Avena sativa L.


Oats are a small grain, cool-season species used both as a grain and forage. It is the least winter hardy species of the small grains. It is typically planted in the spring as a summer annual. It is used primarily as silage and hay, but sometimes as pasture. Commonly used in companion seedings with legumes. 


Species Selection Characteristics

Annual Precipitation (inches): 
12 to 16
16 to 20
20 to 24
24 to 28
28 to 32
32 to 36
36 to 40
40 to 50
50 to 60
Soil pH Tolerance: 
Strongly acid, 5.1–7.3
Moderately acid, 5.6–7.3
Moderately acid to moderately alkaline, 5.6–8.4
Slightly acid to moderately alkaline, 6.1–8.4
Near neutral, 6.1–7.3
Soil Drainage Tolerance: 
moderately well drained
well drained
Flooding Tolerance: 
3-6 days
Soil Salinity Tolerance: 
Moderately tolerant, 3–6 dS/m

Identification Characteristics


Growth Habit and Stand Life

Growth habit: Upright bunch growth

Life Cycle: 
Winter annual

Climate and Soil Suitability Zones

Climate Tolerances: 

Oat is a cool-season annual grass. It is more winter-sensitive than other small grains. Winterkills in Hardiness Zone 6 and colder and much of Zone 7.

Temperature: Optimum growth range is 68°F to 70°F. Growth substantially reduced from 82°F to 86°F and higher.

Precipitation: 18-53 inches annually

Soil Tolerances: 

pH: Strongly acidic to moderately alkaline (5.1-8.4)

Drainage: WD-MWD

Salinity: Moderately tolerant, 3-6 dS/m

Flood tolerance: Brief, 3-6 days only

Suitability Maps

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.


Oat cultivars are classified on the basis of maturity rating (early, mid, or late-season) and projected use (grain or forage type). A mid-season cultivar will mature more rapidly than a very late-season cultivar, regardless of growing season (spring or fall), or planting date within season. Two other characteristics of oat cultivars also are important. First, cultivars selected specifically for production of forage generally exhibit much slower maturation characteristics than grain-type cultivars. Secondly, oats have a long-day photoperiod requirement for flowering that is disrupted by a late-summer planting date. As a result, the maturation rate for all cultivars is generally much slower in the fall, and differences between cultivars of diverse maturity classes tend to be more separated.

Management Level Required

Suitable Management Level: 

Quality and Antiquality Factors

Quality Factors: 

Forage yield and feeding value of the harvested crop change as the oat plant matures through its growth stages. When harvested for silage or hay, very high quality forage is obtained when it is harvested in the boot stage, with higher yields when harvested later (mild or dough stage of the grain).

Anti-quality Factors: 

Nitrate toxicity can occur with oats when over-fertilized with nitrogen (either commercial fertilizer or manure) and when drought-stressed. Ensiling reduces the nitrate level 40 to 60 percent. Have suspected forage tested before feeding to cattle. Dilute suspected forage by mixing with low nitrate forages and/or energy feeds such as molasses or corn.

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