GRASSLAND MANAGEMENT

GRASSLAND MANAGEMENT

The term grassland refers to those areas where grasses are the main component of the vegetation.

Pastures are areas of grass suitable for grazing animals.

Types of pastures

Natural pastures

These are open areas with dense cover of native grasses and associated herbaceous plant species. Trees and shrubs may be present in big clusters or may be scattered. The forage plants found there are indigenous and well adapted to the soil and environmental conditions.

Advantages of natural pastures

1. Forage plants found in natural pastures are well adapted, thus can persist under poor management.

2. They contain a wide variety of forage plants; i.e., grasses, legumes and other brousable species from which livestock can graze.

3. They are found in areas that are difficult to cultivate. Such land can be used for grazing livestock as an alternative.

4. They support a large population of local livestock species, like goats,sheep and cattle.

5. They are cheap to maintain since they do not require a lot of care.

6. If improvement is to be done, fewer inputs ( planting materials, fertilizers) are required.

Disadvantages of natural pastures

1. They are less productive in terms of herbage yield and nutritive value. Therefore, animal production that is based on natural pastures is so low.

2. The grasses mature very fast becoming stemmy and coarse, with the resultant drop in palatability and nutritive value.

3. Natural pastures are usually communally used and hence overgrazed.

4. Due to poor management of natural pastures, livestock diseases spread very fast from herd to herd.

Improved pastures

These are grasses originally found on piece of land but modified by man by weeding, fertilization and mixing with other grasses and legumes.

Temporary pastures / leys

Leys are pastures grown in rotation with arable crops. The practice of growing pastures in rotation with arable crops is referred to as ley farming.

Advantages of ley farming

1. It provides herbage for animals/ cheap feed to livestock.

2. Leguminous leys add nitrogen to the soil.

3. Improves soil structure by additional of organic matter and this binds soil particles in aggregate particles.

4. It checks soil erosion since its roots bind the soil particles together.

5. Helps in disease and pests control. i.e creates a break in disease and pests cycles.

6. Helps in nutrient circulation/nutrients from deeper layers are brought to the surface by grass leys.

Characteristics of a good pasture plant

1. Should contain adequate nutrients for animals.

2. Should be resistant to pests and diseases.

3. Should be resistant to grazing.

4. Should be resistant to drought.

5. Should establish and grow fast or should regenerate quickly after grazing and toping

6. high yielding with high leaf to stem ratio.

7. Should produce leafy materials for a long period.

Establishment and management of pastures.

Procedure of establishing a sown pasture.

1. Trees are felled, bushes slashed, stumps uprooted and anthills leveled.
2. The seedbed should be ploughed and rested for 3-4 weeks to allow the vegetation to decompose. Plough again using a disc harrow so as to make the seedbed fine. Sown grasses and legumes require a seed that is fine .
3. Incorporate a phosphate fertilizer into the soil before or at time of sowing to encourage development of roots.
4. Sow shortly after the rains have begun so as to take advantage of soil nitrogen so as to take advantage of soil nitrogen that is added to the soil during the dry season. Use recommended seed rate for a variety for example, 5-10 kg/ha of grass and 2-6 kg/ha of legume seed of high quality suffice to obtain desirable stands. The planting depth is usually related to seed size. The optimum depth of most grasses and small-seeded legumes lies between 1.0 cm and 3.0cm.
5. Control weeds by uprooting

Grass legume pasture mixtures

importance of grasses in the grass- legume pasture mixtures

1. It increases total herbage production. Certain grass legume pasture combinations give more herbage than pure stands.

2. It increases the energy value of pastures. Although grasses are generally lower in crude protein content than legumes, they provide the bulk of the energy ration.

3. It suppress weeds. Under proper management, perennial grasses maintain a dense sward that reduces chances of weeds invasion.

Importance of legumes in the grass-legume pasture mixtures

1. Legumes increase the amount of crude protein available to the grazing animals.

2. Legumes extend the grazing period into the dry season by remaining green in the dry period. Even when they turn brown, their nutritive value remains high.

3. They provide nitrogen to the companion grasses. The nitrogen fixed by the legumes is transferred to the grasses when nodules come off their roots.

4. Because of their deep-rooted system, legumes are able to tap leached nutrients from deeper soil layers to the top soil.

5. They shed leaves that cover the soil surface, hence conserving soil moistures and lowering soil temperatures.

Pasture improvement

Signs that shows a natural pasture needs improvement

1. The presence of a layer of undecayed plant residues, which prevent movement of water and air into the soil.
2. The presence of poor unproductive grasses.
3. Wet areas containing marsh plants.
4. Poor condition of the animals.
5. Livestock hunting for palatable grasses.

Methods of pasture improvement

1. Ploughing and replanting of poor natural grassland.
2. Controlled burning to reduce the layer of dead materials and promote new growth.
3. Distribute watering points evenly in the pasture to ensure uniform grazing.
4. Clearing of shrubs and trees to enable the pastures grow better.
5. Perimeter fencing and division of the area into paddocks to allow controlled grazing.
6. Practice closer herding to give uniform of all paddocks but do not over do it to avoid overgrazing.
7. Apply some fertilizers to the pastures such as phosphates to improve soil fertility hence encouraging establishment of new plants.
8. Seeding or over sowing the grassland with desired varieties and spot sowing with nutritious legumes and grasses.
9. Conserve some areas of green pastures in form of standing hay for the dry season to allow setting of seeds, which will disperse and germinate in the following rain season.
10. Provide salt areas and shade trees for the animals.
11. Apply some lime to reduce acidity and encourage breakdown of the mat of the dead materials.
12. Drain swampy area if necessary.
13. Irrigate when necessary.

Management of already established pasture

1. Control weeds from the pasture
2. Practice; correct grazing management e.g. rotational grazing to allow pasture to recover.
3. Maintain correct stocking rate to ensure proper pasture utilization.
4. Broadcast fertilizers especially nitrogen fertilizers to enhance growth and nutritive quality.
5. Overgrow with legumes to maintain balance between species.
6. Irrigate when necessary.
7. Carry out topping to ensure fresh growth.
8. Drain water logged areas.

Meaning of some terms applied in forage establishment and management

1. Seed inoculation. It is the addition of effective rhizobia to leguminous seeds prior to planting to promote nitrogen fixation. Nitrogen fixation in a legume takes place only where its roots is infected by the right strain of rhizobia. Some rhizobia strains are naturally found in the soil.

2. Under sowing. This refer to establishment of a pasture under crop cover usually maize. The benefits of under sowing include facilitation of more intensive land utilization and encouraging an early establishment of pastures.

3. Over sowing. This is the introduction of a pasture legume in an existing grass pasture. Some form of growth suppression of existing grass such as burning, slashing or hard grazing is recommended before over sowing is done. The grass must be kept short until the legume is fully established.

4. Topping. This is the removal of stemmy fibrous materials left over after a period of pasture grazing. The removal of such materials stimulate fresh regrowth. Topping should be done at the onset of the rains and subsequently during wet season. Preferably followed by top dressing. Topping is often done using slashers and pangas.

Grazing management systems/ forage utilization methods

1. Continuous grazing.

This is an extensive system of grazing where livestock remain on the same pasture area for long periods. It is mainly practiced in tropics and is the best for low yielding pastures.

Advantages of continuous grazing.

1. Fencing cost are reduced.
2. Allow animal to have free access to any part of the pasture.

Disadvantages of continuous grazing.

1. Permits selective grazing that lead to wastage of herbage and a patchy pasture.
2. It encourages the build up of ticks and internal parasites of cattle.
3. Results in under/ overstocking as plant growth and seasonal conditions change.

2. Rotational grazing. This involves dividing of the pasture into paddocks and allowing the herd to graze in one paddock at a time until the herbage is uniformly grazed to a given height. The herd is then moved to another paddock and so on.

Another form of rotational grazing is strip grazing, where a small section of pasture is separated from the rest by electric fence and animal permitted to graze. When herbage is grazed to given height, the fence is moved so as to encircle another portion of pasture to be grazed next.

Advantage of rotational grazing

1. Provides a uniformly developed sward due to uniform grazing.
2. Allows maximum utilization of herbage since selective grazing is avoided.
3. Interval between grazing allow for remedial practices i.e. fertilizer application.
4. Forage yield is potentially higher.
5. Grasses are grazed at their maximum feed value.
6. Control parasites and diseases by breaking their life cycles.
7. Cow dung and urine are well distributed through out the field.
8. Controls soil erosion.

Disadvantages of rotational grazing.

1. The capital for fencing and maintaining fences is high.
2. Laborious in terms of movement of water troughs or many installation of water troughs.
3. The chances of bloat are increased since the lush fresh grass cannot be wilted before consumption.

3. Zero grazing/ stall feeding.

This is a method where fresh fodder is cut everyday and fed to the animals confined in stalls. Other feed materials used include crop residues, agro- industrial by-products (e.g., cereal brans and seed cakes) and commercial concentrates.

Advantages of zero grazing

1. Reduces wastage of pasture due to trampling and dung by livestock.
2. Animals are protected from adverse climatic conditions and thefts.
3. Animals conserve energy which is reflected in higher production.
4. Manure can be easily collected and returned to the gardens
5. The grass can be wilted a bit to reduce the risk of bloat.
6. Prevents animals from picking parasites and diseases from communal grazing lands.
7. Higher stocking rate per unit area. It is also possible to keep animal where land is limited.
8. Closer observation of the animals.
9. Easy to carry out practices like castration and deworming
10. Possible to utilize pasture land in difficult areas e.g. on very steep slope.

Disadvantages of zero grazing

1. Method is capital intensive. e.g., initial cost and maintenance of stall is high.
2. The methods is labour intensive i.e, collecting fodder and cleaning the stall daily requires a lot of labour.
3. The animals' choice of feed is restricted.
4. It requires skills and high level management.
5. High incidence of foot rot.

4. Deferred grazing

This refers to setting aside some paddocks for accumulation of standing hay which is to be grazed at a later time.

Advantages of deferred grazing

1. provides fodder in the dry season.
2. Enables the setting of seeds for regrowth of pastures.

Disadvantages of deferred grazing

1. The nutritive value of the pasture becomes low.
2. The palatability of grasses is low.

5. Night paddocking

This is a system of grazing where animals are confined to a paddock where they can graze even at night.

Definitions of some terms used in pastures

1. Fodder. A grass or legume that is cut and carried to the stall for indoor animal feeding
2. Forage. A plant grown primarily for feeding livestock.
3. Herbage. The leaves, stem and other succulent parts of forage plant upon which animals feed
4. Carrying capacity. This refers to the number of animals a given pasture is able to support for agiven period of time.
5. Grazing intensity. This refers to the number of animals per unit area of available herbage.
6. Set stocking. This is a practice where animals are added or taken away from grazing unit of land in order to match animal numbers with available herbage.
7. Stocking rate. This refer to the number of animals in a unit area of pasture land irrespective of available herbage.

Herbage conservation

Herbage conservation is a practice of preserving herbage that is abundant in wet season so that it can be used at a time when green herbage is scarce. Herbage can be conserved either as hay or silage.

1. Hay

This is the grass or legume, which has been cut just before flowering stage and dried.

Procedure of making hay.

1. Grass is cut at the onset of flowering and left in the field for 3-4 days to wilt.
2. The grass is cut and partially dried under shade. Drying is done to prevent the hay from rotting, going mouldy and to ease storage.
3. It is protected from rain to prevent it from rotting and going mouldy.
4. The partially dried grass is then baled for ease of storage.
5. The materials may be alternatively chopped and compressed into pellets.
6. It is then stored in a leak proof shed.

Factors affecting quality of hay

1. Type of grass and legumes used. Some grasses are more leafy and nutritious than others.
2. Stage at which the grass is cut i.e. cutting should be just before flowering. If the cutting is delayed, the nutrient content is lower.
3. Degree of turning. The hay should be properly to ensure uniform drying.
4. Species of grass or legume used. Some grass and legume species are easier to convert into hay than others.
5. Storage. Protect it from rain so as to preserve its nutritive value, aroma and taste.
6. Handling of the hay. The turning, drying and bailing should be done carefully to prevent loss of leaves which contain most of the nutrients and are most digestible.

2. Silage

Silage is herbage cut before flowering and converted into a succulent feed through the process of fermentation.

Procedure of making silage

1. Cut the grasses when they are about to flower and legumes when they are poding.
2. Chop them into small pieces to ease fermentation.
3. Crush them with a roller to ease compaction
4. Place them into an air tight chamber or silo to create anaerobic conditions.
5. The materials are continuously compressed to remove any air.
6. Add additive like molasses and mineral salts to provide energy for the micro organisms that ferment herbage. Consolidate the material to reduce oxidation
7. When the silo is full, it is sealed to exclude any excess air using polythene and soil.
8. Dig a trench around the silo to drain away rain water.

Types of silos used

1. Tower silos. These are long feed hopper with inner glass or asphalt lining to prevent silage from sticking to the sides. Silage comes down by gravitational force.
2. Silage pits or silage trenches. These are usually 15 cm long 6m wide and the walls should be slanting inwards. Well-drained sites are selected. Sealing is done by covering either plastic sheet and soil.
3. Sillage clamps or stack silos. They are constructed by erecting two facing walls of concrete so that silage is packed in the middle. The floor is made of concrete. Sealing is done by covering with plastic sheet and soil.

Advantages of silage over hay

1. it improves the appetite and intake of it by the animals.
2. There is very little wastage, as the animals tend to consume everything due to silage being palatable.
3. Silage can be made from many crops
4. silage cannot be burnt easily by fire as hay.

Factors affecting quality of silage

1. Stage of growth of the species ensiled. Some plant material contain more nutrients than others.
2. Consolidation to exclude air (oxygen). Poor compaction causes rotting hence poor quality of silage.
3. Type and amount of additives used. Amount additives added increase nutritive value and palatability of silage.
4. The pH of the material ensiled. A pH4 is best since it also preserve the silage.
5. The degree to which the temperature rises during ensiling. Very high temperatures lead to poor quality silage because there is breakdown of proteins.

Problem encountered in silage making and use.

1. High capital costs of the machinery and equipment.
2. Additional expenses are involved in buying additives
3. when fed to the animals before milking the smell may contaminate the milk.
4. Requires a lot of labour.
5. It may be difficult to compact the materials properly.
6. It requires a technical know how to make silage.

Important pasture species (grasses)

1. Elephant grass ( pennisetum purpureum)
   . This is a tall perennial grass that grows in areas of moderate to heavy rainfall. The grass is established from whole canes, cane cutting or rooted shoots.
2. Kikuyu grass ( pennisetum cladestinum)
   . A perennial grass that grow at mid altitudes. It is established by use of slips.
3. Rhodes grass ( chloris gayana)
   . It is a stoloniferous spreading grass best suited for grazing. It is established from seeds, splits or stolons. It grows well with sirato, stylo, centro and desmodium. It is very good for hay making.
4. Guinea grass ( Panicum maximum)
   . A perennial that is drought resistant and nutritious . It can be raised from seeds or from splits. It requires well distributed rain and fertile soil.
5. Signal grass ( Bracharia spp)
   . It is a perennial that is adapted to wet areas. It tolerate wide range of soil. It is established from seeds.
6. Jaragua grass / thatching grass ( hyparrhenia rufa)
   . It is tufted perennial grass. It has a low leaf stem ratio at advanced stages of growth. It requires a long period of rest after grazing. It is established from seeds.
7. Star grass ( cynodon dactylon)
   . It is a stoloniferous grass, established from splits and grows best in highly fertile soils and heavy rainfall.
8. Nandi grass ( seteria spp). It is a stuffed grass that grows vigorously in the rain season. It is established mainly from seeds. It is mainly used for grazing but can be used as hay.

Important pasture (legumes)

1. Stylo (stylosanthes gracilis). It hairy with small pointed leaves. It can yield even on infertile soils. It mixes well with jaragua grass. It is established by seeds and also stem cuttings. It is a very good legume for over sowing in natural pastures. It makes good hay.
2. Green leaf desmodium (desmodium intortum). It is a large trailing and climbing perennial which has roots at nodes and has a deep tap root. It spreads readily and fixes nitrogen effectively. It is established by seeds or splits.
3. Sliver leaf desmodium ( desmodium uncinatum). It has a large hairy stem. The leaves have silver patch along the mid rib. It is established by seeds.
4. Centro ( centrosome pubescens). It is a vigorous creeping, twining and climbing perennial legume. It is leafy with slightly hairy stem, which becomes woody after 18 months. It mixes well with tall grasses.
5. Lucerne (medicago sativa). It grows best in highlands. It is established by seeds.
6. Siratro (Nacroptilium atropurpurenum). It is a creeping legume with lobed leaves , highly resistant to grazing pressure and fire. It mixes well with short grass species. It is propagated from seeds.
7. Lab lab ( lablab spp)
8. Glycine (Glycine wightic).