Some of you were lucky enough to get some relief with the rainfall events in late June and throughout July, but for others it is shaping up to be a year to forget. To get the best return on investment in such a tough year as 2017, it is important to be mindful about improving efficiency and effectiveness of post-emergent N applications on crops that are worth topping up.

Before making any decisions about nitrogen applications this year please consider the following points.

Most of the wheatbelt is currently tracking at a decile one for rainfall. Even if your area receives decile nine rainfalls for the remainder of the year, it will still only finish with decile four rainfalls. Actual local rainfall to date vs. ‘realistic’ predicted rainfall for the remainder of the growing season will provide a good indication towards yield potential.

The date of emergence also has a considerable impact on a crops final yield, with DAFWA trials between 2008 and 2013 showing that Mace wheat lost 28kg/ha/day of yield potential for any wheat crops emerging after the end of May. For example; any wheat crop that emerged on the 20th of June may have lost up to 0.56t/ha of yield potential.  This reduction in yield potential will need to be considered when calculating in-season nutrition requirements.

Heavy soil types and non-wetting soils have germinated poorly this year, resulting in reduced plants/ tillers per m2, in turn lowering yield potential and immediate requirement for post-emergent nitrogen.

Due to the lack of heavy rains in some areas, most of the nutrients applied at seeding and mineralised nitrogen from summer will still be accessible to the plant roots. This also means that post-emergent applications of nitrogen may be reduced or may not be required due to the reduced leaching experienced. Sulphur requirements should also be considered.

A challenging season provides an excellent opportunity to take advantage of plant testing your crop. Plant testing is the most accurate way to determine exactly what nutrients the plant has accessed this season and any ongoing in-season requirements. Given how the season is unfolding, you should be looking to use a product that provides you with both accuracy and flexibility. Flexi-N is a product that is especially effective in a drier year such as this one.

Why choose Flexi-N?

Application width

Wider swath widths from a boom application means a reduction in paddock traffic and therefore less crop damage. Typical boomspray widths are 30-36m, while most spreaders can only accurately spread 18-24m, this will depend on product source, elevations & weather. CSBP has a number of spreader accuracy tray kits available, so if you would like to test the spread pattern and accuracy of your spreader please contact your local area manager.

Flexi-N top ups
Fig 1. Self propelled boom applying Flexi-N before unexpected rainfall

Ease of application

Flexi-N can be effectively applied in windy conditions or before/during rainfall events with the use of streamer nozzles, also allowing you to travel at higher speeds to increase the amount of hectares covered per hour. It is important to note that when using streamer nozzles a pesticide chemical is not mixed together.

Application costs

Flexi-N is compatible with most Ag Chem products, therefore has the ability to be applied with a post emergent spray. Combining with a required chemical spray will avoid extra application costs by reducing time, labour, wheel tracking and maintenance.

Application accuracy

Application of Flexi-N can even be accurate at lower rates, such as 20L/ha, due to the number of individual nozzles across the bar. Spreaders in comparison rely on the product being thrown from two centrally located spinners, resulting in attempts to spread below 40kg/ha very difficult to maintain accuracy. 

Fig 2. Shows stripping caused by inaccurate spreading.

Nitrogen availability to the plant

Flexi-N provides a sustained release of nitrogen to the plant and contains approximately 50% urea, 25% nitrate and 25% ammonia. The nitrate component is immediately available to the plant after it is applied. Urea on the other hand requires approximately 10-14 days following a rainfall event before it starts to become available to the plant, without rainfall the urea granule sitting on top of the soil is highly susceptible to volatilisation.


The biggest advantage of Flexi-N is that if it is not needed in the current season it can be carried over into the following season. Flexi-N can be stored in specialised storage tanks located around the property without imposing any deterioration of product quality, while urea has to be stored in a shed taking up valuable space and potentially breaking down in quality before next years season.  

Take Home Messages

  • Determine a realistic yield potential
  • Plant test
  • Recalibrate in-season nutrient requirements for your estimated yield potential based on plant and soil test data.
  • 4R principles: Apply the Right product at the Right rate at the Right time to the Right place
  • If you are applying granules ensure your spreader is correctly calibrated

If you have any further questions, queries or would like assistance in calibrating a spreader, working out yield potential or recalculating in season nutrition requirements please do not hesitate to contact your local CSBP Area Manager.

Matthew Tropiano
By Matthew Tropiano
- Senior Account Manager
Matt grew up on a family farm south of Mullewa, and completed a Bachelor of Agribusiness at Curtin University, before joining CSBP in late 2016.

Having been involved in the agricultural industry his whole life, and enjoying all aspects, Matt is most passionate about increasing the efficiency of producers to improve the sustainability of the industry. 

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