Crop suitability
Climate does not prohibit crops. Suitability compares a crop with the selected land; it affects the resulting yield within configured limits. Access level and research requirements are separate. Compare the selected crop and farm together, then use the authoritative work review for actual cost, duration and output terms.
Percentage and harvest example
Suitability is stored in hundredths of a percent: 8,000 means 80%, and multiplies yield by 8,000 / 10,000 = 0.8. It does not prohibit planting.
At planting, yield = hectares × base kg/ha × suitability / 10,000 × (1 + combined improvement). Combined improvement adds agronomy plus optional fertilizer 20% and irrigation 15%, capped at 60%. Each agronomy rank adds 5%. A hypothetical 10 ha wheat field at 80%, with base 4,000 kg/ha, fertilizer, irrigation and one agronomy rank yields 10 × 4,000 × 0.8 × 1.40 = 44,800 kg (44.8 t). Even if improvements exceed the cap, this field cannot exceed 10 × 4,000 × 0.8 × 1.60 = 51,200 kg (51.2 t) before deterioration. Existing plantings and finite regrowth cycles retain their recorded yield.