OREGON STATE UNIVERSITY
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Herbaceous, cool-season, perennial bunchgrass. Extensively used as a forage, as pasture and erosion control in mixtures with other grasses and legumes, and as hay and silage, typically as a monoculture. Best suited to well-drained soil conditions.Highly palatable to all livestock classes. No animal health issues, e.g. does not cause bloat.
Perennial bunchgrass
Habit: Erect bunchgrass, graminoid
Life: Moderate
Temperature: -17 to 31°C; Winter hardy
Precipitation: minimum of 350-550mm
pH: 5.6-8.4
Drainage: ED-MWD
Salinity: Moderately sensitive, 1.5-3 dS/m
Drought tolerance: Medium
Flood tolerance: Medium, tolerates 15-25 days
Climate suitability characteristics in the following table are based on field experiments and forage agronomist experience. Soil factor data are based on values provided in Chapter 3 of the NRCS Range and Pasture Handbook (https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1043060.pdf).
| July Max Temp (°C) | Jan Min Temp (°C) | Annual Precipitation (mm) | Soil pH | Drainage Class | Soil Salinity (dS/m) | |
| Well-suited | 31 | -12 | 550 | 5.75-7.5 | MWD | 2 |
| Moderately-suited | 33 | -17 | 450 | 5.25-7.75 | SPD-MWD | 6 |
| Marginally-suited | 35 | -22 | 350 | 4.75-8.25 | PD-WD | 8 |
Response functions were developed from these tabular values using Rstudio scripts, with parameters provided for climatic and soil GIS spatial data layers.
Suitability patterns for forage species are caused by different factors in different locations. Low winter temperatures limit the northern range of many species, while low precipitation limits the western range of species in the semi-arid west. Low summer temperatures limit the range of species with increasing elevation while high summer temperatures limit the range in the desert southwest and hot and humid southeast. Soil characteristics (pH, drainage, and salinity) also limit the suitability zones of forage species. However, soil amendments (liming and drainage tiles) can alleviate many of these limitations. Thus, NRCS Soil Survey data should be informed and revised by management mitigations.
Nine maps have been developed; 1) 30-year long-term July maximum temperature 2), 3) 30-year long-term annual precipitation, 4) soil pH, 5) soil drainage, 6) soil salinity, 7) combined climate factors, 8) combined soil factors, and 9) combined climate and soil factors.
High fruit/seed abundance. Grows best in cool conditions (54 to 73°F), moderate to well-drained soils, non-saline conditions (1.5-3 dS/M), and acidic to alkaline soils (pH 5.2-7.0). Optimum production is achieved in areas with little spring frost. Forage yields can reach 7,000 to 10,000 lb/acre under ideal conditions and with proper management and a 120-130 day growing season.
Highly palatable to all livestock classes. High yield potential. Wildlife friendly.
May become invasive. Does not tolerate saturated soil for extended periods of time. Vulnerable to winterkill and overgrazing.
