Mécanisation agricole durable

On farm postharvest and value addition

Mechanization continues to play an increasingly important role in post-production operations such as shelling, milling, packaging, transportation, storage and marketing. The application of sustainable mechanization in post-production operations through more efficient use of labour, the timeliness of operations, and more efficient field and off field operations contribute to high-productivity systems. In recent years, we have seen tremendous transformation in the design of post-production agricultural machines with the current versions utilizing science and technology advancement. Consequently, high capacity, precise, reliable, energy efficient and relatively easy to operate machines and equipment have been developed. Such machines give value chain players using them a competitive edge over their competitors in terms of the area under cultivation, efficiency of operations and quality of the final products. Examples of the application of mechanization in postproduction operations are given below:

Threshing dehulling and milling operations
Mechanized machines are commonly used for postharvest operations such as threshing, dehulling and milling operations. Operations such as threshing of grains like rice and maize are gradually being undertaken using machines. The introduction of such machines is increasing the productivity and therefore should be encouraged.

In sub-Saharan Africa (SSA) the use of dehulling machines such as Engleberg and rubber roller dehullers are common in maize and rice processing operations respectively, in both urban and rural areas. The efficiency of these machines is far better compared to the arduous traditional manual dehulling methods using pestle and mortar.

The use medium and large scale grain milling machines is becoming popular in the production of packaged cereal flours in Africa. Machines of different capacities are being introduced to cater for the needs of grain millers in urban and peri-urban areas. Hammer mills are widely used in rural areas of Africa for milling maize, sorghum, wheat etc. into flour. They suit well the small scale conditions in rural areas and hence their popularity in SSA.

The operators of such machines source their raw materials from the rural area hence creating market outlet for farmers. Other operations like cleaning, de-stoning, sorting, grading and packaging can be also carried out using mechanized equipment.

Drying of crops is another operation where mechanized machines are useful. Crop drying is an important post-production food preparation operation that can significantly reduce postharvest losses. Different types of dryers are available for crop drying under small, medium and large scale operations. These dryers help to reduce the moisture contents of the harvested crops to the optimal levels before storage. For example, drying of horticultural produce such as fruit and vegetables using solar dryers helps to significantly extend their shelf life.

Processing of roots and tubers
Postharvest processing machines are widely used in processing of root and tuber crops such as cassava and sweet potatoes. Postharvest operations include chipping, grating and pressing. Root and tuber processing machines are available in different sizes suitable for small, medium and large scale operations. Such machines can be operated manually or use both small and large diesel or petrol engines and electric motors to run them depending on the scale of operation and availability of those power sources.

The lack of transportation is one of the many barriers that impedes smallholder farmers’ access to markets and hence to the much needed revenues. Transportation of produces from the farms to the households and from the households to the markets depends very much on the available means of transport such as oxen carts, trailers attached to four wheelers or single axle tractors, trucks etc. Capacity building in terms of training on how to fabricate transportation equipment such as carts and the proper use of oxcarts and other transportation equipment is important.

Hire services
Provision of hire services of postharvest handling machines during post production operations is gaining pace whereby entrepreneurs provide post-harvest handling services to farmers for operations such as threshing of rice and maize. Under such arrangements, entrepreneurs mount their mechanized machines such as maize shellers on four wheeled or single axle tractors or small trucks which are driven around the farms to provide services to the farmers. This is important for farmers as they do not incur extra transportation cost to take their produce to the machine and bring the product back, leading to increased incomes.

Repair and maintenance
It is important to ensure that machines used in postproduction operations are well maintained throughout their operation life. Another important requirement is that machines and equipment must be operating at the optimal level of safety and efficiency and have to be available when needed. Moreover, well maintained machines will perform satisfactorily if all operation parameters and maintenance are kept within the manufacturers specifications. This will help to prolong the use life of the machine, ensure its availability and readiness, ensure safety of operators and their clients who use or come into contact with the equipment, and in the long run obtain maximum return on investment.