Grazing of Wheat for Extra Profit

September 2006
Sowing wheat in early autumn at higher than normal densities, and grazing it late August /early September before the seed head is at grazing height, gives a valuable forage crop at a time when feed is scarce.

Trials funded by MAF-SFF and FAR have shown how and when to do it, and that there is both environmental and economic benefits. A booklet has just been produced for growers. (For a copy of the booklet contact the FAR office at Lincoln, 03 3256353)

In the mid-1900s, many New Zealand farmers grazed cereal grain crops, but the knowledge of how best to graze wheat has largely been lost. Over the past 20 years, the move to earlier sowings and use of new cultivars has led to a marked increase in grain yields. With such high potential yields, grazing was discounted as being detrimental to yield.

A few trials some years ago showed that there was a real opportunity for New Zealand mixed cropping farmers to graze wheat crops in early spring. This would potentially provide feed and extra income without compromising the yield or quality of the grain crop. However, most growers were concerned that grazing would damage the growing point of the wheat plant, reducing ear numbers and/or photosynthetic area, and hence yield. This project has provided the information on how to graze the wheat crop without grain yield loss.

Results of nine field trials over the three seasons showed that:

grazing the autumn so on wheat grain crop at GS30 --31(ear at 1cm to first node -- late August/early September) gives sufficient forage for grazing without loss of grain yield.

In lightweight gain trial, wheat produced later lamb lightweight gain (300g per head per day) than annual ryegrass (249g per head per day) or Triticale (216g per head per day) over a 30 day period

lightweight gain resulting from grazing wheat was economically desirable, providing $110 per hectare additional income, equivalent to growing a further 3.12 tonnes per hectare of grain.

When grazing March and April so on wheat, a plant population of 250 plants per metre squared gave improved dry matter production and increased grain yields compared with more conventional plant population is for grain crops sown at the same time.

The application of autumn nitrogen gave so significant benefits to forage yield at GS30--31.

Of six autumn wheat cultivars, wheat cv. Equinox gave the best combination of both forage yield at GS31, and grain yield.

The financial benefits include:

"Free" grazing on wheat grain crops at a time when pasture feed is scarce. This has a value of between $150 and $250 per hectare.

Excellent lamb growth rates on wheat -- in fact better than Tama ryegrass or Triticale.

Less need for fungicides, herbicides and straw shorteners. Grazing may remove diseased leaves and weeds and shorten the crop straw, reducing the risk of lodging.

Cost savings of around $100 per hectare are possible.

Diversification

There are also environmental benefits -- reduced reliance on agrichemicals and improved soil sustainability by incorporating animals in the cropping system.

Anton Nicholls, an independent agronomist from CropRight, says that the timing of grazing is critical, it certainly needs to be before the seed head gets to the grazing zone, so it's a matter of waiting until you get enough foliage to be worthwhile grazing but doing it before the seed head gets to grazing height.

It is a low-cost, free grazing opportunity because there could be 1000 kg of dry matter there, that could be worth $100 per hectare at 10 cents or 25 cents if you feed it to lambs. So a $250 premium on top of $1000 wheat crop as well worthwhile, he says.

It also improves cashflow within a month if you are selling it as grazing or within three months if you are selling your own lambs. Most grain contracts involve staggered payments throughout the year, so if you harvest in February you are paid about a third in April a third in July and a third of October. It is a forgotten opportunity.

Treading and pugging can cause damage to the crown of the plant in wet weather, and so is to be avoided.

Craig Mackenzie, of Methven, is currently growing 80 hectares of wheat. He has had trials on his property for two years, last year he successfully grazed some of our own wheat.

It is a very successful management tool when you have very early sown wheat and need to slow the growth down, and also if you are trying to fill a window for feed for lambs, says Craig.

I want to grow a decent crop of wheat and my experience is that there has been no damage from a yield point of view. We did several blocks and several different grazing intensities and there was no issue as far as yield is concerned.

We drilled our wheat on the 23rd of March, which is very early for autumn sown wheat, and this gives us a decent bulk of feed that is worth feeding. We were planting to achieve a target population of 70 plants per square metre which meant a sowing rate of 50 kg seed per hectare.

Craig says he is focused on trying to grow the best crop of wheat that he can, and sees grazing this technique as a management tool to achieve that. The extra income that he might get from lambs would be a bonus, but he is more crop driven than lamb driven.

I would be cautious if it was too wet, that would be the only thing from a hoof damage point of view. I would put larger mobs of lamb on for a shorter period of time rather than small mobs of lambs that might be very picky about what they graze.