Farm Table says:
What is the problem?
The first aim was to examine the effectiveness of coating wheat seeds with surfactants and hydro-absorbers to improve crop establishment on water repellent soils.
The second aim was to examine the effectiveness of coating MAP fertiliser granules with elemental S compared to applying a sulphate fertiliser source (ammonium sulphate).
What did the research involve?
Seed coatings – Seeds were coated using a 14-inch rotary seed coater (BraceWorks, Canada). Polyvinyl alcohol (Selvol-205) glue was the binding agent, and lime and talc powder were the drying agents. The rates used were 0.1%, 0.2% and 0.4% of a surfactant and 1%, 2% and 4% Stockosorb 660® per seed weight.
Fertiliser granule coatings – The source fertilisers used in the experiment were triple super phosphate (TSP), mono ammonium phosphate with trace elements Zn and Cu (MAPSZC®), ammonium sulphate (AS) and the Summit
The experiment used two forms sulphur (sulphate and elemental S). Sulphur applied as coated
elemental S and sulphate applied in the form of ammonium sulphate were applied at the same S rates
to enable direct comparison between S sources. Seeding of the wheat variety Justica occurred on 28
May, 2016. Plot harvest to derive grain yield (t/ha) occurred on the 25 November, 2016.
What were the key findings?
- Coating agricultural inputs onto seed or fertiliser granules can potentially increase efficiency (handling and/or agronomic) of that agricultural input.
- Coating wheat seed with Stockosorb 660® hydro-absorber and a surfactant may reduce the impact of water repellence and improve handling efficiency. However, in trials conducted in 2016 we were not able to illustrate an improvement in agronomic efficiency due to a wet autumn reducing the occurrence of water repellence at the experimental site.
- Coating fertiliser granules with elemental S may improve the agronomic performance and handling efficiency of applying S fertiliser. However, in trials conducted in 2016 we were not able to demonstrate an improvement in agronomic efficiency due to the high soil S status for the test crop used (wheat) and low S leaching intensity due to seasonal conditions and soil type.
They have developed techniques for coating hydro-absorber and surfactant onto seed and elemental S
onto fertiliser granules.
These techniques increase the handling efficiency of applying these agricultural inputs.
However, seasonal conditions in 2016 (wet autumn) reduced the occurrence of water repellency while relatively dry June and July reduced the occurrence of S deficiency. Under these seasonal conditions, we were not able to show a benefit of coating Stockosorb 660® and surfactant to wheat seed and elemental S to fertiliser granules. Further evaluation will be undertaken in growth cabinets and in the field in 2017.