A nursery bed can be defined as a piece of land of any convenient length prepared for raising seedlings for later transplanting. A seed bed refers to a piece of land of any size that has been prepared for sowing seeds or receiving planting materials. A seedling bed is a special type of nursery bed used for raising seedlings that have been removed from a nursery bed due to overcrowding before they are ready for transplanting.
LEARNING OBJECTIVES
By the end of this lesson, you should be able to:
- Explain the importance of raising seedlings in a nursery bed.
- Describe the factors considered when selecting nursery bed sites.
- Explain the nursery establishment.
- Explain the different nursery management practices.
Importance of raising seedlings in a nursery bed
They include the following:
- Raising seedlings in a nursery bed economizes on the use of seeds, chemicals, and water.
- It gives the farmer a head start in planting, hence early maturity for crops.
- It reduces the amount of labor spent caring for the seedlings.
- Many seedlings are raised in a small unit area.
- It reduces the time taken by the crop in the field.
- It enables a farmer to select healthy and vigorously growing seedlings that establish faster.
- It is easier to manage the seedlings in terms of weeding, watering, and controlling diseases and pests.
Factors to consider when selecting a site for a nursery bed
The following factors are considered before establishing a nursery bed:
- Type of soil: The site should have soil that is well-drained, deep and fertile, preferably sandy loam.
- Nearness to a water source: A nursery bed should be established near a water source for easy watering.
- Security: It should be well secured from intruders.
- Topography: It should be established on a gently-sloping land to enhance drainage.
- Previous cropping: Areas, where the same crop species had been planted, should be avoided.
NURSERY ESTABLISHMENT
Preparation of a nursery bed
- Select a suitable site and mark it out.
- Clear vegetation.
- Dig or plough the site deeply to remove all perennial weeds.
- Harrow the bed to a fine tilth and then level it.
- Measure and divide the nursery bed into sections, about 1 meter wide and any convenient length, with 60 cm paths between individual beds.
- Broadcast a phosphatic fertilizer or well-rotten manure.
- Mix the fertilizer or manure well with the soil using a rake.
Planting in a nursery bed
- Make shallow drills, about 1 cm deep and 10- 20 cm apart.
- Drop the seeds uniformly in the drills.
- Cover the seeds lightly with soil.
- Spread a thin layer of mulch on top of the bed.
- Water the nursery bed and erect a shade to minimize water loss through evaporation.
Some nursery beds are established vegetatively. The rooting of cuttings in such cases is affected by the following factors:
- Temperature: Warm soil temperature encourages faster rooting as opposed to low soil temperature.
- Light intensity: In most cases, lack of light encourages rooting in hardwood plants, whereas high light intensity enhances rooting in softwood plants.
- Relative humidity: High relative humidity lowers the transpiration rate, which favors fast rooting of cuttings.
- Oxygen supply: A well-aerated rooting medium encourages faster rooting.
- Chemical treatment: Rooting hormones, when applied at the base of cuttings quicken the rooting process.
- Moisture supply: The root forming process requires an ample supply of moisture.
- Leaf area: Some cuttings require some leaves for photosynthesis to quicken rooting.
Nursery management practices
The routine nursery management practices include:
- Hardening off: This is the gradual exposure of seedlings to conditions close to those found in the field after transplanting. It is done by reducing the amount of shade or mulch, and the frequency of watering the seedlings. This enables the seedlings to withstand harsh conditions in the field.
- Shading: This involves the erection of a shade over the nursery bed. It is done to prevent scorching of seedlings by direct sunshine. It also prevents damage of seedlings by raindrops and hardening of the ground around the seedlings as a result of impact by raindrops.
- Thinning: This is the removal of excess seedlings from the nursery bed. The removed seedlings are taken to another space within the same nursery bed or to a seedling bed. It reduces overcrowding in the nursery, hence enabling the seedlings to grow vigorously and healthily.
- Pricking out: This refers to separating out seedlings growing together and transferring them into their own pots. This should be done when the seedlings are big enough to handle it without drying out.
- Mulching: This is the spreading of mulch materials like leaves around the base of seedlings. It is done to insulate the soil against moisture loss.
- Pest and disease control: This involves using appropriate methods like spraying, to control diseases and pests.
- Watering: This is the application of water to the nursery bed. It is done to maintain the right moisture levels in the nursery. Watering is done when the conditions are dry.
- Weed control: It involves controlling weeds to reduce their competition for growth factors with the seedlings. It is done by uprooting the weeds to minimize root disturbance.
