Photo showing the typical response to Gibberellic Acid applications (bleaching of leaf but also the extra growth over that of an untreated plot (back).
In the winter of 2016, BioAg agronomists ran a series of trials investigating the optimisation of winter pasture growth and developing a winter-feed wedge.
The trials were conducted in Tasmania, Victoria, South Australia, and New South Wales over predominantly improved pastures (mainly ryegrass and phalaris base).
Dry matter (DM) responses along with quality (protein and metabolisable energy) were measured.
Combinations of Balance & Grow (B&G), Gibberellic Acid (GA) and Nitrogen (N) were tested against a nil treatment.
These products were applied separately, as well as in various combinations, with the idea of evaluating what combination provided the most value in terms of dry matter production and overall feed test.
Comparing the results from each trial site, the most effective combination for producing dry matter was Balance & Grow with GA and N.
This gave an extra 22kg DM growth per day over the treatment period (average of 32 days over the June/July months).
The best individual treatment (over all plots in all states) was a B&G with GA treatment in Northern NSW, which grew over 2 tonnes/ha of extra dry matter over that of the nil treatment.
Both these combinations (B&G/GA/N and B&G/GA) produced statistically significant growth compared to the nil treatment.
All treatments gave a positive result over the nil treatment.
Cost per Hectare
The 3-way mix of B&G, GA and N gave the greater yield, but was also the most costly on a per hectare basis ($42.50) for 22kgDM per day of growth.
The B&G/GA treatment only cost $24.50 per ha to give a very similar result (an additional 20kgDM per day over the period of the trial).
Chart comparing the two most effective treatments in the trial, and their cost per hectare.
Organic Pasture Trials
Another component of this trial was to test similar strategies in organically certified combinations.
There is currently significant interest in organic pastures systems, particularly dairy.
One of the perceived limitations with organic pasture systems is providing enough pasture growth through the winter months.
The alternative is generally supplementary feeding using more expensive organically certified grain or hay.
This part of the trial tested:
• Balance & Grow (Organic) (B&G)
• Gibberellic acid (GA), and
• Fish meal (as an organic source of nitrogen, replacing UAN)
Organic Pasture Trial Results
The results of the organic pasture trial, mirrored the conventional pasture trial, where the combination of the three products (B&G, GA & UAN) provided not only the most dry matter production over the control, but also the greater level of protein, digestible carbohydrates and metabolisable energy.
Whilst the cost of the three products applied as a foliar is more expensive than the conventional alternative (because of the fish meal), it is still a far cheaper option than buying organically certified grain or hay.
2017 Pasture Trials
The trials will be repeated in 2017 to gather more information on the best ways to grow more feed during winter, and towards developing a winter-feed wedge.