Calibration and product choice the key to fertiliser success

Correct set-up and calibration of spreaders can make a significant difference to the effectiveness of fertiliser applications and hence their value to grassland, farmers are being reminded as spring approaches.

A well-calibrated spreader can ensure a uniform application to grassland and maximum benefit from the application. “Good general maintenance is the basic ‘must-have’, such as replacing any worn parts and keeping it properly lubricated,” says Rob Foxall, manager of spreader testing company SCS. “Now’s the time to start thinking about servicing the spreader and doing a tray test to check the spread pattern.

“But calibration isn’t just about getting the machine in good working order, it is also matching the set-up to the type of fertiliser being used,” he continues. Differences in size, weight and shape of the fertiliser will affect how it travels through the air. Strength is also important, as weak granules break up and don’t have the velocity to make it to the full width of the spread.

“Different types of fertiliser spread in different ways, so consistency is very important if you are to get the same spread in all your fields. Quality brands such as Nitram are manufactured to precise tolerances, giving very predictable behaviour in the spreader,” notes Mr Foxall. “The other thing to remember is that blends of two or more nutrients don't always give even distribution of each nutrient across the spread pattern.

“This is because the product with N may have different physical properties to that containing the P and K so each nutrient spreads in a different way. The best way to minimise the risk of this happening is to use compound fertilisers where each granule contains a bit of each nutrient" In recent years, many grassland farmers have started using GPS and bigger spreaders, often delivering up to 24m of width.


At this distance, product quality becomes even more important. “When spreading to 24m, the physical impact on the fertiliser is quite high,” explains GrowHow agronomist Allison Grundy, “so you need a tough product that won’t be damaged by the spreader. “However, irrespective of the size of your spreader, there is an advantage in using products with reliable characteristics. This means you can be confident in the spreader’s consistent set-up. Nitram and all GrowHow products are manufactured to be consistent within and between batches, which promises consistent performance every time.”