Balancing Production and Health of Native Grass Hay Pastures

Native hay meadows are an important part of Oklahoma’s landscape and mostly occur east of I-35. Native hay meadows provide hay for livestock supplementation, habitat for wildlife, and a refuge for biological diversity. Unfortunately, some native hay meadows are mismanaged because of late harvest, cutting more than once in a growing season, and/or cutting too short. As a result, many of these meadows have reduced production potential.

Native hay meadows should be harvested in such a way to sustain long-term productivity and maintain key native grasses, forbs, and legumes. The predominant grasses in native hay meadows include big bluestem, eastern gammagrass, indiangrass, and little bluestem. There are many other native grasses, forbs and legumes that also contribute to hay meadow productivity and diversity. Since native hay meadows are a long-term investment, they should be managed in such a way as to sustain long-term productivity, especially in drought years like we are currently experiencing. 

The most important management practice is utilizing the proper cutting date. In most years, the optimum cutting date will be between late June to early July. Harvesting native hay at this time will achieve a good balance of forage yield and forage quality, while also allowing the native stand to recover over the rest of the year to sustain production for following years. 

The main key to managing any perennial hay field is to maintain a balance between forage yield and forage quality. Time of cutting will be the primary production practice that will determine forage yield and quality. However, it’s important to note that the maximum forage yield and maximum forage quality hardly ever occur at the same time. Hay tonnage will typically peak in late August, while crude protein and digestibility are usually highest in May.

The second most important management practice is proper cutting height. Cutting height can easily be overlooked but can be highly detrimental to the life of the stand. Native grasslands should never be cut shorter than 4 inches. If the growing point of the plant is cut off, then production will be greatly reduced the following year.

Cutting height is also important because most native grass species need time to re-grow and build root carbohydrate reserves. To sustain a native hay meadow, it is recommended to only harvest it for hay once a year. Native grass species grow rapidly through May and June but will exhibit slow regrowth in July (after harvesting hay crops). In addition to this slow regrowth, the regrowth is often less palatable as well. Native species have adapted through natural selection for these traits to ensure grazing animals will not exhaust the root carbohydrates prior to winter dormancy. 

Instead of a second cutting, grazing the regrowth in late summer can be an option. Adequate soil moisture is often the main limiting factor for how fast regrowth occurs. Ideally, grazing shouldn’t be initiated until the native grass reaches 15 – 18 inches in height. To acquire this height sooner, raising the cutting height at haying to 8 inches is recommended.

Field research conducted by Oklahoma State University has shown that forage tonnage can be increased with an application of fertilizer in haying operations. However, it is rarely economical to do so in solely grazing operations. When adequate moisture is available during spring and early summer, 30 – 80 pounds of actual nitrogen fertilizer can increase hay yield and crude protein. Herbicide applications are rarely warranted on native grasslands. If managed properly, there should be a mix of native forbs and legumes that benefit grass production. 

Some small plot studies conducted by OSU have shown that an increase in grass production is possible when broadleaf weeds are controlled with a timely herbicide application. However, production increases varied depending on growing conditions and thickness of grass stand. Previous mismanagement of the pasture often leads to thinner grass stands and more weeds. Herbicides such as 2,4-D and/or dicamba are effective when applications are made to small weeds. As weeds get bigger, more costly herbicides are often needed.

Good management practices include harvesting prior to mid-July, leaving at least 4 inches of stubble, harvesting only once during the growing season, and managing the regrown forage in the dormant season with either fire or grazing.

For more information about harvesting native grasslands for hay, contact the Okmulgee County OSU Extension Office at 918-756-1958. Information can also be found from the OSU fact sheet titled “NREM-2891 Native Hay Meadow Management”.

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