Measure forage dry matter yield per hectare using the quadrat cutting method. Estimate total pasture production and carrying capacity.
This calculator converts quadrat sample weights into tonnes of dry matter per hectare. Enter quadrat dimensions, fresh sample weight, dry matter percentage, and field area to estimate total forage production. Essential for stocking rate decisions.
A 0.5 m × 0.5 m quadrat yields 500 g of fresh grass at 25% DM. That's 2 kg/m² fresh = 20 tonnes/ha fresh = 5 tonnes DM/ha. For a 10 ha field, total production is 50 tonnes DM — enough to carry ~3.4 cow-equivalents for a year (at 12 kg DM/day each).
✓ Expert Reviewed: This calculator and its content have been reviewed by agricultural experts. Formulas are based on NRC, FAO, and university extension recommendations. For site-specific advice, consult your local agronomist or veterinarian.
Cut and weigh all forage in a measured quadrat. Enter quadrat width and length in meters, fresh sample weight in grams, dry matter percentage, and total field area in hectares. Click Calculate.
The Forage Yield Calculator uses the standard quadrat method recommended by extension services. Forage DM yield drives stocking rate, hay production estimates, and pasture management decisions. NRC and FAO provide guidance on sampling methodology.
Sample area = width × length (m²). Fresh yield/ha = (sample weight g ÷ sample area m²) × 10,000 ÷ 1,000 (g to tonnes). DM yield = fresh yield × DM%. Total DM = DM yield/ha × field area. Take 5-10 quadrats per field for reliability.
Quadrat 0.5×0.5 m = 0.25 m². Sample = 500 g. Fresh yield = 500/0.25 × 10,000/1,000 = 20,000 kg/ha = 20 t/ha fresh. At 25% DM = 5 t DM/ha. 10 ha = 50 t DM total. Carrying = 50,000 kg ÷ (12 kg × 365) = 11.4 cow-years.
Common mistakes: taking only one quadrat (use 5-10 samples), not drying sample for accurate DM%, measuring unrepresentative patches. Tip: sample at grazing height, not tallest grass. DM% can be estimated by feel or measured with a microwave/oven. Consult extension for local benchmarks.
Cut all forage within a measured frame (typically 0.25-1 m²) at grazing height. Weigh immediately for fresh weight. Take a sub-sample of ~100-200 g, dry in oven at 60°C for 48 hours, reweigh for DM%. Repeat 5-10 times across the field. Average the results. Extension services recommend 10 quadrats per management unit.
Yields vary widely: permanent pasture 3-6 t DM/ha/year, improved pasture 8-15 t DM/ha, irrigated or high-input forage 15-25 t DM/ha. Annual: warm-season grasses peak in summer, cool-season in spring/fall. NRC and extension publications provide regional benchmarks.
DM% can be estimated by: (1) Oven drying — most accurate (60°C, 48h), (2) Microwave method for quick estimates, (3) Feel and appearance — lush grass ~20-25% DM, wilting ~35-45%, cured hay ~85-90% DM. For critical decisions, use lab analysis. FAO recommends lab testing for precision ration balancing.
Carrying capacity = total DM produced ÷ (daily DM intake × days). Example: 5 t DM/ha × 10 ha = 50,000 kg DM. At 12 kg/day per cow = 4,167 cow-days ÷ 365 = 11.4 cow-years. Adjust for pasture utilization (50-70%) — animals don't graze everything. Leave 30-50% residual cover.
Sample at typical grazing height, not at maximum growth. For rotational grazing, sample just before each paddock graze. For hay, sample at boot/early head stage. Sample at the same time of day to avoid moisture fluctuations. Record weather conditions. Extension recommends sampling every 2-4 weeks during growing season.