The terms 'planter' is commonly used to describe various of single row seeder attachment to a tractor which are used on a commercial scale for sowing seeds such as maize, rice, groundnuts and Legumes. The term 'drill' refers to seeders which are used for establishing crops in rows about 10-20 cm apart, several rows being sown at one time. In view of the high cost of seed, it is important to obtain an optimum spacing between seeds to avoid unnecessary competition between plants for nutrients, water and light and also to ensure that the required number of plants per hectare are established to produce maximum yields.
The basic components of a drill are: a hopper or box which contains the seeds and which is carried on a frame supported by wheels. From one of these wheels, a drive or metering mechanism regulates the rate at which the seeds pass down a series of plastic, rubber or metal tubes into the coulter assembly.
The function of the coulter is to cut a groove in the soil into which the seeds will fall. The depth of sowing depends on the position of the coulters, this is regulated by the adjustment made to a bar at the front of the drill frame to which the coulters are attached. Many types of drill also have press wheels behind the coulters which firm the soil over the seed.
Combine drills are similar in construction, except that there is an additional hopper or box containing Fertiliser which is fitted to the drill frame. Metering units, usually of the 'plate feed' type, which are located at the bottom of the hopper feed the fertiliser down either the same outlet as the seeds or into separate tubes which lead to the fertiliser assembly.
Drills vary from 2.25-4.0 m in width and to 30 metering units attached to the underside of the hopper. Row spacings may be from 12.5-17.5 cm, depending on the crop.
These are often referred to as planters and the more advanced types may be similar in design to those used with tractors in that they have a box or hopper to hold the seeds, a drive or metering mechanism, delivery tubes down which the seeds pass to the coulters which cut the slots in the soil into which the seeds fall. They may also have press wheels which firm the soil over the sown seeds.
More basic types of planter may be made with a barrel-shaped container for the seeds which has holes drilled at suitable intervals through which the seeds fall to the ground when the hole comes into contact with the soil. Seeders used for row crops can often be adapted to handle fertiliser and some types of seeder are dual-purpose, with fertiliser attachments added to the seeding mechanism.
Weeders,
These are useful for crops which are grown in rows and consist of to five curved metal tines which are up bolted on to a simple supporting frame. The weight of the implement is partly carried on a small wheel at the front and a hand lever is used to adjust the depth of penetration of the tines.
Tool Frames And Toolbars For Ox-drawn Implements,
This are becoming widely used in many areas. They provide more flexibility of choice for the farmer since more than one weeding and seeding attachment
can be bolted on to the frame, enabling a more rapid rate of work to be achieved. In many respects, the ox-drawn toolbar is similar to the tractor drawn toolbar.
Ox-drawn carts,
The ox-drawn cart has been widely used in many parts of Africa for some years. Various designs have been adopted, depending on the availabilifertiliser vl materials, and the type of load to be carried.