Lessons learnt in Canada are enabling new developments to be made in applying nutrients to seed prior to drilling. Emily Padfield investigates.

There are roughly 120 days between planting and harvesting a crop of wheat or canola (rape) in some parts of Canada, and getting the plant growing before the permafrost sets in is a constant challenge. That’s why Canadian farmers routinely apply key fertiliser and nutrients at the time of drilling, usually in the form of a liquid fertiliser.

Yorkshire farmer Robert Rook, who farms at Market Weighton, North Yorkshire, and share farms 2,630ha (6,500 acres) in Regina, Saskatchewan, Canada, already applies P and K when seeding spring wheat, barley, canola and soya, but in a granular form. It was this that made him think that it could be done over here, but with more accuracy using liquid fertilisers and a modified Horsch drill.

And that’s where agronomist Chris Rigley’s company Crop Nutritional Initiative (CNI) comes in. “Growers need to optimise yield and take advantage of the potential held by each crop,” he explains. “In the bag, the genetic potential of wheat can be anything up to as 22t/ha. The UK average is 8t/ha – and the world record is 14t/ha. So somewhere, nearly 12t of potential yield is being lost.”

“Take typically sandy soil types, where manganese deficiency is often a problem. Up to 10% of yield can be lost almost immediately if this is the case.” The idea of applying micronutrients at this stage is to start feeding the crop from day one, adds Mr Rigley, and to limit any of these losses.

Getting the nutrients on to the seed and at the same time into the soil feeds the crop for the first 40 days, he adds. Zinc, magnesium and phosphate are all fundamental to improve rooting in the early stages of seed growth. This optimises yield potential, generates a greater root mass and puts the plant into a better position to “mine” the soil for other major and minor elements, claims Mr Rigley.

Not a new concept

Drilling oilseed rape with adapted subsoilers and tine cultivators has become increasingly popular among farmers over the past five years. Alongside that, band application of fertiliser (like Opico’s NitroJet system) has also been shown to have distinct advantages.

But Mr Rigley is keen to point out that it’s not just nitrogen that can be applied using this method. He has been working with liquid fertiliser specialist Omex to develop a method of applying targeted nutrients as well as nitrogen to seed before it comes into contact with the soil, rather than applying fertiliser in a band after planting.

Adapting the drill

To coat the seed with the nutrients, Mr Rigley has adapted two Horsch Pronto 4 DC drills to deliver the Nutri-Feeder system, one owned by Mr Rook and one by local drilling contractor, James Fenwick.

“We’ve fitted a tank with a simple, high capacity pump and a Garmin GPS unit to regulate the amount of liquid distributed to each coulter,” he explains. Two 14-branch manifolds strapped to the back of the grain hopper take the liquid to each individual coulter.

High-pressure air jets are used to transport the liquid, explains Mr Rigley. “The 28 coulters each have a nozzle positioned further up the seed tube that, as the seed passes the jet, applies liquid fertiliser.

Mr Rigley is confident that the system can be fitted to any type of drill, even non-pneumatic ones.

This year, 10% of drill contractor Mr Fenwick’s barley has been drilled using the system. “It’s true that the benefits have been enhanced by the dry conditions at the start of the growing season. Quite by accident, the difference became clear when looking at where one nozzle had become blocked and the establishment rates between seed treated and untreated was tangible.”

The cost of adapting the first drills has worked out at about £3,500, which includes the tank, manifolds, pipework, jets and GPS unit.