Home' Grower : October 2009 Contents The South Australian Grower -- October 2009 7
Calcium cornerstone for optimum soils
By KATIE WEBSTER
THE role of calcium in soil
management is often overlooked.
Calcium affects the manageability
of clay in soils and ideal levels can
promote good soil structure, more
efficient infiltration and percolation of
water, and displacement and leaching of
Problems such as sodicity, an excess
of sodium ions in the soil, and salinity,
an excess of sodium chloride, can be
improved with good use of calcium
It is possible to determine whether a
soil will benefit from additional calcium
with a soil test that reports the
percentage of major exchangeable
cations -- calcium, magnesium, sodium,
potassium, and in acidic soils, hydrogen.
As a rule of thumb, an ideal soil will
have around 60 to 70 per cent
exchangeable calcium, 10-15pc
magnesium, up to 5pc potassium and
less than 2pc sodium. Soils with less
than 50pc exchangeable calcium or
more than 2pc sodium are certainly
candidates for improvement.
If a soil test shows any of these
conditions, it is worth getting further
advice from an agronomist on the best
way to achieve more balanced soil.
Other signs that soil may benefit from
additional calcium are high levels of
sodium chloride, poor infiltration with
pooling of water on the soil surface, and
the occurrence of sodicity, which can
cause the soil to move quickly from
being sticky and unmanageable when
wet, to hard-set and dense when dry.
These conditions can hinder plant
performance and make tillage operations
more costly and difficult.
The percentage of exchangeable
cations in soil can be changed by
increasing the concentration of one or
some of these cations in the soil
solution, so to bring about changes a
source of soluble calcium will be
Solubility varies -- for example, about
1000 litres of water is needed to
dissolve 2.5 kilograms of gypsum, and
further water is required to leach the
displaced cations from the soil. The
relatively low solubility of some
amendments can make management a
longer term exercise.
These are not the only options
however, and liquid calcium sources can
act much more quickly in the soil. For
example, the liquid calcium amendment
'CalSap' has a solubility 10,000 times
that of gypsum with effects on the soil
measurable within weeks.
Even where the preferred longer term
plan would be to use gypsum, these
more rapidly acting liquids can be used
to conduct an on-farm trial to quickly
confirm that calcium amendments will
have the desired effect.
Following soil amendment with an
appropriate calcium source, growers
should notice a change in the balance of
exchangeable cations in their soil tests,
improved soil structure, better
infiltration of water, and alleviation of
conditions such as sodicity and salinity.
With improved soil conditions, plants
will have the opportunity for improved
root growth, greater uptake of
nutrients, and better performance. In
some cases, improved fertiliser use
efficiency may be seen.
Calcium is a vital element in the soil,
and it is worth checking out whether
the performance of the crop will benefit
from calcium amendments.
Details: Katie Webster, EcoResearch 08 8339
By RICHARD MULCAHY
AUSVEG Chief Executive Officer
IAM pleased to update you on important
issues facing the Australian vegetable and
potato industry. This new CEO column from
AUSVEG will provide a valuable tool to keep you
informed of issues that directly affect the
horticulture industry nationally.
In an important recent development, Deputy
Prime Minister Julia Gillard intervened in the
proposed Horticulture Industry Award changes.
AUSVEG welcomes this development and has
been in close contact with the office of the
Deputy Prime Minister and our State members
to work towards this development.
Ms Gillard has referred the proposed award
back to the Australian Industrial Relations
Commission for review with the implementation
of new award provisions delayed until July 1,
2010. This coincides with Fair Work Australia's
first minimum wage review.
In her letter to the AIRC, Ms Gillard requested
that: "The Commission should enable employers
in the horticulture industry to continue to pay
piece rates of pay to casual employees who
pick produce as opposed to a minimum rate of
pay supplemented by an incentive based
"Where a modern award covers horticultural
work, the Commission should have regard to
the perishable nature of the produce grown by
particular sectors of the horticulture industry
when setting the hours of work provisions for
employees who pick and pack this produce."
In addition, Ms Gillard urged the commission
to provide for roster arrangements and working
hours that are sufficiently flexible to
accommodate seasonal demands and
restrictions caused by weather as to when work
can be performed".
Meanwhile, the focus has moved to the next
stage of the process with the AIRC inviting
growers to submit award submissions to
replace the current Fruit and Vegetable Growing
Industry Award from January 1, 2010.
The AIRC Full Bench says it will schedule time
this year for any application received to ensure
it is ready for the start of next year.
Nonetheless, although timelines for submissions
and appearances are still being finalised,
growers considering workplace agreements
should contact their IR Advisor as soon as
possible as agreements take a minimum of four
weeks to process.
New workplace agreements will provide
growers with some certainty for up to four
years, despite possible, changes that come into
place on July 1 next year.
With regards to the new award due to be
introduced in mid 2010, AUSVEG is consulting
with other sections of the horticulture
community and conducting further research into
the impacts of the new award and any policy
implications they might have.
I look forward to keeping you updated on
developments regarding the award and other
issues facing the vegetable and potato industry.
Details: AUSVEG 03 9544 8098, ausveg.com.au
Veg body concerned by hort award changes
Improves soil structure, water
Helps reduce salinity
Liquid calcium fast-acting option
AT A GLANCE
Himac BX Chippers
Phone for a
1800 888 114
Wholesale Enquiries Welcome
Damian 0408 852 690
Tim 0427 182 062
ADELAIDE PLAINS FEEDLOT
Carbon Nitrogen 14:1
Direct from source
Links Archive September 2009 November 2009 Navigation Previous Page Next Page