Establishment of forage plants is more difficult than many other crops because some require more than one year to establish and forage seeds are often small and must be placed in shallow depths where soil moisture, pH, herbicide residue, and temperature show the most variation.
Successful establishment of adapted grasses and legumes is the foundation of developing sustainable forage-livestock systems.
Seeding failures are expensive and upset plans for grazing and forage utilization. Successful establishment results in dense stands that persist, leading to higher yields, good return on investment, and an increase of desired species.
Advantages and Disadvantages of Pasture Establishment
Whether a producer is part-time or commercial, good pastures are profitable. They provide an economical source of livestock feed, reduce labor requirements, build soil tilth and fertility, reduce erosion, and reduce invasions of noxious and poisonous weeds.
When obtaining new land that will be used for forage production, especially pasture, a forage-livestock producer is encouraged to use the first year carefully. Fertilizing wisely and managing the pasture strategically enables the producer to learn much about what the land is capable of producing. Investing in establishing a pasture from scratch may sound appealing, but without a change in management, the pasture will revert to the previous plant composition in a few years, becoming a waste of money, time, and labor. Well established and managed perennial pastures can produce effectively for five to ten years or more.
To establish a productive forage stand, a forage-livestock producer must understand the fundamentals of successful establishment. "Starting from scratch" means soil preparation, seeding, and producing forage.
Removing whatever is currently growing takes careful thought and preparation. One factor that must be considered is possible erosion during the time the ground is prepared for planting but not producing. Typically, removing existing plants means using a herbicide. Liming, fertilization, further weed control and proper seeding need to be carefully planned.
Successful pasture establishment has three essential building blocks: good soil conditions, a properly adapted species, and good weather. Choose a species that is well adapted to the soil pH, the expected climate conditions (winter hardiness), realistic drought or flood tolerance, and well suited to the intended use and livestock type.
Soil pH and Fertility
Once a forage species has been carefully chosen, adjust soil conditions to match species requirements. That includes soil fertility (having adequate levels of macro- and micronutrients, and soil aeration) and pH. There are 16 essential plant nutrients. Take a soil sample to determine what is needed to improve soil fertility.
Successful establishment of a pasture is greatly determined by weather. The temperature extremes, expected precipitation, and flooding possibilities need to be considered. Many weather conditions are often out of your control but establishment planning should utilize as much weather information as possible. Weather patterns in many areas indicate that spring and fall are the most moderate seasons and establishment often occurs then. However, in areas where spring is very wet and unpredictable, like the northwest, establishment often occurs in the fall. Since a moist soil will be beneficial, certain weather conditions can sometimes be very wisely used.
Overall, establishing a pasture can mean a high-quality forage that is well matched to the intended livestock and use. A producer can carefully plan what is best for his operation. If well planned and executed, establishing a forage stand can mean years of high-quality feed. This requires careful planning, usually a year in advance, and specific steps in preparation.
The steps to properly prepare a seedbed are based on seed germination requirements. A key is good seed-to-soil contact. This ensures that the seed will absorb soil moisture and utilize soil nutrients. This requires a firm seedbed and for smaller seeds will require a more finely pulverized soil.
The characteristics of a good seedbed are: uniformly firm soil to depth of 5 inches (12.7 centimeters), adequate soil moisture, and weed-free. Each of these characteristics help the seed to have the best chance to germinate and flourish. A seedbed that is weed-free allows the desired crop to grow without the competition for nutrients, space, and sunlight. Adequate soil moisture triggers the enzymatic changes needed to grow. The seedbed needs to be firm because that indicates that moisture down in the soil can be brought up for seed germination. Fluffy soil at the surface usually means too much air is trapped in the soil and that will dry out the conditions and seeds will not germinate.
The steps to obtaining a good seedbed include: 1) plowing the soil to 5 inches (12.7 centimeters) in depth; 2) using a disk twice, with the second trip cutting perpendicularly to the first cut. When plowing, weed seeds are brought closer to the surface and with closer contact with the sunlight and soil moisture they will germinate soon thereafter. After plowing and disking, allow the weed seeds to germinate and use herbicides to eradicate them. Then, the soil is disked again to turn under the dead plant material to promote seed to soil contact.
Using high quality seed is a fundamental concept. What determines the quality of seed may not be so obvious. When purchasing certified seed, tags will state the percentage of germination and purity. This allows the producer calculate a Pure Live Seed percentage for planting. Pure Live Seed is calculated by multiplying Germination Percentage by Purity Percentage. To plant 15 lbs/acre of PLS, divide the intended seeding rate by the PLS percentage.
There are several seed treatments that are used to increase seed germination and vigorous seedling growth:
pesticide additions (fungicide, herbicide)
Scarification is a physical abrasion of the seed coat to allow penetration of moisture needed to initiate germination. Legumes often have hard seed coats which enable them to survive a long time within the soil. Scarifying the seeds will encourage germination in the year of planting.
Cold storage is a treatment that breaks the dormancy of a seed.
Inoculation is recommended when planting most legumes to ensure a large number of effective rhizobia in the rhizosphere of the germination seedling. Nitrogen fixation by legumes is essential to vigorous legume growth. Legumes fix nitrogen only if infected with rhizobia bacteria. These bacteria attach to legume roots producing nodules. The number, size, and internal color of nodules are good indicators of the amount of nitrogen fixation occurring. A white-colored nodule is not fixing nitrogen. This is natural in winter but not in the growing season. A blood-red nodule is producing nitrogen.
Different legumes require different strains of bacteria inoculant, so a producer cannot assume that legumes will find what they need in the soil. White clover, alfalfa, and trefoils all are common legumes but each requires a different strain of bacteria inoculant. Use a commercially prepared strain of inoculant designed for the species planted. Inoculating your legume seeds is not difficult but can be time-consuming and messy. Thoroughly and carefully inoculate the seed and follow other careful management practices to insure viable infection of the bacteria on the newly germinated root hairs. Or you may purchase inoculated seed.
Pesticides are occasionally recommended for diseases or insects, and herbicides have been used as a seed treatment to deter competitive weed growth.
Seed sold in feed and seed stores labeled "Pasture Mix" should be carefully considered. Often these mixes contain a high percentage of annual ryegrass which may look promising very quickly but will not help to establish a long-term pasture. Read the species included in the contents of mixtures and look for species that will perform according to your long-range plan.
Methods and Timing of Seeding
There are many commonly used methods for seeding a forage. Each method is used with planting time considerations. These considerations include:
Is there adequate soil moisture?
Is there adequate remaining growing season?
Are temperatures cool enough for seedling development?
What potential weeds are likely?
What other farm activities are pressing?
Cool-season species should be planted early in the spring so that there is enough time for seedlings to develop before the summer brings hot, dry weather. They should also be planted early enough in the fall to be strong enough to survive frost and winter stresses. In planting warm-season species, avoid planting seeds in soil too moist and temperatures too low where seeds may rot before germination.
Recommended seeding rate is often a controversial topic. A wide variance appears in seeding rate information, charts, and guides. This is because every location has different environmental factors and forages are grown over a vast variety of locations. Seeding rates also differ between forage and seed crop applications. Become familiar with the range in seeding rates in your area. Remember that seeds have a high mortality rate. Some predict that only about one/third of the seed sown will reproduce seedlings and only half of those survive the first year. The main objective is to seed enough for good forage production. Seed is a minor expense, and high seeding rates may prove to reduce the weeds.
Consider the following:
the condition of the seedbed
the expected germination percentage
the mixture of species if a mixture is used
the method of seeding.
There are several methods for putting seed into the ground. Some require specific requirements to be successful. Others are reliable in a wide range of conditions. Many seeding methods rely on removal of existing plant growth. This can be done be tilling (plowing) or by applying herbicides. Tillage also turns under many of the weed seeds near the surface and brings up other materials that are desirable such as lime and minerals. Tillage will cause some soil moisture loss from evaporation and leave the soil less anchored, which may lead to erosion. Allowing some top residue like clippings, twigs, and mulch has been found to be beneficial for emerging seedlings. Tillage will also bring new weed seeds to the surface, and that should be expected in the overall plan.
Since tillage has some drawbacks and requires machinery, time, and expense, so some forage producers use no-till establishment. Existing plants are killed with herbicides and seeding can still be done in a variety of ways. Young plants sown with no-till practices may require more care in terms of fertility, pH, and water.
The main types of seeding methods are:
grain drill with grass seed attachment,
band seeder which adds fertilizer below and to the side of the seed,
The goal is to place the seed at a uniformly shallow depth (1/4 " to 3/8"); place fertilizer near the seed and firm the soil around the seed. Most machinery will place the seed and press the soil, but in broadcast seeding the seed is distributed and rolling is an additional step. Rolling can be done by machine, or by dragging something heavy (board, light chain, or brush) over the seeded area, or allowing livestock to trample the seed into the ground.
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