Sitting alongside the National Sprayer Testing Scheme, the National Spreader Testing Scheme takes on board economic, environmental and compliance issues to deliver this national standard for fertiliser spreader tests. The spreader testing protocol ensures all spreaders; disc, boom and pendulum, are tested to the same exacting standard.
While the immediate impact of inaccurate spreading is financial, it can also affect conservation field margins and lead to contamination of water courses.
According to Defra’s fertiliser manual (RB209), fertiliser spreaders should be regularly maintained and serviced, replacing worn parts as necessary. To check uniformity of spread pattern, trays should be used to produce a coefficient of variation across the full width of spread.
A coefficient of variation above 20% will lead to visible striping in crops. And as this figure increases from 20-30%, crop yields in wheat and oilseed rape for example, are likely to be reduced. Even if there is no visible stripes in the crop, there is no guarantee that fertiliser is being evenly distributed cross the desired working width.
The National Spreader Testing Scheme has been created to promote efficient use of fertilisers and to help growers achieve better yields. Additional benefits of annual testing include; the meeting of cross compliance and NVZ regulation, and ultimately delivering peace of mind that fertiliser application is correct.