Grass yield: factors, management and the Normandy benchmark

Herb yield is a key indicator of forage productivity, ranging from 4 to 5 tonnes of dry matter per hectare annually in France, with variations up to double in the same field due to annual, seasonal, climatic, and altitudinal factors. Yield depends on soil type, fertilization, and pasture management. Effective practices include limiting pasture aging, maintaining or introducing productive species, improving soil fertility with organic amendments, and applying mineral nitrogen in winter and spring. Reducing mowing or grazing frequency can boost yield but reduce quality. Keeping forage on the field during summer preserves yield. However, actual herd utilization depends on both quantity and quality of intake. Early mowing improves quality and intake, while late mowing increases volume and fiber. Legumes must be mowed at the right time to preserve leaves. At pasture, low grazing height with high stocking pressure maximizes per-hectare value, even if individual animal performance dips slightly. In Normandy, the Praicos n°4 reference guide classifies fields into A (12–14 t), B (10–11 t), C (8–9 t), D (5–6 t) in wet conditions; 14–17 t, 12–14 t, 10–11 t, 7–8 t in good conditions; and 11–12 t, 11–12 t, 9–10 t, 5–6 t in dry conditions.