Table 5.
Top ten crops/crop combinations and land required for optimized provision of dietary energy and protein per unit cropping area (ha) in the “no nuclear winter” scenario (Scenario NW0).
| Prioritized frost resistant crops/crop combinations | Total cropping area required (ha)* | Equivalent % of current area in New Zealand used in cropping | Current New Zealand production (ha) |
|---|---|---|---|
| 1) Wheat (96.8% of area), carrots (3.2% of area) | 116,000 | 18.6% |
Wheat: 43,500 ha in 2021 64 Carrots: 1851 ha in 2017 65 |
| 2) Sugar beet (100% of area); when excluding wheat | 141,000 | 22.7% | Sugar beet: The amount currently grown was not identified (it is grown as a livestock feed, see Table 3) |
| 3) Oats (100% of area); when excluding wheat and sugar beet | 145,000 | 23.4% | Oats: 5500 ha in 2022 66. It has been higher in previous years (e.g., 8900 ha in 2010) |
| 4) Onions (88.6% of area), carrots (11.4% of area); when excluding wheat, sugar beet and oats | 159,000 | 25.6% |
Onions: 5588 ha in 2020 67 Carrots: 1851 ha in 2017 65 |
| 5) Cabbage (white) (60.9% of area), barley (39.1% of area); when excluding all the crops in the rows above | 202,000 | 32.5% |
Cabbage: Data are combined with broccoli and cauliflower: 3632 ha in 2017 65 Barley: 44,200 ha in 2021 64 |
| 6) Canola (51.8% of area), cabbage (savoy) (48.2% of area); when excluding all the crops in the rows above | 229,000 | 37.0% |
Canola: Area not identified but reported production was 2200 tonnes in 2020 68 Cabbage: Data are combined with broccoli and cauliflower: 3632 ha in 2017 65 |
| 7) Linseed (93.2% of area), parsnip (6.8% of area); when excluding all the crops in the rows above | 304,000 | 49.0% |
Linseed: Estimated at 1910 ha in 2019 69 Parsnip: Data not identified |
| 8) Rye (95.9% of area), lupins (4.1% of area); when excluding all the crops in the rows above | 311,000 | 50.1% |
Rye: Data not identified Lupins: Data not identified |
| 9) Swede (61.4% of area), field beans (38.6% of area); when excluding all the crops in the rows above | 414,000 | 66.8% |
Swede: Area not identified. A closely related crop (turnip) had reported production of 75,000 tonnes in 2020 70 Field beans: Data are combined with peas: 4705 ha in 2017 data65 |
| 10) Cauliflower (100% of area); when excluding all the crops in the rows above | 622,000 | 100.2% | Cauliflower: Data are combined with broccoli and cabbage: 3632 ha in 2017 65 |
*For most of these crop/crop combinations, an exact optimization solution could be obtained (i.e., exactly the specified amounts of both energy and protein for the whole population). The exceptions involved excess energy available once the required amount of protein was achieved (i.e., the options involving sugar beet [5% excess] and oats [12%]). Similarly, for there being excess protein once energy requirements were met in one case (the cauliflower option: 9% excess).