Learn about Managing Pastures
- Some plant species are better than others for animals to graze on.
- Some grow better than others.
- Some are not very nutritious and others can even be poisonous
Managing pastures requires an ability to grow appropriate species in an appropriate way; then control the quantity of grazing for both the feeding needs of the animals and the sustainability of the pasture plants.
There are 8 lessons as follows:
1. Introduction to Pastures
2. The Pasture Plant
- Pasture Improvement
- Choosing a Pasture Mix
- Seed Coating
- Variety Selection
3. Pasture Varieties
- The grass plant
- Growth and development
- Phases of development
- Annual and perennial grasses
- Carbohydrate sinks
- The physiology of grasses
- The structure of grasses
- Growth habits
4. Site Considerations
- Introduction to common pasture grasses
- Identifying grasses
- The Importance of Legumes in Pasture
- Nitrogen Fixation in Legumes
- The Rhizobium bacteria
- Common legumes
- Grasses to Grow With Clovers
5. Establishing New Pastures
- Managing pastures
- Choosing the Correct Site for a Pasture
- Choosing the correct seed mix
- Seed quality
6. Managing Existing Pastures
- Preparation of the land for pasture
- Prepared seedbed
- Direct drilling
- Weed control
- Grazing new pastures
7. Managing Stock on Pasture
- Native Grasses versus Pasture
- Carrying Capacity of Native Grasses
- Stocking Rate of Native Grass Areas
- The Establishment of the Native Grasslands
- The developing grasslands
- How grasslands deteriorate
- Factors promoting succession or retrogression
- Limiting factors and terminal plant communities
- Allogenic Factors
- Autogenic Factors
- Rests To Promote Rapid Growth
- Rests to change the composition of the community
- Rests designed to eliminate or control bush encroachment
- Rests to accumulate grazing material
- Rests to provide out of season fodder
- Physiological aspects
8. Pasture Management Work Tasks
- Factors affecting food intake by animals
- Animal factors
- Feed factors
- Grazing factors
- Grazing behaviour
- Complementary Grazing
- Rank Order of Dominance
- Selective Grazing
- Ruminant Time
- Herd Group Behaviour
- Grazing Time
- Pasture management principles - rest, grazing period, stocking, carrying capacity
- Equal Utilisation or the Removal of the Top Hamper, paddock size, number in herd etc
- Grassland management principles - Split - season Systems, Continuous Light Stocking, One Herd, Four Paddock System, Intensive systems etc
- Horse pastures
- Food trees and shrubs
- Pest and weed control
- Biological control
- Advantages of Biological Methods
- Disadvantages of Biological Methods
- Pasture renovation
- Managing pasture after drought
- Managing pasture after fire
Each lesson ends with an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.
- Determine criteria for selecting appropriate varieties of plants for a pasture.
- Identify characteristics of a pasture plant which are relevant to both making an identification, and to considering its value as a pasture species.
- Evaluate the potential of given sites for pasture development programs
- Explain the procedures used in managing the establishment of pasture.
- Explain the techniques used in managing pasture which is already been established
- Assess the commercial and nutritional value of pasture species in the context of farm animal feed, and determine appropriate ways of managing stock.
- Develop an appropriate work program for the management of a pasture by a farmer.
WHAT THE COURSE COVERS
Here are just some of the things you will be doing:
- Prepare a catalogued resource collection of items including pamphlets, brochures and contact addresses for information relevant to pasture varieties.
- List factors that affect the choice of seed mix for a pasture.
- Categorise different pasture seed mixes according to application, detailing the components of each mix together, commenting on appropriate applications for that mix.
- Explain the benefits of seed coating for pasture establishment.
- Label parts of a grass plants on unlabeled diagrams
- Distinguish between different clover and medic species using illustrations
- List different pasture plant varieties suited to your locality, including:
- other fodder plants
- Identify different species of plants growing in an established pasture in your locality, by labelling a pressed specimen of each.
- Submit samples of seeds you identified
- What type of pasture is inoculated, and why?
- Give and explain one example of why a dairy cow might perform differently when grazed on different types of pasture species?
- Compare samples of different pasture seed mixes.
- List different species which would be appropriate to grow in each of the following situations:
- Dairy cattle on fertile, moist soil in your locality.
- Beef steers on poorer soils in your region.
- Horses for a horse riding school in your locality.
- List factors affecting the suitability of a site for pasture.
- Assess climatic and edaphic data for a specific pasture site, including:
- soil type
- Compare the appropriateness of different soil cultivation techniques for pasture establishment on a specified site in your locality.
- Explain weed control methods during pasture establishment on a specified site.
- Explain grazing practices appropriate to new pasture on a specified site.
- Establish production targets for a specified pasture, explaining how those targets are determined.
- Select suitable machinery for pasture management including establishment and harvest, explaining the selection.
- Explain the steps involved in preparation of a specified area land for sowing pasture.
- Write a plan for the establishment of new pasture on a specified site, which lists all important tasks in chronological order.
- Explain factors causing change in the nature of established pasture.
- Compare improved pasture with native pasture, with respect to:
- species present
- maintenance requirements
- List characteristics of different types of pasture, including:
- Determine sustainable stocking rates of a specified type of animal for different pastures. Specify the pastures and the animals.
- Analyse the food value of different pastures.
- Compare the grazing behaviour of different farm animals.
- Define the concept of palatability of a specific pasture
- Determine grazing capacity of a specified paddock.
Specify the crop and all other variables.
- Evaluate the production performance of two different specified pastures.
- Identify different weeds that are significant problems in pasture
- Explain methods of weed control in a specific established pasture.
- Explain the affect of fire on a specific pasture.
- Explain the affect of different soil management practices on pasture, including:
- pest control
- Quantify materials and supply requirements for pasture management.
- List facilities required for the handling and storage of materials and supplies.
- List minimum machinery required for the management of a specified site.
- Develop management plan for pasture in a specified situation, including a program of tasks to be carried out over a 12 month period.
- Explain industry research techniques and develop a conclusion.
USING RYE GRASSES IN A PASTURE
Rye grass (Lolium species) are considered one of the more nutritious grasses for grazing livestock. There are many different types of rye-grass cultivars but they can be divided into three broad types:
- Annual Rye Grasses: These grow, reproduce and die within a year. They are sensitive to the length of day and night and flower when there are sufficient daylight hours. Some cultivars can flower, seed and die within three to four months if conditions are right.
- Perennial Rye Grasses: These are permanent or long lasting. They need cold to induce flowering. Farmers often face a severe shortage of grazing over two periods of the year. The wide choice of rye-grass cultivars means that farmers can grow different varieties for the spring and autumn\winter gap. An autumn planted perennial will give a good spring flush while a spring planted annual will provide lush autumn to winter grazing.
- Biennials (Hybrid): Research has lead to the development of a biennial rye-grass. Crossing an annual and a perennial cultivar to form a hybrid did this. The cultivar is called Bison and can be planted in spring or autumn. Bison is vigorous, gives high yields and is resistant to cold, heat and disease.
Annual ryegrass (Lolium rigidum)
This ryegrass is thought to have originated from seed brought from Europe. Vigorous growth in low rainfall areas gives this ryegrass its main value. It produces a large volume of palatable growth at all stages of its growth and makes excellent hay or silage. It germinates after autumn and grows through winter and spring before flowering and setting seed in mid spring. It regenerates by seed and will persist indefinitely. Seedlings are very competitive. This species has a heavy, extensive, fibrous root system.
Annual ryegrass is adapted to areas with rainfall of 350 – 600mm (even lower in some areas). Leaves are narrow and shiny on the under surface and stems have a reddish tinge at the base. Seed borne on a single spike and are flatter and wider than other ryegrasses. Seeds can survive in the soil for a year.
Annual Ryegrass is recommended for land that is not tilled frequently. It is relatively salt tolerant. It grows best on soils of high fertility or those where nitrogen and phosphorus have been increased with legumes and superphosphate. Sowing rate for this grass in mixtures is commonly 3.4 5.6 kg/ha.
Annual ryegrass is suitable as a cover crop in grass waterways or riparian areas subject to flooding as it tolerates wet soils and temporary flooding. It can also be grown under conditions where other cover crops fail. It establishes quickly and grows throughout the winter. It is an excellent choice for soil protection and weed suppression.
Wimmera Annual Ryegrass is valued in low rainfall areas with a minimum of 305 mm per year. There is a danger of ryegrass toxicity, especially in Western Australia (a nervous disorder of sheep, cattle and sometimes horses. It results when these animals eat seed heads infected with a nematode and a bacterium).
Merredin Annual Ryegrass has a shorter growing season than Wimmera and tolerates low rainfall and shorter growing seasons.
Perennial Ryegrass (Lolium perenne)
This is a hardy, upright growing grass that recuperates well. During the growing season, Perennial Ryegrass forms a large leafy herb. It requires a fertile soil of medium texture but does not like loose soils that dry out quickly. Generous fertilizer produces the best results.
Perennial ryegrass has been selected for improvement in New Zealand and Australia. There is now a range of cultivars that differ significantly in maturity, summer dormancy and resistance to moisture stress and diseases. These cultivars are densely tufted with dark green leaves which are shiny on the under surface. The flowering stems are erect spikes bearing straw-coloured seeds about 6mm long.
Seeds are best sown on clean, fertile loamy soil. Provided they receive adequate rainfall, seeds are easy to establish and will grow vigorously. The recommended sowing rate of 11.2 kg/ha is best in autumn, but spring sowing is possible in districts with more than 760 mm rainfall per annum. In low rainfall areas that have high evaporation rates, drill the seeds about 12 mm deep.
Perennial Ryegrass handles traffic well and heavy grazing. It is incredibly resistant to cold weather and frost, and grows from early autumn – winter. They flower in spring and early summer. Different cultivars have different lengths of summer dormancy; therefore summer growth is determined by this.
Perennial ryegrasses can be sown alone but more often grass mixtures containing perennial ryegrass, cocksfoot and tall fescue, with appropriate legumes are preferred. Ryegrass seedlings are vigorous; therefore do not sow species with less vigorous seedlings in the seed mix (e.g. phalaris). Perennial ryegrass is susceptible to rust disease (Puccinia coronata) during warm humid weather usually in autumn.
It is used widely on sports grounds, for ornamental and functional applications. Probably the most commonly used turf. Perennial ryegrass makes up the most productive pastures in Britain, Ireland, Europe, New Zealand, and the cooler regions of North America and Australia. Nutritive value is very high and they are very palatable to sheep and cattle.
Other Cultivars include:
Victoria Perennial Ryegrass (cultivar)
This natural selection was developed in Victoria, Australia, and it requires an approximate minimum of 550 mm rainfall a year. It is better adapted to the hot, dry summers of western Victoria. It is susceptible to crown rust and Barley yellow dwarf luteovirus. It is less productive than other cultivars in most situations. Victorian Ryegrass grows well in autumn but slows dramatically in winter. As the weather warms, growth recommences till part dormancy during dry summers.
Grasslands Ruanui Perennial Ryegrass (cultivar)
Developed in New Zealand, this ryegrass grows similar in pattern to Victorian Ryegrass. It is adapted to high fertility soils where summer temperatures are mild and annual rainfall exceeds 635 mm. It is most productive in spring and early summer.
Medea Perennial Ryegrass (cultivar)
Developed in South Australia, Medea is more drought resistant and has a different growing season to the above mentioned ryegrasses. It is more active during late autumn, winter and early spring but semi dormant through summer. It does not respond to summer rainfalls.
Kangaroo Valley Perennial Ryegrass (cultivar)
This variety was developed by natural selection in the Kangaroo Valley of New South Wales, Australia. It has evolved the following characteristics: early maturity, excellent persistence in a wide range of situations, drought tolerance, leaf rust resistance and good late winter-early spring forage production. It seems to be less drought tolerant than Victorian Perennial Ryegrass.
Certified seed of this cultivar can only be produced in the area where it evolved – ensure the range of genetic material.
Italian Ryegrass (Lolium multiflorum)
Winter growth makes this ryegrass very valuable, as it can be twice that of perennial ryegrass. It requires high fertile soils with at least 760 mm of rainfall. It even grows well under very wet conditions. Fertile soils are required for best results. Otherwise it can be top dressed with nitrogenous fertilisers. It is not suited to highly acidic soils. It is extremely frost resistant. If sown in autumn this grass has excellent winter growth and rapid growth in spring before flowering in summer.
Italian Ryegrass seedlings are easier to establish and more vigorous than Perennial Ryegrass. They are taller, more robust, and the seeds are larger and have bristles or awns. It is often included in permanent pasture mixes to provide feed while other slower species become established. However due to its vigorous growth it can smother other grasses, such as clover, therefore it should be grazed in its first year otherwise a poor pasture may result.
Recommended sowing rates are 11.2 kg/ha where it is the only grass or much lower rates if it is included in a mixture.
There are many forms of Italian ryegrass. A wide range of cultivars have been developed and vary with their susceptibility to rust; crown rust being the most serious, followed by stem rust. Widely used for temporary pastures (in crop rotations) and as a high quality hay crop around the world. Italian ryegrass may also be included in mixtures with perennial ryegrass and cocksfoot to give increased winter feed in the first year. Annual or short-lived legumes are also a good mixture.
Hybrid Ryegrass (Lolium perenne x L. multiflorum)
Natural hybrids between perennial and Italian ryegrasses do occur. In comparison with perennial ryegrass, a hybrid has a more extended growing season and higher production. Persistence and winter-hardiness are less than perennial ryegrass but better than Italian ryegrass.
These hybrids need high rainfall, a temperate climate and fertile soils. They may be used as short-term pastures with a mixture of red clover or included in pastures of perennial ryegrass and cocksfoot for high winter yield. These hybrids are intermediate in size between the perennial and Italian ryegrasses. Seed size is larger than perennial ryegrass but smaller than Italian.