Increase nitrogen use on all malting barleys
Increase nitrogen use on all malting barleys
By Louise Impey
BE prepared to use up to 20% more nitrogen on spring barleys than you would have done three to four years ago, advises Simon Phillips of New Farm Crops.
Higher yielding varieties and greater demand for lager malts are two reasons why inputs can safely be increased, he suggests.
"In England, most grain needed by maltsters has to have nitrogen of 1.65-1.85%. In Scotland, its different. The distilling market wants grain at 1.55% and brewers slightly higher at 1.65%."
Higher yielding varieties, such as Optic, also dilute grain nitrogen, so growers are unlikely to push levels too high by boosting fertiliser N.
"The old standard for nitrogen of 100kg/ha should be increased," says Mr Phillips. "Growers can go as high as 150kg/ha without jeopardising crop quality."
It is important to remember that the total applied should reflect residual levels in the soil. "Its a case of knowing your land. Tests should be done where manures are used or there are vegetable crops in the rotation, so nitrogen is matched to soil supply and crop requirement."
NFC trials over the past two years on Optic, Cellar and Tavern compared nitrogen rates. "Going to 150kg/ha gave us a grain N of 1.7%. At 140kg/ha, it was 1.68%."
Timing
Timing of nitrogen should depend on drilling date, says Mr Phillips. "At a normal date of end of February or early March, half the nitrogen should go on at the 1-1.5 leaf stage and the other half ten days later."
Drilling after Mar 10 merits slight adjustment. "Put half on immediately after drilling and the rest at the 1.5-2 leaf stage. The crop grows very quickly as it gets later."
If drilling is delayed until mid-April, N rates should be revised downwards. "Use 20-30kg/ha less. Crops are less responsive and the risk that grain levels are too high is greater."
Winter barley
More nitrogen should also be applied to winter crops for malting, believes Farmacys Jonathan French. "Growers have to adopt a new approach. They should aim for a grain N of 1.7%."
He suggests 120-130kg/ha of N will suit most crops. "Recent trials show you can get higher yields and still have appropriate grain quality."
However, this seasons crops have made good use of soil reserves and are very lush. "There will be no rush to put nitrogen on. Where you dont know the field history, carry out a soil test or get one done to assess residual N. Otherwise, RB209 will give good figures to work with."
All the N should be on by first node stage (GS31), he advises. "So work back from there. Most crops will get a two-way split, with 40kg/ha applied between GS21-29, and the rest aimed at GS30."
A three-way split may be better if leaching is a particular concern.
First dressing may be at the end of February this year. "Crops have raced away, so get out in the field and look at their development."
Most malting barleys will need sulphur, he adds. "So make sure it goes on in the spring, in a form available to the plant." *
NFORMALTINGBARLEY
1 Amount Winter & spring crops need 20% more N than in past.
2 Varieties New, higher yielding types respond well to more N.
3 Malt type Lager dominates, so grain N 1.65-1.85%.
4 Soil supply Previous cropping important, use RB209 or test soil.
5 Spring barley Apply up to 150kg/ha of N.
6 Sowing date Use 20-30kg/ha less if drilling delayed.
7 Timing For crops drilled before Mar 10, use half N at 1-1.5 leaf stage with rest 10 days later. For crops sown after Mar 10, apply half immediately after drilling with rest at 1.5-2 leaf stage.
8 Winter barley 120-130kg/ha suits most crops.
9 Timing Get all N on by GS31, using two or three-way split.
10 Sulphur Most crops at deficiency risk. Apply S in spring.