PCC had no effects on crop yields and most soil properties.
The only common effect of PCC treatments was an
increase in soil phosphorus (P) concentrations compared to
the control, indicating the PCC can serve as a P fertilizer.
For all three crops in this study, PCC was applied at rates
that resulted in applied P rates that were 1.6 to 5.3 times
greater than even the highest published recommended agronomic
P rates. Compared to the control, bicarbonate soil
P concentrations increased by 139% and 84% when PCC
was applied at a rate of 87.9 Mg ha-1 in Study1 and Study
2, respectively. The PCC used in this study can safely be
applied at rates up to 87.9 Mg ha-1 to heavier textured alkaline
soils in the local growing area. Disposing of PCC
in this way represents a viable strategy for reducing PCC
stockpiles.