GrowHow is investigating the optimum timing and amount of N two-row and six-row winter barley varieties require, the firm’s Allison Grundy said.
Advice in RB209 suggested that N fertiliser should be applied during early stem extension if the requirement was less than a 100kg/ha, or it was more than that, 40kg/ha should be applied earlier during late February, she said.
Barley N recommendations may need adjusting, according to GrowHow’s Allison Grundy
But GrowHow believed more should be applied earlier than stem extension. “The barley growth guide says optimising ear numbers and tiller survival is important to maximising yield. So what do we do? Let the crop go yellow before applying N, and lose tillers.”
Applying more N earlier should optimise tiller production and survival and increase yields, she said.
Earlier N in trials this year has at least produced more ears – 20% more from an 80kg/ha application. “But there is a balancing act to keeping it standing,” she noted.