Monday, 20 April 2015 10:13

More tools in the box

Written by 
Ants Roberts, Ravensdown. Ants Roberts, Ravensdown.

There's been noise in the market recently about urea coatings that can reduce volatilisation -– the process where nitrogen is lost to the atmosphere rather than available to the plant. 

The trouble with all this averaging and aggregating up is that farmers may think they need a urea coating when their farm conditions would actually make it unnecessary. 

Basically, there is more than one way to skin the N-loss cat. 

With the current state of dairy payouts, everyone wants the same thing: the amount of N you get to keep for your plants relative to your conditions in your part of the country. 

Under all except the most extreme conditions, e.g. hot, dry and windy and applying high rates of N, the losses in pastoral farming are expected to average 10-15% (or less) of the N applied as urea. Any claim of coated products reducing N loss by, say, 50% can be misleading because that does not mean half of the total applied nitrogen. Rather, the claims mean half of the 10-15% which of course equals 5-7.5%. 

How much N does this mean is being saved for plant growth?  If you apply 65kg urea/ha (30kg N/ha) and lose 10% to volatilisation, you are losing 3kg N/ha and with the urea coating you will reduce this to 1.5kg N/ha (at 50% reduction of volatilisation). 

At times, the premium for a coated product can be 8-10% more than standard urea.  

As a famous psychologist once said: “When the only tool you have is a hammer, every problem looks like a nail.” If a fertiliser company with a urea coating tells you it’s the only solution to volatilisation, they should also inform you of the several other ways volatilisation can be tackled. 

There are at least five other simple steps you could consider to help reduce volatilisation: 

Apply lower rates each application e.g. 30-50kg N/ha (volatilisation rates increase with higher rates of N application)

Apply when it’s raining or about to rain or use at least 10mm of irrigation straight after application

Apply to pastures with some leaf cover

Avoid hot, dry and windy conditions

If applying to soil, incorporate so it is just below the surface. 

• Ants Roberts is chief scientific officer at Ravensdown.

More like this

Featured

 

Wool group raises $500k

A new group established to revise the fortunes of New Zealand’s struggling strong wool sector says it has already raised more than $500,000 and is starting to roll out its work programme.

Bring on the blueberries!

While Hew Dalrymple was beginning his journey with broccoli, brother Roger became involved in a state-of-the-art blueberry growing operation, which sees the fruit grown in hydroponic pots in huge tunnel houses.

National

Expat workers ready for NZ

Dairy industry recruitment company Rural People Limited is seeing a huge increase in overseas interest to fill New Zealand farming…

Machinery & Products

Kubota ROPS tractors here

Kubota New Zealand product specialist Shaun Monteith says Rollover Protective Structure (ROPS) tractors make up 30% of all tractors in…

» The RNG Weather Report

» Latest Print Issues Online

Milking It

Dung paint

India now has its own cow dung paint, a world-first. 

Fresh for 60 days

A Queensland-based company is set to release its own production of milk this year that stays fresh for at least…

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter