Seeding Grasses and Forbs

Vegetation Maintenance

Maintaining good vegetation is important to the health of a pasture. Good grass growth can suppress noxious weeds as well as make it difficult for some weeds to establish, resulting in an easier job for you.

Frequently the 50% rule is discussed. In other words take half, leave half. Studies conducted in the 1980’s indicate that ranchers should leave closer to 60% of the above ground vegetation based on the overall mature height of the plant.

The issue is that as more above ground vegetation is removed, the roots are impacted and begin to take up less space in the soil profile. As the above ground forage is reduced, sun light is able to reach more of the soil.

As sun light is able to reach the soil surface and there are no roots growing in the soil in that area, noxious weeds have an easier time of establishing. Top growth removal also impacts how well the roots grow.

For example if 90% of the top growth is taken, the roots stopped growing for 18 days. With only 40 – 50% of top growth removal from the grass, the roots are not greatly impacted and continue to grow.

Another key fact is that the roots account for 70% of the grass plant. Every year, roots generally loose 30% or a third of their mass that naturally dies off. If the grass plant is not stressed, these roots are readily replaced. If the plant is stressed from overgrazing, the plant has a hard time being able to replace these lost roots and store nutrients to survive the dry months and winter.

This is why it is so important to manage the vegetation in your pasture, implement rotational grazing practices and reseed areas that have been depleted.

Reseeding

Reseeding is needed in some cases to enhance an overly grazed pasture or to return a farmed field into a livestock pasture. However, before you reseed evaluate the noxious weeds on the site.

Taking a little extra time to address the weeds on the property, will increase the chance of success your grass seed has at establishing. Remember, the grass seed needs nutrients and moisture to begin to grow.

Weeds that already have a root system will be better able to use the nutrients and moisture, making these items unavailable for the grass seed.

Another important consideration with reseeding is how and when. Typically, if you do not have access to irrigation water a dormant seeding will be done. This means the seeding dates will range from December 1 to April 15. If irrigation is available, you have a more open seeding window.

The two seeding styles are drill seeding and broadcast seeding. Drill seeding places the seed in a firm seed bed, just under the surface. This provides the best seed/soil contact and the highest success rates. With this seeding style you will be using 11 – 14 pounds of pure live seed (pls)/acre. The other option is broadcast seeding. This style applies the seed to the surface of the soil. Typical seeding rates with this operation are 20 to 24 pound pls/acre. Any incorporation of the seed with soil contact that can be done will increase germination success. Be careful not to plant the seed too deep. You are looking at placing the seed within the top ¼ to ½ inch.