The area of land required depends largely on species to be raised, the number of plants to be produced, the time they will spend in the nursery, the density at which they will stand in the beds and area and spacing of the plantation.
Before starting calculation of area needed, it is useful to consider the following components of the nursery.
- Seed beds and trays,
- Standard beds (main plant growing area),
- Paths, roads, irrigation canals,
- Working area, seed storage, including thatched shelter,
- Compost making area,
- Fallow,
- Area for any future expansion.
The area of nursery varies according to the circumstances and should therefore, be calculated very carefully in each case. However, in a general way, it may be said that the area of the nursery may vary from 0.25 to 2.5 % of the plantation area. To estimate the total nursery area, the area of seedbeds is multiplied by 2.5, to include roads and service areas, and 100 Sq. m are added for paths, based on the production of 2000 seedlings per square meter of seed bed. Therefore, in general:
Total nursery area = (2.5 x Area of seed bed) + 100 Sq. m.
A reliable and adequate water supply is essential for all forest nurseries. Preferably, it should come from a perennial stream located above the site and close to it. Water can then be diverted from the stream to the nursery in high density polythene pipe (which should be buried 15cm. deep), or in an open channel. Similarly, an existing irrigation canal may be used. In both cases enquiries should be made to ensure that water is available throughout the year (whenever possible, check the flow in driest months; March, April and May) and to see who else use the supply. This can only be discovered by having full discussions with local people. Again, clear agreement on water use must be obtained and careful estimates of supply and demand made before nursery establishment.
A guaranteed supply of 1000 liters (per 33) of water per day will be more than adequate for a nursery of 20,000 plants that are being watered with a watering can. Nurseries using surface irrigation will require considerably more than this.
