Spring nitrogen use on hill country

March 2005
Matt and Sue Latham are the sixth generation to farm Wairewa at Little River in Banks Peninsula. They aim to improve the property and use it to provide their family, Guy 6, Angus 4, Georgina 2 with the lifestyle they want. With this in mind they took on the role of Meat and Wool Innovations Central Canterbury Monitor Farmers, and our now heading towards the end of their second season.

Their property, Wairewa, is 703 effective hectares on the hills above Little River, Banks Peninsula. Matt farms in partnership with his father, Bill, and they lease the farm from a Trust. 225ha of the property faces north, 200ha faces south, and 150ha is warmer west facing country that includes a 105ha deer block. Only 25ha is easily cultivated. Elevation is about 40m up to 640m. Annual rainfall on average is 1070mm. Winters on the property are particularly cold and summers particularly dry, so it is an inherently challenging property to farm. Stock is :

  • 2800 Romney ewes going to the ram of which 800 are two-tooths

  • 147 cows

  • 45 18-month heifers

  • 30 calves

  • deer 380 mixed age hinds

The Lathams financial goals are to increase earnings before interest and tax (EBIT) from the 02/03 level of $105,000 to $150,000 by 2007. To do this they are:

  • Increasing subdivision about two-thirds of the property is now in paddocks of about 10ha. The aim is to mob stock the ewes and graze rotationally so that DM utilisation is improved. Many paddocks have one aspect. In the past some paddocks have had areas that faced north, west and south, and stock would overgraze the north slopes and undergraze the southern ones. Now weeds are disappearing and poorer pasture species browntop, coxfoot, Poa etc are slowly being replaced by ryegrass and clover.

  • Improving flock genetics instead of rearing their own replacements they are now buying in ewe hoggets with higher production potential from the Nth Island. Their 2ths and 4ths are now of the new genetics and from now on they will breed their own replacements.

  • Improving ewe nutrition in the past the flock has struggled to maintain liveweight between weaning and tupping, resulting in poor lambing performance. The aim recently has been to maintain weaning weight through to tupping, but this year is the first time they will have achieved it. It has been a better season, and they have also drafted out light ewes for feeding on a summer crop.

  • Using nitrogen they have used some N fertiliser in autumn in the past, and last spring they also applied N in the spring, with considerable success.

  • Adjusting stock numbers they are now carrying a few more ewes, fewer cattle and about the same number of deer (same number of SU overall). In particular they are quitting steers at 18 months and not carrying stores through a second winter. This frees up feed for the ewes over autumn and winter.

Lambing % - prior to starting on the Monitor Farm programme lambing averaged 105%. In the first year they achieved 118%, and in the season just ending they achieved 127%. Matt believes that the measures above should see that figure lifted to close to their target of 135% in the coming season. Last year the ewes scanned at 155%, this year at 165%, so they have more ewes carrying twins and they will need a higher feed intake, hence the fewer cattle and more nitrogen policies.

Normally nitrogen is applied as a compound fertiliser in the autumn to boost winter feed. They agreed last year to take part in a trial of spring application of Nitrogen, and so in the autumn they checked P and S levels and put on appropriate maintenance dressings along with the usual N.

The intention was to apply N around the 20th August, but there was still snow on the ground and it wasnt until early September that it disappeared and soil temperatures rose sufficiently to warrant N application. On 6th Sept they applied 60kg N/ha (120kg Summit Quinphos Sustain) to two areas, one facing north and the other facing west. Alongside each of these was a control paddock of similar size.

Pasture covers on treated and control blocks were similar prior to application, and ewes were set stocked prior to lambing at an appropriate level for the cover, aspect and the number of lambs the ewes were carrying. Stocking rates were around 8E/ha (singles) for one pair of blocks, and 6.0E/ha (twins) for the other. By November stocking rate on the untreated blocks had dropped by about 1E/ha, but on the N treated blocks it had increased to just over10E/ha.

As expected, pasture cover and pasture growth increased considerably on the treated blocks as did the total weight of animals carried. $ returns from the treated blocks (measured in lamb weight plus increase in ewe liveweight) were around 90% higher than the untreated blocks.

The cost of N applied was $60/ha, and the net increase in margin due to N was $177/ha in one case and $240/ha in the other.

Matt is rapt. He comments that it was a lot of work monitoring stock weights and pasture covers etc, but in the end it was worth it if he didnt have those figures he would not have known the extent of benefit that he had gained from N.

This autumn there will probably be a trial set up to compare autumn and spring applied nitrogen. If so, it will involve putting on autumn nitrogen and tracking growth right through to the spring, and then doing a spring application as well on companion blocks. He suspects that applying a higher rate of nitrogen in the autumn will result in stronger growth and a better pasture cover through the winter, and it should not be necessary to graze pastures as hard as they have had to in the past. In theory, he says, even though all the nitrogen would have been used up by spring, plants should be healthier and growth should take off earlier, so they shouldn't need spring nitrogen.

The weather will always have a large effect on production because of its harshness in extremes, but Matt doesnt see this as a difficult property to farm its where he has always been and he is used to it.
The Lathams are on track to increase their EBIT as planned, but in the past year they have had some larger than expected expenses that have eaten into net profit.

Matt really enjoys farming and has no problems getting up each day and going out to work on the property. As a sixth generation farmer he feels it is a privilege to be there and to have the opportunity to work the land. His main aims are quality family time, and being successful, which for him means being able to live the lifestyle he wants.