To provide maximum amounts of quality forage, it is important to include both cool and warm season grasses in a forage program. Both warm season and cool season forages will be included in the demonstration area.
Warm season plants grow primarily from June through early September. Known as C4 plants, these plants are better adapted to hot, dry weather due to the pathway used to capture carbon dioxide during photosynthesis. Cool season forages, C3 plants, use a different pathway which provides greater tolerance for cold weather, growing best in the spring and fall when soil and air temperatures are cooler.
Comparing C-3 and C-4 plants in Tennessee (generally speaking):
| Characteristic | C-3 Plants (Cool Season) | C-4 Plants (Warm Season) |
|---|---|---|
| Length of Growing Season (In Tennessee) | X | |
| Nutrient Quality | X | |
| Less water required | X | |
| Performs better in heat | X | |
| Performs better in cool temps | X |
Fall-Winter 2023-2024
A cover crop has been planted over the entire demonstration area. The winter cover crop helps to protect the area and will also help to prevent soil erosion. Cover crops are temporary, or annual crops which serve as beneficial “place holders” until the perennial crop is planted at the proper time. Crimson clover, a legume species, was used because of the legume’s ability to capture atmospheric nitrogen and convert it to soil nitrogen. This reduces the amount of nitrogen fertilizer needed for the forages. Legume species can fix 50 to 150 pounds per acre of nitrogen!
The crimson clover was planted October 10th, but due to the drought we have been experiencing, germination was slow. Whenever a seed is placed in the ground, a race occurs. It’s interesting to see what seeds germinate first. Will it be the seed that was planted? Or will it be other seed that has been existing in the soil “seedbank” for possibly years?
Mid-January 2024 Update:
In this particular germination race it’s apparent that in portions of the forage plot area, crimson clover lost the race. You will see several cool season annual weeds. Some of them are: hairy bittercress, purple dead nettle, common chickweed, and field madder. A perennial species you can also observe is buckhorn (or ribwort) plantain. This entire planting will be replaced in the spring with forage variety plots.
Mid-April 2024 Update:
Oh, the benefits of cover crops! Last fall crimson clover was planted and had a rather slow start due to the extremely dry conditions we were experiencing. Take another look, and you will see that eventually it rained and eventually the crimson clover germinated! We have a beautiful stand of the plant—and it has been a real pleasure to observe the pollinators taking advantage of the early spring food supply. We’ve also observed walkers (of the human kind) taking advantage of the beautiful backdrop to photograph pets and children!
Very soon we will be “terminating” this annual clover (which would have died soon, anyway) to make room for perennial warm season forages. These forages will be a living laboratory to determine nutrient value, tonnage produced, and test management strategies of various forages.
Remember, forage crops are crops which animals eat. The collected information will be available for all to see and provide a valuable tool to inform forage crop decisions for agricultural producers. This demonstration area provides real-time, local data to inform farmer decisions so that they can better feed livestock in their care. The clover did its job well—providing early spring food for pollinators and contributing nitrogen to the soil.
Stay tuned for details concerning what is planted next…..
Mid to Late-May 2024 Update:
All warm season plots are planted. Colored Forage Plots Map below.
Planted May 16: Laredo (bermudagrass), Cheyenne II (bermudagrass), Red River Crabgrass, Dessie Teff, and Mojo crabgrass. Seeding method was broadcasted and then cultipacked.
Planted May 20: Ray’s Crazy Mix which is a mixture of Cowpea, BMR Sorghum Sudan, Daikon Radish, Hybrid Pearl Millet, Peredovik Sunflower, and Hybrid Brassica. This summer cover crop is in the area that will be renovated to plant cool season forage plots in the fall. This was planted with a no-till drill.
Planted May 28: AU Grazer (improved variety of sericea lespedeza) and Kobe, a Korean lespedeza. AU Grazer is a perennial forage, Korean lespedeza is an annual. Both lespedezas required inoculation prior to planting. Seeding method was broadcasting and then using the cultipacker over the top. These plots have some slope. During this period of time, we have received several heavy rain events with resulting water flowing over the plots. As a result, some seed may have washed with the water; time will tell just how much and where it went.
July 17th Update:
This summer’s hot, dry weather is providing the opportunity to showcase the importance of incorporating warm season forages into the overall forage plan. Why? Because warm season forages are designed to grow in hot and dry weather (see above information regarding C3 and C4 forages). There is variation among warm season options regarding water use efficiency; but as a general rule, warm season forages are more efficient users of water than cool season forages. In other words, they can perform with less water than their cool season counterparts.
Since June 1, we have received only 3.22 inches of rain on the plots. The crabgrass and teff grass plots were harvested July 1 and by next week should be ready to harvest again. The warm season perennials, slower to germinate and establish than the annuals (and even slower due to poor rainfall) are not yet ready for the first harvest.
Crabgrass Forage Plots
Lest we get carried away with water efficiency and think warm season options are all we need, remember that warm season forages grow only during the warmer (think summer) months of the year. In Tennessee, cool season forages provide the longest growing season(s) with a huge growth period in the spring and a second smaller growth period again in the fall.
To maximize forage grazing days in Tennessee, both cool and warm season forages are required.