Forage Crops

Environmental Issues Human population growth in a developing country induces: Increase in demand for meat and dairy products. Increase in cattle, sheep and goat herds and in parallel a reduction in natural pasture areas, communal land and fallow in order to increase the area under cash crops. Intensification is the only answer to this double challenge, and entails establishing forage crops for targeted livestock. These forage crops can have comparative advantage to cash crops in term of environmental impact. | Environmental Issues Objectives Techniques Costs Targeted Livestock System Impact Context of Application Monitoring: EIA, Indicators References

Objectives

Cultivation of forage to substantially improve forage production or quality. By using appropriate forage species, crop and exploitation practices, the farmer can improve the diet of his livestock.

Globally, cultivation of forage crop answers the following points:

- increase in forage production.
- improvement of forage quality.
- creation of reserves for the season when forage is short (dry season in tropical countries, winter in temperate countries).
- feed for intensive livestock farming.
- rehabilitation of soils (see Mineral fertilisation of pastures).
- improvement of fallow (see Introduction of forage plants in pastures).

But in pastoral systems, particularly in Africa where the possibilities of intensifying forage production are small (fertilisation - irrigation - mechanisation, etc.), the option will not be to use a few species with high production potential, but rather a wide range of species with diverse environmental adaptability.

Techniques

Establishment, maintenance and utilisation require techniques and tools comparable to those of other agricultural crops. The extent of intensification depends on technical-economic conditions and production options.

Different types of forage crops can be distinguished:

- Permanent meadows, composed mainly of grasses and/or perennial legumes. These are either grazed or harvested mechanically.
- Temporary meadows, established for a short period.
- Annual crops, either high-production grains (maize, sorghum, wheat, etc.) preferably harvested, sometimes grazed, or legumes as dolichos (Lablab purpureus), cow pea (Vigna unguiculata), etc. or else various plants grown for their leaves (forage cabbage, chicory) or roots (forage beetroot).
- Crops which are both subsistence and forage: sorghum, cow pea.
- Crops of bushes, shrubs or forage trees.

Availability of agricultural tools is necessary for forage crops: tools for clearing, ploughing, soil preparation, spreading (fertilisers, seeds) cutting, conditioning, and conservation.

Species of plants available for forage are numerous and for almost all eco-climatic regions. It is important to have available a wide range of species making it possible to make more use of good suitability to the context of local utilisation and to reduce costs at all levels (inputs, work, etc.)

Costs
The principle elements of forage crops are the following : establishment of the forage crop, fertiliser, phyto-health protection and labour. Forage maintenance and possibly harvesting or storage expenses should also be taken into account.

Targeted Livestock System
Grazing systems and mixed systems, including dairy production.

Grazing System

LGA | LGS1 | LGS2 | LGS3 | LGH1 | LGH2 | LGH3 | LGT1 | LGT2 | LGT3
N | N | Y | Y | N | Y | Y | N | Y | Y

Mixed System

MCG | MCR | MCC | MFF | MEF
Y | Y | Y | Y | Y

Industrial System

IFP | IPL | IPG | IRM | IDU | ISL | ITN | IMP
N | N | N | N | N | N | N | N

Impact

- Positive environmental impact

- Measures against wind and water erosion by establishing permanent soil cover.
- Improvement of soil fertility by the addition of organic matter (grasses) and phosphate (legumes).
- Participation in crop rotation in some agricultural systems.
- Carbon sequestration in permanent pastures

- Negative environmental impact

- Decrease in soil fertility (without the input of fertiliser or dung), where forage is exported by cutting.
- Compacting of soils by grazing.
- Risk of introducing diseases or destructive species which can affect the indigenous vegetation.
- Risk of introduction of species which become a plant pest locally.
- Introduction of weeds with poor quality seeds.

- Impact on livestock productivity (milk, reproduction, meat, health, etc.)

- Increase in carrying capacity.
- Increase in production per animal and per unit area (milk, meat).
- Improved animal husbandry (less health risk, improved reproduction management).

Context of Application

- Favourable factors:

- Availability of arable land.
- Legislation allowing a long term land use.
- Seasonal forage requirement.
- Possibility of obtaining seed.
- Availability of agricultural equipment.

- Unfavourable factors:

- Aridity and other major climatic constraints.
- Requirement of labour for other agricultural work.
- Cost of establishing the forage crop.
- Insufficiently secure land tenure systems.
- Insufficient utilisation of animal productions.

Monitoring: EIA, Indicators

- Proportion of area under forage crop in relation to area still under grass / natural pasture.
- Quantity of forage produced or feed unit.
- Botanical composition of meadows.
- Nutritional value of forage plants.
- Livestock performance.

References

Bulgen A., Dieng A., 1997. Andropogon gayanus var. bisquamulatus – une culture fourragère pour les régions tropicales. Presses Agronomiques de Gembloux, pp. 171.

Skerman P.J. 1982. Les légumineuse fourragères tropicales. Collection FAO Production végétale et protection des plantes, FAO, Rome, pp. 666.

NAS. 1979. Tropical Legumes : Resources for the Future. National Academy of Sciences, Washington, pp. 331.

T’Mannetje L., 1992. Plant resources of South East Asia. N4 Forages. Wageningen, Pudoc Scientific Publisher, pp.300.

Roberge G., Toutain B., 1999. Plantes fourragères tropicales cultivées. Montpellier, Cirad.

> > [Livestock & Environment Toolbox Home]