RD_033: DairyNZ Facts & Figures ch.3 (Dec 2021), NZ regional pasture growth by district (t DM/ha/yr)

Source

https://www.dairynz.co.nz/resources/resource-list/facts-and-figures/ — original source (opens in a new tab; the file is not redistributed)

DairyNZ Facts & Figures ch.3 (Dec 2021) — NZ regional pasture growth by district

The land-conversion term for the grazing side of the food model — resolves RT_389 and RT_386

Chapter 3 (“Pasture-based production systems” > “Pasture growth data for your farm”) tabulates annual pasture yield in t DM/ha/yr for 49 named sites across NZ. Range: 7.6 t DM/ha/yr (Riversdale, Southland, 6 kg N/ha) up to 21.7 (Dunsandel, Canterbury, 280 kg N/ha). This is the missing multiplier that turns OT_171’s per-cow feed demand into hectares. ⚠ All sites are DAIRY-managed; most are N-fertilised and several IRRIGATED. DairyNZ’s own header: “may include nitrogen fertiliser… viewed simply as a guide.” For a low-input community food model, prefer the low-yield cluster (~8-12 t DM/ha/yr) — grouped by low annual yield, NOT by low nitrogen (several of these sites are in fact high-N, e.g. Kotuku 223 kg N/ha) — and treat irrigated high-N Canterbury (17-22) as an upper bound, not a planning figure.

Summary

Chapter 3 of DairyNZ’s Facts and Figures for New Zealand Dairy Farmers (2nd edition, Dec 2021 printing, DNZ30-001) — the industry’s standard grower-facing quick-reference. Its “Pasture growth data for your farm” section (pp.30-38) gives, for 49 named monitoring sites grouped by region, the monthly pasture growth rate (kg DM/ha/day, Jan–Dec) and the derived annual total (t DM/ha/yr), each tagged with the measurement year-range and the nitrogen application rate where known. This is exactly the regional pasture-supply dataset raised as RT_389 (the conversion term for the whole grazing side of the food model) and RT_386 (retrieve F&F ch.3 to complement the ch.4 feed-demand table already held as OT_171).

The raw PDF is the complete 164-page book, so it also contains Chapter 4 “Cow feed requirements” (the subject of OT_171); this page is scoped to the Chapter 3 pasture-growth data, and OT_171 remains the primary page for the ch.4 feed-demand table. The two chapters are the demand side (OT_171: t DM eaten per cow) and the supply side (this source: t DM grown per hectare) of any community dairy / house-cow land calculation.

The dataset’s central caveat is that every site is a commercial dairy platform: N-fertilised (many at 150–330 kg N/ha), several irrigated, and measured on high-performing pasture. Read raw, the numbers describe intensive dairy, not a low-input community garden-pasture. The value for Neobiome is the regional spread and the low-N anchors, which bracket what a community can realistically expect.

Key claims

- claim: "REGIONAL ANNUAL PASTURE YIELD, 49 named sites, t DM/ha/yr. Full spread runs from 7.6 (Riversdale, Southland, 6 kg N/ha, 2007-2012) to 21.7 (Dunsandel, Canterbury, 280 kg N/ha, 2014-2016). Representative fertilised dairy sites: Northland Dargaville-NARF 15.4 (150 kg N/ha), Awanui 16.0, Tomarata 10.0; Bay of Plenty Galatea 15.7; Waikato Ruakura/Newstead 17.7 (175 kg N/ha), Matamata 15.8; Taranaki Waimate West 17.1 (180-200 kg N/ha); Lower North Island Greytown (irrigated) 15.8, Kaiwaiwai (dry) 12.5; Canterbury irrigated LUDF 21.4 (>300 kg N/ha), Culverden 20.0, St Andrews 19.4; Southland Wallacetown 14.3 (176 kg N/ha), Edendale 13.3. [all figures verified verbatim against the district tables in the raw]"
  source_location: "Ch.3 'Pasture-based production systems' > 'Pasture growth data for your district' (2nd ed, Dec 2021), district tables, pp.34-38. Monthly kg DM/ha/day per site; annual t DM/ha/yr total, year-range and N-rate given per site."
- claim: "DATA-QUALITY CAVEAT, VERBATIM: 'Data is based on averages over several years, and may include nitrogen fertiliser. The data should be viewed simply as a guide as it is not often based on more than several years' data.' Each annual figure carries its own measurement window (e.g. 1996-2017, 2007-2012, 2014-2016) and, where known, its nitrogen rate — several sites are marked 'N use unknown'. [verified verbatim]"
  source_location: "Ch.3 > 'Pasture growth data for your district' (2nd ed, Dec 2021), header note above the Northland table, p.34."
- claim: "LOW-YIELD CLUSTER (the model-relevant subset — grouped by low annual yield, NOT by low nitrogen: several of these sites are in fact high-N, e.g. Kotuku 223 kg N/ha, South Hillend 132, Telford 136) sits far below the fertilised mean, at roughly 8-12 t DM/ha/yr: Riversdale 7.6 (6 kg N/ha), Kotuku 9.7 (223 kg N/ha, West Coast), Tomarata 10.0 (N unknown), South Hillend 10.1 (132 kg N/ha), Tapanui 10.2 (60 kg N/ha), Kowhitirangi 10.6 (120 kg N/ha), Woodlands 11.0 (0 kg N/ha, cage-cut data), Telford 11.5 (136 kg N/ha), Seaward Downs 11.8 (94 kg N/ha). Woodlands is the only explicit 0-N site; Riversdale at 6 kg N/ha is effectively unfertilised and is the dataset's floor. [verified verbatim]"
  source_location: "Ch.3 > 'Pasture growth data for your district' (2nd ed, Dec 2021), Lower North Island / South Island tables, pp.36-38."
- claim: "UTILISATION WORKED EXAMPLE (Ch.4, present in this whole-book raw) bridges grown t DM/ha to cows/ha, VERBATIM: 'Annual pasture eaten calculated =16 tonnes DM/ha (from table on page 46), 500 kg cows producing 400kg MS/cow=5.1t DM/cow x 3.13 cows/ha= 16 tonnes DM/ha) Annual pasture growth = 20 tonnes DM/ha ... Annual utilisation % = 16/20= 80% utilisation (assuming no feed other than pasture was used).' This is the same 80% utilisation gross-up carried on OT_171: 20 t DM/ha GROWN supports 3.13 Friesian cows/ha at 80% utilisation. [verified verbatim]"
  source_location: "Ch.4 'Cow feed requirements' > 'Utilisation and wastage' (2nd ed, Dec 2021), annual pasture utilisation example, p.47. Present in this raw (whole book); OT_171 is the primary page for ch.4."

Neobiome Intelligence relevance

Feeds d02_smart_food_systems and self_sufficiency_calculation as the regional pasture-SUPPLY constant (t DM/ha/yr) — the term RT_389 was opened to fill. Paired with OT_171’s feed-DEMAND per cow, it closes the demand→area conversion for any community dairy / house-cow or grazing pathway and retires the model’s reliance on rough stocking-rate guides (URL_032, Northland-only).

The full 49-site district table stays in the held source (Ch.3 pp.34-38) and is deliberately not reproduced here (copyright). Selected exemplar sites and the low-yield cluster are quoted in Key claims; the planning tiers below summarise the spread.

How to use it — three tiers, not one number (all figures RD_033):

Management tierIndicative t DM/ha/yrUse for
Low-yield (low-input target)~8-12 (Riversdale 7.6 → Woodlands 11.0)Low-input community pasture — the planning band (grouped by yield, not N; several sites here are high-N, e.g. Kotuku 223 kg N/ha)
Fertilised dryland dairy~13-18 (most North Island + Southland sites)N-supported but unirrigated
Irrigated high-N Canterbury~17-22 (Dunsandel 21.7, LUDF 21.4)Upper bound only — not achievable without irrigation + heavy N

Demand→area conversion. Using OT_171’s Friesian demand (5.1 t DM eaten/cow/yr) and the source’s own 80% utilisation: at a low-input 10 t DM/ha/yr grown → 8 t eaten/ha ÷ 5.1 ≈ 1.6 cows/ha; at the Canterbury upper bound 20 t DM/ha/yr → 16 eaten ÷ 5.1 ≈ 3.1 cows/ha (matching the book’s own worked 3.13 cows/ha example). This cross-checks URL_032: its ~2 cows/ha implies ~10 t DM/ha (plausible for low-input), while its ~5 cows/ha would need ~25 t DM/ha, above every unirrigated site here — confirming URL_032’s top end does not transfer outside intensive systems.

No engine cell is auto-changed by this ingest. It supplies the parameter and its defensible band; wiring the region-specific figure (or the ~8-12 low-input band) into the food model is a separate, reviewed step, ideally keyed to the NIWA climate layer already in corpus (RD_022).

Notes

  • Authoritative NZ industry reference, downloaded — no retrieval-provenance block required (not AI-prepared). data_quality: high rather than verified: these are DairyNZ’s own multi-year site measurements, industry-standard but each based on only “several years” and not independently corroborated in corpus.
  • The raw is the complete 164-page book (2nd edition, 2017; this printing Dec 2021; DNZ30-001), so it also contains Chapter 4, the subject of OT_171. This page is scoped to Chapter 3; OT_171 is unchanged and remains the primary page for the ch.4 feed-demand table. Read the two chapters on this common Dec-2021 basis.
  • Every site is a commercial dairy platform. N-fertilised (many 150-330 kg N/ha), several irrigated, high-performing pasture. The numbers are an upper envelope for a low-input community, not a like-for-like. The near-zero-N sites (Riversdale 6 kg N, Woodlands 0 kg N) are the closest analogues and anchor the ~8-12 t DM/ha planning band.
  • Vintage: 2nd edition 2017, Dec 2021 printing.

Research targets

Documents to retrieve

  • RT_386 — RESOLVED by this source. RT_386 asked for DairyNZ Facts & Figures chapter 3, the sibling to the ch.4 feed-demand table (OT_171). This raw is the whole book including chapter 3; the pasture-growth district data is captured above. → move RT_386 to Done → RD_033.

Research gaps

  • RT_389 — RESOLVED by this source. RT_389 was the missing NZ regional pasture-growth term (t DM/ha/yr) to convert per-cow feed demand into hectares. The 49-site district dataset above fills it, with the important qualification that all sites are N-fertilised dairy platforms, so a low-input community model should use the low-yield band (~8-12 t DM/ha/yr), not the fertilised mean. → move RT_389 to Done → RD_033.
  • Not raised as new RTs: the ME/quality of a low-input community pasture (needed to size OT_171’s +5%-per-MJ-ME adjustment) and a measured utilisation fraction for hand-managed community grazing remain modelling-judgment parameters, not retrievable documents — already carried as warnings on OT_171. No new RT opened.

Connections

Links to

Sources (3): OT_171 · RD_022 · URL_032

Referenced by

Sources (2): OT_171 · URL_032

EDT domains (1): D02: Smart Food Systems & Agriculture