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CCW — Catch Crops (Winter / Efterafgrøder, vinter)

Summary

Sowing of catch crops after a winter main crop (e.g. winter wheat). Unlike CCS, the catch crop must replace a winter cash crop, making this measure substantially more expensive.

Eligibility / Potential area

PotV(i,"CCW") = Sum(cy, wc(i,cy)) / 5
Where wc(i,cy) = IniPotV(i) if the crop in year cy is a winter crop (crop codes 11, 29, 30), else 0. Average over 5 crop years. Fields dominated by spring crops will have low CCW potential.

N Effect

Identical to CCS (same values, different crop context): 

NEffM(i,"CCW"):
  livestock ≥ 0.8, soil < 5 (sandy):  45 kg N/ha/yr
  livestock ≥ 0.8, soil ≥ 5 (clay):   24 kg N/ha/yr
  livestock < 0.8, soil < 5 (sandy):   32 kg N/ha/yr
  livestock < 0.8, soil ≥ 5 (clay):    12 kg N/ha/yr

P Effect

None.

Cost

CostM(i,"CCW"):
  soil < 5, livestock < 0.8:  2,016 DKK/ha/yr
  soil < 5, livestock ≥ 0.8:  1,980 DKK/ha/yr
  soil ≥ 5, livestock < 0.8:  3,168 DKK/ha/yr
  soil ≥ 5, livestock ≥ 0.8:  3,120 DKK/ha/yr
~5–8× more expensive than CCS because it displaces a winter cash crop (winter wheat, winter barley, etc.) which has high gross margins — especially on clay soils.

Retention type

TR (Total retention)

Mutual exclusions

Member of mem(j) — at most one measure per field.

Data sources

  • Cost and N effect values: hard-coded in TargetEcon 2026.gms
  • Winter crop identification (MarkAccess(i,cy)): MarkAccess2.inc

Catalog source

Same as CCS: DCA Rapport nr. 174, Chapter "Efterafgrøder" (p. 33–58). The catalog treats all catch crops in a single chapter regardless of whether they follow spring or winter crops. The CCS/CCW distinction in TargetEcon is a cost distinction, not an N-effect distinction — the catalog confirms this: the N reduction depends on soil type and livestock intensity, not on whether the preceding crop was spring or winter sown.

Budget cost from catalog: 7–167 DKK/kg N (same as CCS). This means the catalog does not differentiate CCW costs from CCS costs — the high CCW costs in the model reflect the model developer's assessment of the additional opportunity cost from replacing a profitable winter crop (not directly from the catalog).

Notes

  • Despite identical N effects, CCW is rarely cost-effective compared to CCS due to its high cost. It tends to be selected only in catchments with limited alternative measures.
  • The large cost difference between CCS and CCW (same N effect) is one of the clearest demonstrations of the opportunity-cost-driven approach in this model.
  • The catalog's CE ranges (7–167 DKK/kg N) apply to CCS; CCW would be at the upper end or above this range due to higher opportunity costs.

Scenario appearances

To be filled as scenarios are documented.

  • CCS — spring-crop counterpart; same N effect, far lower cost
  • Retention types — CCW uses TR (total retention)
  • Cost concepts — fixed cost only; no prodcost; 5–8× more expensive than CCS
  • N Reduction — CCW appears in TR set