Source
https://mro.massey.ac.nz/handle/10179/4191 — original source (opens in a new tab; the file is not redistributed)
Context: ni · Feeds D02 + D03 (NZ potato crop water requirement)
Summary
A Massey University PhD field trial (Palmerston North) that measures potato water use for heritage (Taewa) and modern cultivars under irrigation and nitrogen management. It gives the model a real NZ field-measured potato crop water requirement, computed with the same FAO Kc method the model uses (OT_218), and so hard-sources the potato leg of CROP_CWR_MM. It is the open full-text of the otherwise paywalled Fandika et al. 2016 journal paper.
Key claims
- claim: "NZ POTATO CROP WATER REQUIREMENT (potential, FAO Kc method), Massey/Palmerston North. Verbatim: 'The growing seasons for Taewa and modern potato were 170 and 140 days, with potential crop water requirements of 611 mm and 491 mm, respectively.' So heritage Taewa needs ~611 mm over 170-180 days and modern potato ~491-550 mm over 140-150 days. [verified verbatim against the raw, Ch.5 Table 5.2 p.146]"
source_location: "Fandika (2012), Chapter 5, Table 5.2 / Fig. 5.2, p.146 (also General Discussion ~p.230)."
- claim: "NZ POTATO ACTUAL WATER USE + WATER-USE EFFICIENCY. Actual ETc (consumptive use) averaged 523.4 mm (full irrigation), 416.4 (partial), 355.6 (rainfed) = 92% / 73% / 60% of the potential requirement. Water-use efficiency (fresh tuber yield per m³ of crop water used) ranged 3.3-12.4 kg/m³ across cultivars (modern Agria up to 12.4; heritage Tutaekuri as low as 3.3-4.5). [verified against the raw; ⚠ WUE unit is kg/m³, not kg/ha/mm]"
source_location: "Fandika (2012), Ch.5 Table 5.2 (actual ETc); General Discussion §7.5.2.1 p.222 (WUE range)."Model use
- Hard-sources the potato value in
CROP_CWR_MMin D02: use ~550 mm for a modern NZ cultivar (491 modern to 611 heritage), now backed by an actual NZ field trial rather than FAO-56 Kc alone. Method-consistent with OT_218. LIT_130
Notes
- Basis. The 491-611 mm is the potential crop water requirement (FAO Kc); the field-realised actual ETc is 356-523 mm depending on irrigation. Heritage Taewa use more water (later maturity) at lower yield-based efficiency.
- Provenance. Open PhD thesis from Massey Research Online (handle 10179/4191), authoritative first-party, figures verified verbatim against the raw. Supersedes the paywalled 2016 journal paper for our purposes.
- Scope. context ni, feeds d02 + d03.
Connections
Links to
EDT domains (2): D02: Smart Food Systems & Agriculture · D03: Water, Waste & Circular Systems
Sources (1): OT_218
Referenced by
EDT domains (2): D02: Smart Food Systems & Agriculture · D03: Water, Waste & Circular Systems