TIME OF PLANTING
The timing of planting or sowing is inﬂuenced by the type of crop to be planted and the environmental conditions of the area.
Factors to consider in timing planting.
- The rainfall pattern/moisture condition of the soil.
- Type of crop to be planted.
- Soil type.
- Market demand.
- Prevalence of pests and diseases.
- Weed control.
- Timely planting is necessary and should be done at the onset of rains. in some areas where rainfall is scare dry planting is recommended.
Advantages of timely planting.
- Crops make maximum use of rainfall and suitable soil temperature, leading to vigorous growth.
- Crops usually escape serious pests and diseases attack.
- Crops benefit from nitrogen flush which is available at the beginning of the rain.
- For horticultural crops, proper timing ensures that the produce is marketed when prices are high.
- Crops establish earlier than the weeds, hence smothering them.
Methods of planting.
There are two main methods of planting:-
- Row planting.
This method involves scattering the seeds all over the field in a random manner. It is commonly adapted for light tiny seeds such as those of pasture grasses.
It is easier, quicker and cheaper than row planting. However, it uses more seeds than row planting and the seeds are spread unevenly leading to crowding of plants in some places.
This results in poor performance due to competition. Broadcasting gives a good ground cover, but weeding cannot be mechanized. For good results, the seedbed should be weed-free, firm and have a fine tilth.
The seeds or other planting materials are placed in holes, drills or furrows in rows. The distance between one row to the other and from one hole to the otheris known.
In Kenya, both large and small — scale farmers practice row planting. It is practiced when planting many types of crops, especially perennial, annual and root crops.
Advantages of row planting.
- Machines can be used easily between the rows.
- It is easy to establish the correct plant population.
- Lower seed rate is used than if broadcasting is adopted.
- It is easy to carry out cultural practices such as weeding, spraying and harvesting.
Disadvantages of row planting.
- It does not provide an ample foliage cover. Thus the soil is liable to being eroded by wind and water.
- It is more expensive than broadcasting because of consuming a lot of labour and time.
- It requires some skill in measuring the distances between and within the rows.
Seeds can also be planted by dibbling where the planting holes are dug by use of pangas or jembe, or by a dibbling stick (dibbler). Most of the dibbling is done randomly although rows can also be used when using a planting line.
Random dibbling is not popular in commercial farming due to low levels of production. It is only common among conservative farmers in planting of legumes such as beans, pigeon peas and cow peas.
This is the introduction of a pasture legume such as desmodium in an existing grass pasture. Some form of growth suppression of existing grass such as burning, slashing or hard grazing plus slight soil disturbance is recommended before over sowing. A heavy dose of super phosphate, preferably single supers at a rate of 200- 400 kg/ha is applied.
The grass must be kept short until the legume is fully established. Regardless of the method of establishment, the pastures and fodder stands should be ready for light grazing 4-5 months after planting if rainfall and soil fertility are not limiting.
This refers to the establishment of pasture under a cover crop, usually maize. Maize is planted as recommended and weeded 2-3 weeks after the onset of rains. Pasture seeds are then broadcasted with half the recommended basal fertilizer.
No further weeding should be done and maize should be harvested early to expose the young pasture seedlings to sunlight. The benefits of under sowing include facilitating more intensive land utilization and encouraging an early establishment of pastures.
Fodder crops and vegetetively propagated pasture species may also be under sown as long as rainfall is adequate for their establishment. Timing is not very crucial in this case and planting can be done as late as 6-8 weeks after the onset of rains.
This refers to the ideal number of plants that can be comfortably accommodated in any given area, without overcrowding or too few to waste space.
Agricultural research has arrived at the optimum number of various crop plants to be recommended to farmers. Plant population is determined by dividing the planting area by spacing of the crop. This may be simpliﬁed thus:
Plant population = Area of land divided by Pacing of crop
Given that maize is planted at a spacing of 75 x 25 cm, calculate the plant population in a plot of land measuring 4 x 3 m.
Area of land = Plant population divided by Pacing of crop
Area of land = 400 cm x 300 cm
Spacing of maize = 75 cm x 25 cm
Therefore, plant population = 400 cm x 300 cm
75 cm x 25 cm
= 64 plants.