Grain growers can access a range of online tools and resources to help navigate the season and optimise their crop potential in what, for many, has been a challenging growing season.
The WA Department of Primary Industries and Regional Development has harnessed many of these decision making aids on its dedicated 2017 Growing Season Resources webpage.
There is great variability in crop potential across the grainbelt this season, ranging from well below average rainfall in the north east, to average and below in the central and Great Southern areas, while conditions on the south coast are more favourable.
Senior development officer Jeremy Lemon said the Department’s website included resources to assist growers currently wrestling with whether or not to apply a top up nitrogen fertiliser and how much.
“There are many tools available that will help growers to assess their situation objectively and make a confident decision based on the available facts,” he said.
Mr Lemon said many factors affected crop yield potential so it was important to assess paddocks individually before making fertiliser decisions.
“To make a confident decision in investing in top up nitrogen, growers need to consider soil nitrogen availability, yield potential, forecast rainfall, soil moisture, how much fertiliser has already gone in, costs and grain prices,” he said.
“Paddocks with loams and duplex soils and heavy summer rain may not need a top up, as there is still mineralised nitrogen available, while mineral nitrogen may have leached in sandy soils in wet areas, so it will be important to compare the yield potential with the return on investment.
“A rough ‘rule of thumb’ is to use 40 kilograms of nitrogen per tonne of grain for wheat when making calculations.”
Department tools to assist this calculation include the Statistical Seasonal Forecasting system, yield potential tool, rainfall to date tool, soil water tool, in conjunction with other commercial tools, like the N broadacre – nitrogen calculator app and the Bureau of Meteorology’s website.
Mr Lemon said with recent rainfall, growers with crops at the tillering stage could be deliberating over how long they can delay treatments, waiting for a more definite direction for the season.
“Field research shows that additional nitrogen can be delayed on cereals until the beginning of stem elongation and early flowering for canola. However, the benefit of nitrogen fertiliser depends on the yield achieved, determined by the finish to the season,” he said.
The Department’s Statistical Seasonal Forecasting system has also been recently updated for July 2017, showing a continued drier than normal outlook for July 2017 to September 2017, although the eastern grainbelt has a more neutral outlook.
While this may suggest better rainfall, the forecast model has lower predictive skill for that region at that time. The rainfall outlook from the Bureau of Meteorology is also indicating drier than normal conditions are more likely for this period.
Meanwhile, the Department’s eConnected Grainbelt project has been working with grower groups to examine how best to use digital technology to enhance decision making.
Source: WA DPIRD