Context: ni · feeds d02 (smart food systems)
Summary
Compiled-research report answering “what nitrogen fertiliser rate should a NZ vegetable / market garden use?” — assembled to re-source the model’s vegetable N-demand after Tei 2020 (LIT_108) was found not to support the interim CROP_N_DEMAND_KG_HA["veg"] = 150. The most directly applicable NZ authority it identifies is Reid & Morton (2019), Nutrient Management for Vegetable Crops in New Zealand — already held as OT_069 — which gives crop-specific total seasonal fertiliser-N recommendations, soil-test-adjusted by measured Available N (AMN). The report reads those tables into crop groups (brassicas, leafy greens, root crops, alliums), adds a NZ sector-use proxy of ~135 kg N/ha derived from Journeaux et al. (2019), and brings in AHDB RB209 (UK) and Feller & Fink (2002, Germany) only as international methodology context. The load-bearing caveat it stresses — and the reason there is no single “veg N number” — is that NZ rates are fertiliser recommendations after subtracting measured soil N supply (fertiliser N = crop demand − soil supply), not crop N uptake, so the same crop reads 0 kg N/ha at high soil N and a high figure at low soil N. Its Reid & Morton figures are verified here against OT_069’s raw; its Journeaux / AHDB / Feller figures are unverified context (those primaries are not held).
Key claims
- claim: "NZ crop-specific TOTAL-SEASONAL fertiliser-N recommendations (soil-test-adjusted by 0-15 cm Available N / AMN), read from Reid & Morton (2019): BRASSICAS — cabbage 0-195 (winter) / 0-115 (summer), broccoli 0-125 / 0-70, cauliflower 0-230 / 0-135 (group span 0-230); LEAFY GREENS — lettuce 0-120, spinach 0-90, silverbeet 0-75 (group span 0-120); ROOT CROPS — carrot 0-210 (fertiliser >150 kg N/ha 'rarely economic'), beetroot roots 0-240 / leaves 0-195 (group span 0-240); ALLIUMS — bulb onion 0-140. These are fertiliser rates AFTER subtracting measured soil Available N, NOT crop N uptake, which is why every lower bound is 0."
source_location: "Reid & Morton (2019): brassicas Table 5-1 (Ch5.2); lettuce Ch7.2; carrot Ch6.2; onion Ch8.2 (PARJIB); spinach/silverbeet/beetroot Table 11-1 (Ch11.2). VERIFIED against OT_069 raw — Table 5-1 row confirms 195/115/125/70/230/135."
- claim: "The figures are soil-test-adjusted fertiliser requirements, not crop N demand: 'Fertiliser N required = crop N demand − soil N supply'. A crop reads 0 kg N/ha when measured Available N already meets demand, and a high value at low soil N — so there is no single fixed 'vegetable N demand' number; the honest model form is a soil-N-dependent range, or a crop-specific value."
source_location: "Reid & Morton (2019) Ch5.2 + Tables 5-1 / 11-1; corroborated by FAR Focus 14 (2021) 'Fertiliser nitrogen required = Crop nitrogen demand − Soil nitrogen supply'. VERIFIED against OT_069 raw (AMN / Available-N method, Ch on soil supply)."
- claim: "Vegetable residues return large organic N to soil — a broccoli crop at Pukekohe left 183 kg N/ha (71% of total crop N uptake) in leaves and stems after harvest — which is the nutrient-loop-relevant term (residue mineralisation credits) and part of why brassicas are high-residual-N crops."
source_location: "Reid & Morton (2019) Figure 5-1 / Ch5.2. VERIFIED against OT_069 raw ('for broccoli 183 kg N/ha (or 71% of the total uptake)')."
- claim: "A whole-garden / mixed-vegetable sector-use proxy of ~135 kg N/ha is DERIVABLE but is NOT a recommendation and its primary is NOT held: Journeaux et al. (2019) report vegetables used 5,670 t N fertiliser over 42,141 ha in 2017 → 134.55 kg N/ha. Journeaux's own model crop-event rates (cauliflower 235, cabbage 400, spinach 150, broccoli 150, onion 140, carrot 125, squash 80 kg N/ha) show a single 'garden average' hides order-of-magnitude crop-to-crop variation. LEAD ONLY — Journeaux 2019 not retrieved/verified."
source_location: "Journeaux et al. (2019) Value of N Fertiliser, Tables 1, 59-60, 62 — cited by the compiled report; PRIMARY NOT HELD, figure unverified."
- claim: "International context (NOT model inputs; primaries not held): AHDB RB209 §6 (UK) indexes N by a Soil Nitrogen Supply (SNS 0-6) system not interchangeable with NZ's AMN tables. Feller & Fink (2002, Germany) give Nmin TARGET values (soil mineral N + fertiliser), e.g. broccoli 307, cauliflower 297, white cabbage 272, lettuce 149, spinach 166, carrot 100, beetroot 227, onion 118 kg N/ha — these are targets minus starting Nmin, NOT fertiliser application rates."
source_location: "AHDB RB209 §6 (2021); Feller & Fink (2002) Acta Hortic. 571:195-201, Table 1 — cited by the compiled report; PRIMARIES NOT HELD, figures unverified."Neobiome Intelligence relevance
Re-sources the vegetable N-demand the nutrient-loop model needs. LIT_108 (Tei 2020) was found NOT to support CROP_N_DEMAND_KG_HA["veg"] = 150 (its only ~150 figure is soil-N mineralisation potential, not crop demand). This compiled research supplies the NZ replacement, anchored on the held primary OT_069 (Reid & Morton 2019).
What the modeling work should take (and not take):
- The defensible NZ figures are crop-specific, soil-test-adjusted ranges (brassicas 0-230, leafy 0-120, roots to 0-240, onion 0-140) — verified against OT_069. There is no single “veg = 150”; the honest model form is a range or a crop-set value, not a point constant.
- If a single mixed-veg proxy is unavoidable, the ~135 kg N/ha sector-use figure (Journeaux 2019) is closer to reality than 150 — but it is a LEAD (primary not held) and explicitly not a recommendation, so it should enter flagged low-confidence, if at all.
- Do NOT cite Tei 2020 for veg N-demand. The residue-N term (broccoli 183 kg N/ha / 71% uptake) is the piece that couples to the excreta/residue nutrient-loop.
- AHDB RB209 and Feller & Fink Nmin targets are not fertiliser rates and their primaries are not held — context only.
Parameter value NOT changed here — this is the sourced evidence; the actual CROP_N_DEMAND cell change is the modeling work’s call.
Research targets
Research gaps
- No new RT opened. Closes the evidence side of the LIT_108-flagged veg-N re-source: the NZ authority is OT_069 (held). If the model later needs the Journeaux sector proxy or the AHDB/Feller targets applied, those primaries would need retrieving + verifying first (they are unheld here).
Retrieval provenance
AI-compiled deep-research report delivered on 2026-07-25; the exact generating tool and prompt were not captured in the delivered file. Values are AI-extracted and unverified until spot-checked, per wiki policy — with the following exception recorded at ingest: the Reid & Morton (2019) figures were verified against the held primary OT_069 (pdftotext -layout of OT_069’s raw): Table 5-1 brassica rates (195/115/125/70/230/135), broccoli residue 183 kg N/ha = 71% of uptake, carrot “>150 kg N/ha rarely economic”, the AMN/Available-N method, and the 20/50 kg N/ha split rules — all confirmed. The Journeaux (2019), AHDB RB209 and Feller & Fink (2002) figures were NOT verified (those primaries are not held) and are carried as context/leads only.
Notes
- Primary held. The retrievable primary is OT_069 (Reid & Morton 2019), already in the corpus. The N-rate content this report surfaces was also added to OT_069 (which previously held yields only).
- data_quality: medium. AI-compiled synthesis; only the Reid & Morton leg is verified against a held primary, the rest is context.
- Scope.
context: ni, feeds d02. No NZ-specific change made to any engine cell here.
Connections
Links to
Referenced by
Sources (1): OT_069
EDT domains (1): D02: Smart Food Systems & Agriculture