CLOVER MAY have gone out of fashion recently, but when increasing clover content in grass leys can save more than 10 a cow on fertiliser use it must be worth considering.
Great Witley-based Andrew Goodman believes clover is a key tool in maintaining grass growth throughout summer, while also cutting artificial fertiliser inputs.
High artificial fertiliser prices in recent years mean its use has come under the spotlight, with timing, rate and product specification all coming in for scrutiny. But more strategic use of fertiliser may not be the only way to cut nitrogen bills.
The relocation of the 160-cow dairy herd at Walgrave Farm in autumn 2001, gave the Goodmans the chance to reseed large areas of former arable land and reassess the quality of the swards grown on the farm.
“We reseeded with Kingshay mixes at 14kg/acre, 2kg/acre of which was clover. These perennial ryegrass leys were sown with the intention of them being five-year leys,” he says.
“We chose the leys on the basis of research into which grass varieties cows preferred grazing. After all, there is little point sowing 90 acres of grass which cows won”t eat.”
Kingshay research also had a part to play in the clover selection, as trials have assessed clover variety performance in different leys and situations, says Kingshay technical specialist Andrew Butler.
“Trials assessed the compatibility of different clover varieties with different grass varieties and whether grass or clover dominated swards. As a result of this we use three different clover varieties – Aran, Alice and Crusader – in our grass mixes.”
And, while many producers may be fearful of bloat when grazing clover rich pastures, Mr Goodman says he has never experienced any problems. This is because cows are buffer fed while grazing, so they don”t gorge themselves on pasture when turned out to grass.
By using clover in the past four years, Mr Goodman has cut fertiliser use, particularly on silage aftermaths. “We used to apply a lot of fertiliser after first cut and make a late first cut in late May or early June. But by this time clover is normally growing well and fixing plenty of nitrogen, reducing the amount of aftercut fertiliser required.”
Mr Goodman also now avoids applying any fertiliser to pastures after July. “Overall, we have cut back fertiliser purchases from 73.5t in 2001-02 to 60t last year.”
With bagged fertiliser costing 118/t in 2001-02 and about 140/t in 2003-04, Mr Goodman says the reduced use has led to considerable savings on input costs for the herd. “The fertiliser bill for 2003-04 was only 273 less than three years ago. But had we still been using the same amount of fertiliser as we used in 2001-02 it would have cost us 10,290, an increase of 1617.
“So, the total saving, including this increase, is 1890, or more than 10 a cow. With milk prices as they are, this is equivalent to about two days” production at 30 litres a cow.”
The test of reduced reliance on fertiliser, though, is milk yield, something which has continued in the same vein for Mr Goodman. “The rolling average stands at 7800 litres, a level we are reasonably happy with, bearing in mind that we have lost a lot of cows to TB in recent years.
“We are aiming for a rolling average of 8500 litres and in 2003 averaged more than 8800 litres. In 2003 yield from grazed forage averaged 1786 litres a cow, while in 2004 it averaged 1914 litres a cow,” he says.
The real key to maximising the benefit clover can offer is good estab<00AD>lishment, reckons Mr Goodman. “Without a good start it will never yield its full potential. Spring reseeding is best but, with grass leys fitting into the farm”s arable rotation, we normally sow in autumn.
“This is fine in a good year, as we are able to get grass and clover seed sown in August, but last year”s wet harvest caused problems and the ley was late being sown. However, clover still germinated well and sheep in on tack grazed it lightly in January to encourage tillering.”
In addition, nitrogen fixed by clover should improve soil fertility and reduce fertiliser bills for the following arable crop.