Source
https://www.mpi.govt.nz/dmsdocument/68676-Assessment-of-the-methodology-of-potato-area-and-yield-activity-estimations-used-in-the-NZ-national-GHG-inventory — original source (opens in a new tab; the file is not redistributed)
MPI Technical Paper 2025/05 — NZ potato yield for the national GHG inventory
Advances RT_323 (partial) — the verified primary behind CR_051's potato-yield benchmark (45 t/ha)
MPI Technical Paper 2025/05 (a December 2010 report, later issued in MPI’s 2025 technical-paper series), prepared for the Ministry for Primary Industries by Steve Thomas (Plant & Food Research), Crown Copyright. Figures read verbatim via pdftotext. Verifies the potato national-average yield CR_051 cited; the commercial 51/64 t/ha and onion 45 t/ha remain secondary (RT_323 stays partial).
Summary
An MPI/Plant & Food Research assessment of how NZ potato area and yield are estimated for the national greenhouse-gas inventory. Its NI-relevant fact is the national potato yield: the inventory applies a constant average of 45 t/ha (Statistics NZ + estimate) across all years, and an independent industry cross-check (Potatoes NZ 2009 survey: 10,290 ha, 492,000 t total production) gives 48 t/ha. These are commercial-monoculture staple yields — the closest published NZ crop-yield anchor for the food-domain validation, distinct from (and far above) the model’s mixed biointensive-garden veg_yield (~21–25 t/ha).
Key claims
- claim: "NZ national potato yield: the national GHG inventory applies a CONSTANT average yield of 45 t/ha (from Statistics New Zealand data + estimate), applied to all years. Independent industry cross-check (Potatoes New Zealand 2009 survey): 10,290 ha in production (process 55%/5,551 ha, fresh 36%/3,662 ha, seed <10%/1,077 ha); total production 492,000 t → average yield 48 t/ha."
source_location: "§2.3–2.4 (pdftotext lines 244–245, 291–294); MPI Technical Paper 2025/05"Neobiome Intelligence relevance
Advances RT_323 (partial) — verifies the potato national-average yield (45 t/ha GHG-inventory / 48 t/ha industry) that CR_051 cited as the food-domain validation anchor. The commercial 51 t/ha (Potatoes NZ 2022), 64 t/ha (high-input, Tupu/MPI) and onion 45 t/ha remain secondary → RT_323 stays partial. This is a validation anchor (commercial staple yield), not a model input: the model’s veg_yield (~21–25 t/ha mixed biointensive garden, LIT_058) is a different quantity — potatoes are a bulk staple that far outyields mixed veg. Feeds D02.
Research targets
Research gaps
- RT_323 stays partial: the commercial-average (Potatoes NZ 51 t/ha), high-input (64 t/ha) and onion (45 t/ha, Ecoinvent) figures are still secondary. A NZ permaculture/CSA per-ha veg-yield dataset (RT_307’s real gap) remains missing.
Notes
- Dual dating, resolved 2026-08-11. The title page carries both “MPI Technical Paper No: 2025/05” and “December 2010”. This is a December 2010 report (PDF internal creation date 21 Dec 2010; the newest data it cites is the Potatoes NZ 2009 survey) that MPI later issued in its 2025 technical-paper series (PDF modified April 2025; ISBN 978-1-991330-98-7). Cite as Thomas (2010), MPI Technical Paper No. 2025/05;
year: 2010reflects the document date and the series number stays 2025/05. Treat all yield figures as 2009/2010 vintage. - Public home: the MPI document service (dmsdocument 68676, linked in
url:), listed on MPI’s Agricultural Greenhouse Gas Inventory reports page.
Connections
Links to
EDT domains (1): D02: Smart Food Systems & Agriculture
Referenced by
EDT domains (1): D02: Smart Food Systems & Agriculture
Sources (1): OT_108