By Hanks Saisai
The successful growth of a crop is commonly influenced by the initial action of propagation, conventionally done through the sowing of seeds into a growing medium or directly into a seed bed.
However, a factor frequently overlooked by farmers when sowing seeds is the sowing depth. Hence, most seed-producing companies develop trials to determine the correct sowing depth of a seed.
Moreover, seeds procured from reputable companies, are usually accompanied by recommended sowing depth.
It is essential to understand that the depth at which a seed is sown has a direct impact on the seed germination time.
When the soil is warm enough, the seed develops a rudimentary root, and at the right depth, the seed ‘s root system grows optimally and has access to essential nutrients such as Phosphorus, Nitrogen and Potassium. In contrast, if the seed is sown too deep and the soil lacks phosphorus, the seed may have limited Phosphorus which is essential for root development.
If the seed is sown too deep, it also affects the emergence period of each crop. Usually, most vegetable seeds have a recommended sowing depth that ranges between 0.5 cm to 2 cm in a growing medium or directly into the garden.
This later translates to a germination and emergence period of about 10 – 14 days for new plants to emerge out of the soil or the planting medium. Once the crop emerges, it has a defined growing period, for instance, cabbage has a growing period of about 90 days before it is ready for harvesting.
However, if the sowing depth guide is not adhered to, it may affect the germination and emergence period. This will directly impact the crop ‘s growth period before a farmer can harvest.
In automated seed sowing operations using a tractor with a planter, the sowing depth is calibrated to ensure proper planting.
The fertilizer is dropped at a depth of approximately 5 – 7 cm, while the planter releases seeds at a depth of about 2 – 3 cm.
This will ensure that the seeds sown have access to major elements such as Phosphorus (P) which is essential for root development, Nitrogen which is responsible for shoot establishment and vegetative growth and Potassium (K) which is responsible for flower and fruit development.
Furthermore, the sowing depth also influences a farmer’s choice of an appropriate irrigation system that ensures that the seeds are not displaced from their original place of planting.
Seed sowing is an aspect that farmers often overlook, however, it is among the most critical aspects of a successful crop production enterprise.
It is therefore essential to grow your seeds correctly to avoid delays in the growth period and harvesting dates of your crops as this ultimately affects your yields and potential revenue.
*Hanks Saisai is Technical Advisor: Crops and Poultry
