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Country Wide March 2018 

Page 29

Fert and forget

Andrew Swallow

Northland-based independent fertiliser consultant Russell Plank of Nutralink says about six of his clients used Smartfert this summer, though he recommended it to many more.

  “I prefer it for maize silage because they can shut the gate and forget about it. They put it on with the P and K by truck before sowing.”

  Smartfert-treated crops “always seem a lot greener and look better” than those requiring post-emergence side-dressing, especially in wet years when it’s proved hard to get on paddocks, he says.

  “Ringing a chopper up to get the nitrogen on isn’t cheap.”

  There’s also a place for it on grass, he says, either in autumn where it’s likely parts of a paddock will get too wet to travel going into winter, or in spring where lack of moisture may mean the nitrogen needs to be retained on the paddock until rain arrives.

  “The problem is, it’s not cheap. That’s

its biggest downfall. If it was less than $1000/tonne that would certainly open it up.”

  Mathew Martelli, who milks 380 cows in partnership with his parents at Reporoa, says the price “takes a bit of getting your head round” but after using Smartfert for five years on chicory, he’s used it on maize as well this year and is considering using it strategically for grass too.

  “It’s slow release so instead of urea, some of which disappears as soon as it rains because the plant can’t absorb all the nitrogen, it stays there.”

  With chicory, the general practice is to apply a bit more nitrogen after every grazing but instead of going back five or six times with Smartfert they’ve needed just one pass at planting, he says.

  What that’s saving in application costs he hasn’t calculated but he says it’s worked so well that they’ve tried it for maize too this year.

  “Most people helicopter on the nitrogen two months after sowing around

here because the crop’s too tall and that’s not cheap either.”

  On grass he’s considering a strategic autumn application to keep growth going over winter and ensure there’s some nitrogen there in the spring.

  If you were to use Smartfert in spring, Martelli says you’d have to allow for the time lag in response compared to untreated urea or use a 50/50 blend with SustaiN to get an immediate response with the Smartfert kicking in a few weeks later. 

  *The 2015 and 2017 NZGA papers on Smartfert, both by Edmeades and McBride, are available free online at www.


POTASH AND NZ PRODUCTION NEXT?    Smith says he is trialling a coated potash product, but it will be a year or more before there are results available, and those will only be proof of concept with field trials to follow.

  He’s also looking into establishing a fertiliser coating plant in New Zealand instead of importing from Malaysia. Coating here would facilitate offering a range of the biopolymer-coated products to suit different uses and reduce order lead times and stock holding requirements.       

  “This year at one point we ran out of stock in the North Island,” he says.

  As the quantity of Smartfert used nationally increases, it should be possible to reduce prices, AgKnowledge’s Doug Edmeades says, who has conducted and/ or analysed much of the trial work but stresses he has no pecuniary interest in Smartfert’s success.

  “Longer-term my interest is in the number of coats and the ability to control the rate of nutrient release to match uptake of a range of plants. That’s really where this is heading.”

Key points

Controlled release rationale.

• Nutrients released to meet plant         demand.

• Release rate determined by              coating, temperature and moisture.

• Established technology in                   horticulture.

• Smartfert first to target broadacre       farming.

• Biopolymer coat extends urea             nitrogen release to 90-100 days.

• More coating and nutrient                   combinations likely in future.

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