1. Being dollar wise about using N Rex Webby, AgResearch Ruakura

2. Various studies Sensitivities around cost of N, product value, response rate, amount of N applied and N leaching –For a mixed sheep and cattle farm –Ewes scanned twins set stocked for lambing –Improving efficiency using N

3. For a mixed sheep and cattle farm Study based on: –Farm size 1000 ha –Potential annual pasture production8324 kg DM/ha/year –Lambing %125% N timed to give most benefit

4. Product per ha and amount of N applied

7. Results for the mixed farm analyses Farm stocking rate and production increased with higher N Financial return was highest at 20 and 40 N rates N leached increased in a curvilinear fashion as N application rate increased

8. N and twining ewes N applied 31 July Ewes scanned twins set stocked at 6.5 ha Based on 40 kg N/ha at 15:1 North facing steep hills Weaning 155% Amount of N applied decreases or increases depending on response rate All lambs at weaning valued $/kg live weight Cost of N was set at $1.40/kgN applied

9. Relative returns from differing response rates (kgDM/per kg N) and varying lamb values ($/kg live weight) at weaning.

11. Other sensitivities Lamb survival –At 15:1 if weaning 165% add another $35/ha at $2/kg LWT –At 10:1 if weaning 165% breaks even at $1.50/kg LWT Stocking rate –With no N the stocking rate is 5.6 ewes/ha (with 6.5) –If adjusted stocking rate instead of amount of N result the same Cost of N –At 40kg/N ha a 10c change in cost of a kg N applied is equal to a $4 change in per ha cost.

12. Improving efficiency using N Aim –To maximise the use of late spring pasture growth –Improve utilisation of total feed grown on farm –Improve feed quality throughout the year –Produce more –Make more money Achieved by –Increasing stocking rate by using N strategically –Improving animal performance/efficiency of production –Systems need to be designed for one application of N in spring

13. Pasture cover profile no N vs N

14. Results Utilisation of feed grown increased from 80 to 90% Lower pasture covers throughout year Improved pasture quality throughout year 30 kg more product per ha An extra $37/ha gross margin

15. Summary Highest returns at 20 to 40 kg N/ha N leaching increases curvilinear with increasing amounts of N Little point in applying more than 80 kg N/ha per year on sheep and cattle farms Responses rate (kg DM/kgN) important to profitability Animal performance (lambing% and LWG) important to profitability and economics of using N The strategic use of N can improve efficiencies with flow on benefits improving pasture utilisation and quality leading to higher animal performance