Table 2.
Is it better to switch from business as usual (BAU) to mitigation (MIT) strategies?
| Scenario or sequencea | Financial performance | Wheat production | |||||
|---|---|---|---|---|---|---|---|
| Annual gross profit £ ha−1 yr−1 (min, max) |
Annual opportunity costb £ ha−1 yr−1 (min, max) |
Scaled-upc annual opportunity costs £ yr−1 (min, max) |
Annual wheat yieldd t ha−1 yr−1 (min, max) |
Annual productivity costb,e t ha−1 yr−1 (min, max) |
Scaled-up annual productivity costsf t yr−1 (min, max) |
||
| LD-LR (low density, low resistance) | |||||||
| Current | BAU | 649 (490; 821) | NA | NA | 4.79 (3.98; 5.58) | NA | NA |
| MIT | 743 (552; 892) | − 94 (− 149; − 60) | − 18,879,026 (− 29,925,265; − 12,050,442) | 4.41 (3.45; 5.74) | 0.38 (− 0.17; 0.74) | 76,319 (− 34,143; 148,622) | |
| Worst case | BBB | 635 (481; 808) | NA | NA | 4.71 (3.93; 5.51) | NA | NA |
| BBM | 665 (501; 830) | − 30 (− 20; − 48) | − 60,25,221 (− 9,640,354; − 4,016,814) | 4.58 (3.74; 5.56) | 0.13 (− 0.05; 0.25) | 26,109 (− 10,042; 50,210) | |
| BMM | 698 (522; 851) | − 63 (− 42; − 98) | − 12,652,964 (− 19,682,389; − 8,435,310) | 4.46 3.56; 5.62) | 0.25 (− 0.11; 0.48) | 50,210 (− 22,092; 96,404) | |
| MMM | 734 (545; 880) | − 99 (− 65; − 150) | − 19,883,230 (− 30,126,106; − 13,054,646) | 4.36 (3.40; 5.68) | 0.35 (− 0.18; 0.67) | 70,294 (− 36,151; 134,563) | |
| LD-HR (low density, high resistance) | |||||||
| Current | BAU | 612 (457; 801) | NA | NA | 4.58 (3.80; 5.47) | NA | NA |
| MIT | 577 (467; 744) | 35 (− 38; 122) | 27,650,724 (− 30,020,786; 96,382,524) | 2.95 (2.07; 4.45) | 1.638 (0.59; 2.37) | 1,287,734 (466,112; 1,872,349) | |
| Worst case | BBB | 578 (433; 774) | NA | NA | 4.39 (3.67; 5.32) | NA | NA |
| BBM | 569 (437; 757) | 10 (− 13; 38) | 7,900,207 (− 10,270,269; 30,020,786) | 3.86 (3.09; 4.99) | 0.53 (0.19; 0.76) | 418,711 (150,104; 600,416) | |
| BMM | 563 (443; 743) | 15 (− 31; 70) | 11,850,310 (− 24,490,641; 55,301,448) | 3.35 (2.53; 4.68) | 1.04 (0.36; 1.50) | 821,622 (284,407; 1,185,031) | |
| MMM | 561 (452; 733) | 18 (− 51; 100) | 14,220,372 (− 40,291,055; 79,002,069) | 2.85 (1.99; 4.39) | 1.54 (0.52; 2.23) | 1,216,632 (410,811; 1,761,746) | |
| HD-HR (high density, high resistance) | |||||||
| Current | BAU | 582 (426; 771) | NA | NA | 4.42 (3.63; 5.31) | NA | NA |
| MIT | 465 (362; 601) | 117 (− 22; 285) | 49,973,132 (− 9,396,657; 121,729,423) | 2.39 (1.94; 2.81) | 2.03 (1.54; 2.51) | 867,055 (657,766; 1,072,073) | |
| Worst case | BBB | 582 (432; 776) | NA | NA | 4.42 (3.67; 5.34) | NA | NA |
| BBM | 542 (414; 676) | 40 (− 5; 100) | 17,084,831 (− 2,135,604; 42,712,078) | 3.74 (3.08; 4.48) | 0.69 (0.53; 0.86) | 294,713 (226,374; 367,324) | |
| BMM | 502 (397; 628) | 80 (− 11; 199) | 34,169,663 (− 4,698,329; 84,997,036) | 3.06 (2.50; 3.61) | 1.37 (1.05; 1.73) | 585,155 (448,477; 738,919) | |
| MMM | 465 (365; 592) | 117 (− 19; 290) | 49,973,132 (− 8,115,295; 123,865,027) | 2.39 (1.94; 2.80) | 2.03 (1.56; 2.54) | 867,055 (666,308; 1,084,887) | |
We investigate this for different initial density and resistance categories. For ‘current’ black-grass densities, we compare 6-year BAU and MIT rotations. For ‘worst case’ black-grass densities, we compare continuous BAU rotations (BBB) with switching from BAU to MIT after 12 years (BBM), 6 years (BMM), and immediately (MMM). Negative values indicate that switching to MIT outperforms BAU. Values in brackets give minimum and maximum values across regions, soil types and sub-categories of initial density-resistance levels. Annual means are obtained by averaging over the whole rotation (for ‘current’ densities, this is 6 years; for ‘worst case’ densities, this is 18 years). For each row of the table, n = 9.
aFor ‘current’ densities, BAU(current density) and MIT(current density) scenarios are compared; for ‘worstcase’ densities, sequences of BAU(worst-case density) and MIT(worst-case density) are compared. BBB = three sequential BAU rotations. BBM = two sequential BAU rotations followed by one MIT rotation. Other sequences follow the same naming logic.
bWhere annual opportunity cost or productivity cost is not exactly the difference between the MIT and BAU figures, this is due to rounding.
cValues are scaled up to the cereal-producing regions in England where we had field sites. For areas included in each region, see Supplementary Table S3.
dWheat yield is in metric tonnes.
eProductivity costs only consider wheat yield; other crops are not considered.
fFor comparison, annual UK domestic wheat consumption is around 15 million tonnes (AHDB 2018).