|Authors: ||A.M. Abobaker, S.A. Bound, N. Swarts, D.C. Close|
|Keywords: ||inoculation, Hoagland’s solution, organic additives, chlorophyll content|
Biological farming methods are becoming more widespread as many farmers move towards the application of composts, bio-fertilisers and other organic additives.
To assess the impact of coal-based humus and effective microbes on plant growth, two trials were undertaken on sunflower (Helianthus annus L., 'Dwarf Sunsation'). Two-week-old seedlings were planted into 16-cm diameter pots containing a basic potting mix plus Ferbon®, a lignite-based soil conditioner, at 0, 0.3 and 0.6 g pot-1 (equivalent to 0, 150 and 300 kg ha-1, respectively) in Trial 1, and 0 or 0.9 g Ferbon® (equivalent to 450 kg ha-1) in Trial 2. After planting, pots were placed on glasshouse benches arranged in a randomised block design with six replicates per treatment for both experiments.
Activated effective microbes (EM-1, Vital Resource Management Pty Ltd.) were applied as a soil drench at 15 L ha-1 to half the pots after planting in Trial 1, and 0, 15 or 30 L ha-1 to pots in Trial 2. Pots were fertilised at weekly intervals with HoaglandRSQUOs solution at 0, 50 and 100% concentration in Trial 1, or 0 and 100% in Trial 2. The label rate of 15 L ha-1 EM increased the number of nodes and stem height.
Ferbon® had no effect on node numbers, but did increase stem height (Trial 1). The full rate of fertiliser resulted in increased stem height during the first 6 weeks of growth, but by week 9, the 50% fertiliser rate produced the same results as the full rate.
Plants treated with EM displayed reduced leaf chlorophyll content compared with untreated plants.
This reduction may be a function of increased biomass, evidenced by increase in plant height and stem diameter, deploying nitrogen.
Ferbon® had no effect on chlorophyll content.
Applications of both EM and Ferbon® resulted in earlier flowering.
These results demonstrate that with the availability of adequate accessible nutrients, both effective microbes and lignite-based humates such as Ferbon® have the potential to increase plant productivity.
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