Dairy farmers could significantly boost grass yields by paying closer attention to detail when applying slurry this spring.
With the closed spreading period in Nitrate Vulnerable Zones now over, farmers will be keen to get on spreading manure as soon as they get a weather window, says Professor Brian Chambers, head of soils and nutrients at ADAS. And by adopting a more scientific approach to manure use, producers could dramatically improve both grass yields and quality.
“The first thing to do is to get your slurry analysed, so you know what level of nutrients it contains,” says Prof Chambers. “It only costs about £30 to do – and given the price of fertiliser now, manure is a valuable resource. You wouldn’t apply a bag of fertiliser without knowing what’s in it.” Although the RB209 guidelines provide reasonable averages, every farm’s manure will be different; and matching nutrient application to soil and crop requirements has a direct impact on both input costs and productivity.
Prof Chambers is convinced that most farmers can improve profitability through better manure management, and will be explaining how, with the aid of case study farms and the latest research results, at the Grassland & Muck Event in May. “Spring application increases nitrogen uptake compared to autumn application, particularly in wet seasons and on sandy soils, meaning better grass growth and less leaching,” he says.
But the method of application is similarly important. “Rather than using a broadcast spreader, consider using a trailing shoe; it reduces nitrogen losses and has the major benefit of cleaner grass, meaning cattle can graze sooner after application.”
Many of the farms that Prof Chambers works with have invested in umbilical spreading systems, eliminating the need for heavy spreading equipment. “That’s a significant advantage, given the difficult spreading conditions we’ve been having in recent seasons.” Of course, changing equipment or infrastructure is expensive, so farmers should consider using contractors or sharing machinery with neighbours to reduce costs. They may also look at covering their slurry store to reduce rainwater inputs and nutrient losses, and should always prevent clean water going into the slurry tank.
Visitors to the event will be able to see the full range of muck application equipment, to find the best solution for their farm. “The important thing to remember is that it’s absolutely in your own interest to make every kilogram of manure nutrients count,” says Prof Chambers. “Most farmers know that spreading slurry will raise soil phosphate and potash indices, but recent research has shown that it also makes a valuable sulphur contribution. A lot of high output grass farmers are not adding enough sulphur, particularly for second and third silage cuts; they put the yellowing grass down to nitrogen deficiency, when in fact it is likely to be sulphur.”
Prof Chambers will also be showing visitors at the event how to use the updated MANNER-NPK software to compare different manure management techniques for maximum productivity. “The software used to only cover nitrogen management – now it includes phosphate and potash, and gives everything a financial value. Ultimately, that is what better manure management is all about – improving the bottom line.”
