Nitrogen is key in making the most of muck
Allaboutfeed.net, February 11th
Persuading farmers to regard muck and similar materials as fertiliser rather than waste is getting easier, as they look to slash soaring nutrient input costs
The main reason is the rocketing price of manufactured fertiliser, explains Brian Chambers, ADAS head of soils and nutrients.
- In the past 10 years the prices of manufactured N, P and K fertilisers have all just about tripled. Today nitrogen is about 90p/kg - only a few years ago it was only about 30p/kg. Clearly by using organic sources growers can reduce production costs.
Many farms have access to manures that cost comparatively small sums and attract little more than storage and application charges, Prof Chambers points out.
Another key reason for growers' greater interest is improved technology allowing them to assess the nutrient content of manures more quickly and apply them more precisely, he adds.
There are plenty of fertiliser substitutes.
- Farmyard manure and slurries are still the main sources, but the new kid on the block is digestate. We're now seeing significant volumes coming through, and annual output could rise to 5m tonnes.
Solid fertiliser substitutes, especially composts and sewage sludge cakes, have extra long-term value in that they help raise soil organic matter levels, adds Prof Chambers. As manufactured fertiliser prices have increased so has the value of organic materials, and suppliers have raised their prices in line, notes Hutchinsons' Rob Jewers.
As well as contributing nutrients, they improve the soil's structure and water retention and benefit the organisms living within it, he adds. Ideally, to minimise nutrient losses, they should be applied in early spring.