Source
doi:10.5281/zenodo.2401910 — original publication (opens in a new tab; the file is not redistributed)
Reid & Morton (2019) — Nutrient Management for Vegetable Crops in New Zealand
Authoritative NZ per-crop vegetable yields — the basis to firm the food slice's
veg_yieldThe HortNZ / Plant & Food Research / Fertiliser Association technical manual (Reid & Morton, 1st ed. Jan 2019), giving field-experiment-based potential / field / marketable yields (t/ha) and nutrient recommendations for 11 NZ vegetable crops. Its NI value is the per-crop marketable (edible-supply) yields, which let the model firm
veg_yield(F1_Food). Yields are COMMERCIAL-scale; a diversified community-garden figure is derived from them (with a “diversity penalty”). Advances RT_061 — but RT_061’s community/small-plot (0.01–1 ha) gap remains.
Summary
The definitive NZ nutrient-management reference for field vegetables, published by Horticulture NZ on behalf of the Vegetable Research & Innovation Board and the Fertiliser Association, funded by Plant & Food Research (Sustainable Agricultural Ecosystems Programme). For each of 11 crops it tabulates potential, field, and marketable yields from replicated NZ field experiments, then derives nutrient (N/P/K) recommendations. For the Neobiome food slice, the marketable-yield tables are the load-bearing content: they give defensible NZ per-crop edible-supply yields spanning ~10–80 t/ha, from which a diversified-garden veg_yield can be triangulated.
Key claims
- claim: "Marketable (edible-supply) yields differ greatly from field/biomass yields, and the 'harvest fraction' varies enormously by crop: e.g. for the brassicas only ~75% / 18% / 37% of total plant biomass goes to the harvested portion for cabbage / broccoli / cauliflower respectively. So the SAME field biomass yields very different marketable tonnages — the core reason a diversified garden yields far less per ha than a high-harvest-fraction monoculture."
source_location: "Ch5 §5.1 p.54 (brassica harvest fractions); Ch4 §4.1 p.44 (squash potential vs marketable)"
- claim: "NZ marketable vegetable yields (t/ha, from replicated field experiments): buttercup squash 16–32 (mid-season 24–32, early/late 16–22); cabbage 45 (summer) – 68 (winter); broccoli 11 (summer) – 16 (winter); cauliflower 22 (summer) – 33 (winter); lettuce 18–30; bulb onions ~50–80 fresh (long-keeper; up to ~100 potential for fresh types); process peas ~10–15; process beans ~27 (pods)."
source_location: "Ch4 §4.1 p.44–45 + Table 4-1 p.50; Ch5 §5.1 p.54; Ch7 §7.1/Table 7-1 p.78; Ch8 §8.1 p.81–82 + Table 8-1 p.87; Ch9 §9.1 p.90; Ch3 Table 3-1 p.41"
- claim: "High-yielding staple/storage crops anchor the top of the range — bulb onions ~50–80 t/ha fresh, cabbage 45–68, carrots ~50 (process up to 120), potatoes ~27–60 — while diet-diversity crops anchor the bottom — broccoli 11–16, peas 10–15, lettuce 18–30. A diet-covering garden must grow both, so its effective whole-plot yield sits well below the best monoculture."
source_location: "Ch6 §6.1 (carrots); Ch8 §8.1 (onions); Ch10 §10.1 (potatoes); Ch5 §5.1 (brassicas); Ch9 §9.1 (peas); Ch7 §7.1 (lettuce)"
- claim: "Yields are 'potential → field → marketable', with field typically ~80% of potential under water stress and marketable lower again after grading/trimming — i.e. use MARKETABLE weight for an edible-supply (self-sufficiency) model, not potential/field. (E.g. squash: potential 40 → field-stressed ~32 → marketable 24–32 t/ha.)"
source_location: "Ch4 §4.1 p.44 ('Potential yields can seem high…marketable yields less again')"
- claim: "Crop-specific TOTAL-SEASONAL fertiliser-N recommendations (soil-test-adjusted by 0-15 cm Available N / AMN; fertiliser N = crop demand − measured soil N supply, so 0 kg N/ha when soil supply already meets demand, NOT crop N uptake): brassicas — cabbage 0-195 (winter) / 0-115 (summer), broccoli 0-125 / 0-70, cauliflower 0-230 / 0-135; lettuce 0-120; spinach 0-90; silverbeet 0-75; carrot 0-210 (fertiliser >150 kg N/ha 'rarely economic' — deep N scavenging); beetroot roots 0-240 / leaves 0-195; bulb onion 0-140 (PARJIB-based)."
source_location: "Table 5-1 (Ch5.2 brassicas — raw table confirms 195/115/125/70/230/135); Ch7.2 (lettuce); Ch6.2 (carrot); Ch8.2 (onion); Table 11-1 (Ch11.2 spinach/silverbeet/beetroot)"
- claim: "Vegetable residues return large organic N to the soil (the nutrient-loop mineralisation credit): a Pukekohe broccoli crop left 183 kg N/ha — 71% of total crop N uptake — in leaves and stems after harvest. Starter soluble N is limited to ~20 kg N/ha (up to 50 for winter-planted crops), with the remainder split at no more than 50 kg N/ha per side-dressing."
source_location: "Figure 5-1 / Ch5.2 (broccoli residue 183 kg N/ha = 71% of uptake); Ch5.2 + Ch11.2 (20/50 kg N/ha split-application rules)"Neobiome Intelligence relevance
Project specification (locked, 2026-06-10): Neobiome food production is modelled on regenerative / permaculture / biodynamic / organic / biointensive systems ONLY — conventional/industrial yields are not adopted as model benchmarks. See decision D_001.
This is the authoritative NZ conventional per-crop yield reference — recorded as the contrast baseline only, NOT the Neobiome veg_yield benchmark. Its per-crop marketable yields (onions/cabbage/carrots 45–80 t/ha; broccoli/peas 11–16) and the harvest-fraction insight (broccoli ~18% marketable) characterise commercial monoculture production; a conventional diversified market garden would blend to ~25–35 t/ha, but under D_001 this figure is not used to set the model. The model’s veg_yield must instead come from regenerative/biointensive evidence (RT_061, now scoped to that system class — NZ small-plot regenerative + the international biointensive literature). This source’s lasting NI value is therefore (a) the conventional contrast, and (b) the harvest-fraction / marketable-vs-field methodology (use marketable edible-supply weight, whatever the system). Advances RT_061 (does not close it): it is commercial field-scale conventional data, whereas RT_061 seeks community/small-plot regenerative outcomes.
Nitrogen management (added 2026-07-25) — the nutrient-loop dimension
Beyond yields, this manual is the NZ authority for vegetable fertiliser-N rates (the two N-rate key_claims above). It is the corpus’s verified NZ source for the model’s vegetable N-demand, re-sourcing it after LIT_108 (Tei 2020) was found not to support CROP_N_DEMAND_KG_HA["veg"] = 150. Note these are soil-test-adjusted fertiliser recommendations (fertiliser N = crop demand − soil supply), not crop N demand — so there is no single fixed veg-N number, and the residue-N term (broccoli 183 kg N/ha, 71% of uptake) is the piece that couples to the excreta/residue nutrient loop. Unlike the yield content, the N-rate content is system-agnostic (fertiliser agronomy), so it is not constrained by the D_001 conventional-yield exclusion. Compiled cross-reference: CR_056.
Research targets
Research gaps
- RT_061 (advanced, stays open): NZ community/small-plot (0.01–1 ha) diversified market-garden yield, and NZ organic/regenerative vegetable-yield data, remain ungathered — this manual gives the commercial per-crop basis but not the community-garden whole-plot figure (which is here derived/triangulated, not directly sourced).
- (no new RT — the diversified-garden derivation is documented in NI relevance; Curran-Cournane & Rush 2021 provides the diet-coverage rationale.)
Connections
Links to
Decisions (1): D_001: Neobiome food production — regenerative…
Referenced by
Decisions (1): D_001: Neobiome food production — regenerative…
Sources (1): CR_056
SSI indicators (1): I02: Food Security & Sustainable Agriculture
EDT domains (1): D02: Smart Food Systems & Agriculture