AGR-26
Renovate means to renew and improve. This publication discusses managing a pasture or hay field that has become less productive and "renewing" it so that it will become more productive. In Kentucky, this usually means adding lime and fertilizer, controlling weeds and insects, and planting a legume such as red clover. The primary benefits come as a result of getting legumes established in grass-dominated fields.
Adding legumes to hay and pasture fields brings at least four benefits:
The total yield of forage per acre is increased. For example, a study conducted at Lexington compared renovating a fescue pasture using red clover to fertilizing the grass with nitrogen (Table 1). In this study, red clover growing with fescue produced higher yields than fescue fertilized with up to 180 lb N/ac.
| Table 1. Dry Matter Yields of Fescue-Clovervs. Fescue-Nitrogen--Lexington, 1978, 2 Yr. Average | |
| Treatments | Yields, lb/ac |
| Fescue-Red Clover | |
| 6 lb Seed/ac | 11,100 |
| Fescue + Nitrogen | |
| 0 lb/ac | 3,900 |
| 90 lb/ac | 6,700 |
| 180 lb/ac | 9,900 |
| Taylor, T.H., et al. University of Kentucky | |
Adding legumes to grass fields improves forage quality over grass alone. This added quality includes increases in palatability, intake, digestibility, and nutrient content. The result is improved animal performance. Research has shown that legumes improve animal growth rates, reproductive efficiency, and milk production. The three studies summarized in Table 2 show improved growth rates of beef cows, calves, and steers when legumes are used. The study reported in Table 3 shows increased growth rates of beef steers grazing a fescue-ladino clover pasture. It also shows higher gains per acre as a result of improved forage quality and higher yields.
| Table 2. Animal Performance on Grass vs. Legume-Grass Mixtures | ||||
| Species | Length of Trials (Yrs) | Gain/Head (lb/day) | Animal Class | State |
| Tall Fescue | 3 | 0.12 | Cows | IN |
| Tall Fescue + Red & Ladino Clover | 0.74 | |||
| Tall Fescue | 3 | 1.30 | Calves | IN |
| Tall Fescue + Red & Ladino Clover | 1.80 | |||
| Orchardgrass | 10 | 1.07 | Steers | VA |
| Orchardgrass + Ladino Clover | 1.28 | |||
| Table 3. Av. Daily Gain and Gains/Acre of Steers Grazing Tall Fescue & Tall Fescue-Clover Pastures | |||
| Pastures | Daily Gain (lb/steer) | Total Gains | |
| lb/steer | lb/ac | ||
| Fescue + Ladino Clover | 1.53 | 307 | 582 |
| Fescue + 150 lb N/ac | 1.06 | 203 | 374 |
| Hoveland, C.S., et al. 1981. Bulletin 530. Auburn, AL | |||
High quality feed is important in getting beef cows re-bred after calving. Research conducted in Illinois and Indiana (Table 4) compared conception rates of cows grazing tall fescue pastures with and without legumes. In both tests, the cows grazing legume-grass pastures had much higher conception rates.
| Table 4. Conception Rates on Grass vs. Grass-Legume Pastures | ||
| Species | Conception Rate % | State |
| Tall Fescue | 75 | IL |
| Tall Fescue + Legume | 89 | |
| Tall Fescue | 72 | IN |
| Tall Fescue + Clover | 92 | |
Legumes get their nitrogen needs from symbiotic bacteria that live in "knots" (nodules) on their roots. These bacteria are added when legume seed is inoculated. This "fixed" nitrogen provides the nitrogen needed by the legumes and also by grasses growing with them. Different legumes are able to "fix" different amounts of nitrogen (Table 5). Alfalfa usually fixes the most, while annual lespedeza is on the low side with about 75 pounds.
| Table 5. Value and Amount of Nitrogen Fixed by Different Legumes | ||
| Crop | Lb/ac/Yr | Value of Nitrogen1 |
| Alfalfa | 200 - 300 | $ 50 - 75 |
| Red Clover | 100 - 200 | 25 - 50 |
| Ladino Clover | 100 - 150 | 25 - 37.50 |
| Vetch, Lespedeza and Other Annual Forage Legumes | 75 - 150 | 18.75 - 37.50 |
| 1Fertilizer nitrogen valued at $0.25/lb | ||
The value of the nitrogen fixed by legumes depends on the cost of nitrogen fertilizer. The values in the right column of Table 5 are based on nitrogen priced at 25 cents/lb or ammonium nitrate fertilizer at $170/ton.
Most of the growth of cool-season grasses occurs during the spring and fall. Legumes make more growth during the summer months than cool-season grasses. Growing grasses and legumes together improves the seasonal distribution of forages and provides more growth during summer.
Follow these six important steps when renovating grass fields with legumes:
Step 1. Have the soil tested and apply the needed lime and fertilizer. Legumes need a higher soil pH and fertility level than grasses. However, DO NOT use nitrogen. Added nitrogen stimulates grasses, which increase competition with the legumes.
Step 2. Reduce the vegetative cover on the soil. This is best done by heavy grazing in late fall and early winter. Removing the excess grass cover will make it easier to get the legume seed in contact with the soil.
Step 3. Select the legumes to be used. This will depend on the soil and the planned use of the forage. For hay, alfalfa or red clover is usually best. For both hay and grazing, a combination of red clover and ladino clover works well. Ladino, red clover, and/or annual lespedeza work well in pastures.
Step 4. Use the right kind and amount of seed. Select varieties that perform well in your area. The only way to be sure of what you're planting is to use certified seed. Table 6 provides some seeding rate guidelines. Also be sure to use the right kind of high quality inoculant mixed with the seed just before planting. Use a sticking agent to be sure that the inoculant sticks to the seed.
| Table 6. Legume Seeding Rates for Renovating Grass Fields | ||
| Mixture Number | Legume(s) | Seeding Rates* lb/ac |
| 1 | White Clover | 1 - 3 |
| 2 | Red Clover | 6 - 12 |
| 3 | Annual Lespedeza | 15 - 25 |
| 4 | Alfalfa | 12 - 20 |
| 5 | White Clover and Red Clover | 1 - 2 4 - 6 |
| 6 | Alfalfa and Ladino Clover | 8 - 10 ½ - 1 |
| 7 | Birdsfoot Trefoil | 6 - 8 |
| *If seeding is done at the proper time and under good conditions, the lower rates can be used. The higher rates may be needed for broadcast seedings or when conditions are not the best. | ||
Step 5. Plant the seed so that it makes good contact with the soil. There are several ways to do this. One of the best ways for most farmers is to use a disk, field cultivator, or field tiller. Disturb 40 to 60 percent of the sod for planting clovers. For alfalfa seeding, almost all of the sod should be torn up (loosened from the soil). Tillage helps control the grass growth and exposes the soil so the legumes have a better chance to germinate and grow. Broadcast the seed and pack the soil with a corrugated roller.
Another method is to use a no-till renovation seeder. These do a good job of placing the seed in the soil, but they don't reduce the competition from the grass.
A simple, but effective method is to broadcast the legume seed on the soil surface in late winter (Feb. 15 to March 15). As the soil freezes and thaws, the seeds become covered. This method does not work well with alfalfa.
Herbicides can be used to kill or suppress some of the grass and help control competition. Follow the label directions for rates and grazing restrictions when herbicides are used.
Step 6. Control grass and weed competition. This step is one of the most critical ones. Many attempts at renovation have failed simply because the grass was allowed to grow and reduce the light, nutrients, and water available to the young legume plants. The grass must be kept short by grazing or mowing until the new legume plants are 3 to 4 inches tall. Stop grazing if the animals begin biting off the young legume leaves. Grazing and mowing should be stopped for several weeks to allow the legumes to become well established. After this, the field should be mowed or grazed on a schedule that will help keep the particular legumes used in good condition. A rotational grazing system helps keep legumes in the stand longer.
More detailed information on many of the recommendations discussed in this publication are available from the University of Kentucky College of Agriculture Cooperative Extension Service. The following list may be helpful: