Wednesday, 18 March 2015 00:00

N. question hard to answer

Written by 

Is it worth applying nitrogen fertiliser to speed pasture recovery post drought?

 A Beef + Lamb New Zealand field day in North Otago, earlier this month, heard it’s a hard question to answer.

“The issue is how long has it been dry and whether there’s enough nitrogen [in the ground] to get that initial response,” AgResearch’s David Stephens said.

If there is enough N in the ground, grass will grow 450kgDM/ha from 15mm of rain, a 30:1 response. If there isn’t, the growth from that moisture may be halved.

Fellow speaker Graham Kerr said remember nitrogen is simply a growth multiplier. “If you’re growing zero, you’ll still get zero. If you’re growing a bit, you’ll get a bit more. If it’s growing well, then you’ll get a lot more.”

Whether the response to fertiliser would be economic would “depend on how desperate [for feed] you are,” he added.

“It’s a tricky one because you don’t know how much is going to be released from the soil. It really is quite variable. In general if you’re desperate for feed you put it on because by the time you see it’s needed it’s too late.”

If nitrogen fertiliser is applied it’s imperative to wait at least three weeks, preferably four, for pasture to use it. Grazing sooner risks nitrate poisoning and curtailing the plant’s growth response.


More like this

Getting smarter at growing grass

In his third season, sharemilker and Ravensdown shareholder James Barbour takes us through the farm’s approach to nutrient management.

Rural water faces nitrate risk

Farming families across Canterbury are the ones at most risk of the health effects of nitrates in their drinking water, says Canterbury medical officer of health Alistair Humphrey.

Taking the p*ss out of leaching

Having seen Spikey from Pastoral Robotics at the 2017 National Fieldays, we recently caught up with a unit that had completed two seasons on a dairy farm a short distance from Rotorua.


Get ready for the ‘now’ norm

Get prepared for a ‘Now Normal’ future, says Ian Proudfoot – Global Head of Agribusiness for KPMG – discussing the likely effects of COVID-19 in the months to come.


Northland farmers count the costs

Northland farmers are starting to count the cost of one of the most severe droughts to hit the region as the cost of feed and lower prices for stock are the order of the day.

Times will get better for deer sector

While the deer industry faces several challenges in the short term, there will be a strong rebound in New Zealand venison sales once global demand recovers.

» The RNG Weather Report

» Latest Print Issues Online

The Hound

Dirty water

The Hound understands that Federated Farmers has been cut out of the information loop, for the past year, on the…

Who’s paying?

Your canine crusader noticed a full-page ad recently run in a farming paper calling on meat companies SFF and Alliance…

» Connect with Rural News

» eNewsletter

Subscribe to our weekly newsletter

Popular Reads