growers@sgcotton.com.au Roger Tomkins - Greenmount Press

SOIL organic carbon (SOC) is an important indicator of soil
fertility. Improved water holding capacity, greater microbial
activity and better soil structure are associated with soil
having higher SOC. Most of our cropping soils have declining
SOC due to the management practices that have operated during
the past few decades. To improve soil health, build and sustain
high agricultural productivity, we need to reverse this trend and
increase SOC.
Measuring SOC
SOC was determined in a field experiment at ACRI, Narrabri.
This experiment (Experiment 1) was managed with minimum
tillage and permanent beds, and the stubble from each crop was
incorporated into the topsoil to 10 cm depth.
A further experiment (Experiment 2) was done in pots in a
Nutrition
feature…
Increase soil carbon by managing
stubble
■ By Ian Rochester, Kellie Gordon, CSIRO, Narrabri, NSW,
in brieF…
In most cotton-growing soils, soil organic carbon (SOC)
has declined during the period that these soils have been
cultivated. But changes in the way soil and crop stubbles are
managed can bring about substantial changes in SOC levels.
Importantly, reducing tillage operations (using permanent
beds) and incorporating crop stubble are shown to increase
SOC. Increased SOC is closely linked to improved soil health and
crop production.
controlled temperature environment to investigate the impact of
tillage and stubble incorporation on SOC. Cotton or vetch stubble
was either incorporated into the soil or left on the soil surface;
to prevent soil crusting &
poor germination this season,
looK to apply…
1800 003 244
admin@ultimateagri.com.au www.ultimateagri.com.au 33380
August–September 2012 The Australian Cottongrower — 31