Functionally rich crop rotations increase calorie and macronutrient outputs across Europe

Increased crop diversity in cereal-dominated rotations can enhance crop protection, nutrient use efficiency and climate change adaptation. Nevertheless, it is argued that replacing cereals in rotations diminishes food production, threatening food security. Here we compared outputs of calories and macronutrients (carbohydrates, proteins, fats) for human consumption from cereal monocultures, cereal-only rotations and rotations including two or three functionally distinct crop types (cereals plus root and oil crops, legumes or ley) in 16 long-term experiments across Europe. Rotations with three functional types produced more calories and macronutrients than cereal monocultures and cereal-only rotations with forage crops used to produce milk. Carbohydrate gains depended on growing conditions and crop choice. Advantages increased over time but were lost with forage crops used for beef or biofuel. Functionally rich rotations provided macronutrient proportions closer to recommended human diets. Our analysis shows no trade-off between functionally rich rotations and food production or agricultural land expansion.