New Zealand Journal of Agricultural Research abstracts
Sustainability of New Zealand high-country pastures under contrasting
development inputs. 6. Fertiliser efficiency
D. SCOTT
AgResearch
P.O. Box 60
Lincoln, New Zealand
Abstract Using 15 years of grazing records from two trials
with 31 different sulphur (S) and phosphorus (P) fertiliser combinations on a
Tekapo/Pukaki high-country soil, the most profitable fertiliser combinations
for long-term sustainable production were determined from consideration of
fertiliser composition, ex-works, transport, and spreading costs, increase in
sheep carrying capacities, and discount rates. In a soil with a high natural
surface-soil P level, the optimum returns were determined solely by elemental-S
fertiliser rates. The estimated greatest net returns from annual applications
rates were at 53 kg S ha-1 yr-1, or between 24 and 39 kg
S ha-1 yr-1 if ratio of return versus input was
considered. Using carrying capacity response functions and elemental-S
oxidation rates, it was estimated that the best long-term sustainable
fertiliser strategy was for 5-yearly applications of 250 kg ha-1 of
2.2-mm coarse-particle elemental S.
Keywords New Zealand; high-country; S; P; economics;
fertiliser; grazing; sustainability
New Zealand Journal of Agricultural Research, 2000, Vol. 43: 525-532
0028-8233/00/4304-0525 $7.00/0 (c) The Royal Society of New Zealand
2000
PDF file of entire paper: medium quality (700K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
