Bionew Trial on Buffel Grass in Central Queensland
Scott Stevens – Farming and Beyond Pty Ltd
American buffel grass is the dominant sub-tropical pasture species originally introduced into central Queensland
in the late 1960's. Initially animal performance [weight gain] was very high on this pasture but due to soil fertility
decline and grazing management, weight gains have and continue to decrease. To counteract the 'buffel rundown' practices such as spreading superphosphate were trialled with immediate but short-lived success to
increase cattle performance. Some producers introduced leucaena, a native legume tree form Central America,
in rows to provide an alternate protein source. While this practice has been very successful boosting animal liveweight gains, not all pastures can be planted to leucaena because of soil type, rainfall and low lying areas prone
to frosts.
A trial commence din February 2011 to investigate ways of improving the nutrient density and brix levels of
buffel grass. Pasture tissue tests and brix analysis indicate that buffel grass has several nutrient deficiencies and
very low brix levels which could be directly related to lower animal production. To correct plant nutrient
deficiencies and increase Brix levels, the trial is investigating foliar products from BioNEW, an emerging company
what specialises in chelated, fermented biological innoculums for application in broad-acre cropping and grazing
systems.
Figure 1: Buffel grass actively growing four weeks following the original
application of BioNEW products.
Two products were chosen for the trial, Feed & Boost and Maaxis. Feed & Boost is designed to increase sugar
production [i.e. brix levels] in plants through the actions of specific bacteria enhanced with naturally occurring
minerals.
Maaxis is a more concentrated product with higher levels of macro and trace elements formulated for crops or
pastures with higher nutrient demands.
The trial consisted of the following treatments:
1. Feed & Boost @ 5L/ha [recommended rate] in 150L water.
2. Maaxis @ 5L/ha [recommended rate] in 150L of water.
3. Feed & Boost @ 5L with 5kg/ha Liquid N in 150L of water.
4. Maaxis @ 5L/ha with 5kg/ha liquid N in 150L water.
5. Control.
The products were applied on the 24th February to actively growing buffel grass in early Phase 2. In-field
monitoring since the commencement of the trial has shown little change in the brix levels for each treatment.
An unexpected benefit though has been the apparent increase in water holding capacity of Treatment No 3 – the
Feed & Boost combined with Liquid N. Using a standard penetrometer, testing of soil resistance four weeks after
the initial application showed this treatment had increased water holding capacity to 30cm depth when
compared with the other treatments. Soil resistance levels were greater than 900psi at the soil surface for all
treatments except the Feed & Boost with Liquid N which averaged 600psi for the top 10cm and then 700psi to
30cm depth.
Further investigations of the thatch layer on top of the soil surface revealed that cellulose digesting fungi had
colonised the decaying buffel grass. The thatch layer was up to 10cm in places and with adequate soil moisture,
had provided ideal conditions for the fungi to colonise the entire treatment [Figure 2.] While the thatch layer was
similar across all treatments, fungal frequency and size of colonised sites were appreciably smaller when
compared to the Feed & Boost with Liquid N
treatment.
While the trial has not produced the outcomes as
originally intended, the decrease in soil resistance
and associated increase in soils water capacity has
derived other unintended outcomes. These
improvements are expected to increase the longevity
of plant activity as soil moisture levels decline and
should provide a habitat for soil macro- and microorganisms that will deliver further benefits to the
health of buffel grass.
Conclusion:
The trial will continue to review the use of other
mineral elements in combination with BioNEW
products in order to increase the nutrient density
and brix levels of buffel grass in central Queensland.
Figure 3: Close-up of cellulose digesting fungi [white
filaments] attached to decaying buffel grass.
Figure 2: Cellulose digesting fungi attached to decaying buffel
grass on the soil surface.