Agricultural engineering

Agricultural engineering means the application of engineering knowledge to agriculture. The agricultural engineer must understand that there are basic differences between agriculture and other industries. The biological factor is an important one in engineering applications, and the engineer must know well the basic principles and practices of agriculture.

Changes in cultural practices often need to make a machine adaptable or to increase its effectiveness. Processing equipment may also need changes to harvest crops mechanically, for the quality of yield of a crop may sometimes be reduced by the use of an improper machine.

Most field operations are seasonable in nature often with only a short period of time in which to do the job. Therefore field machinery in many cases has a low annual duty (i.e. very few hours of operation per year).

The field of farm machinery design gives greater opportunity to an engineer than any other field of engineering. Farm machines must work where the temperature may be above 100°F or where it is below freezing. They must be able to work in rain and in snow as well. Instead of resting on the floor of a factory, they must operate over any kind of land. They must also be designed to handle wide variations in crop and soil conditions.

Not only agricultural engineering in the field of mechanisation are in demand on the farm today. Electricians, i.e. agricultural engineers capable of designing, operating, controlling and adapting any form of electric energy to farm needs are wanted by modern agriculture.

As is known, electric power has become the main source of energy in agricultural production and its sphere of application is ever increasing. For example, it is a most reasonable source of mechanical power for some kinds of equipment such as electric motors which are very suited for farm jobs because of their automatic control, long life, compact construction, ability to run in cold or hot weather, etc.

All kinds of equipment for handling milk, such as milking machines, milk coolers, water heaters and others are also operated by electricity.

The great effects of various types of radiation on seeds, plants, insects and animals have been studied and are well known today. Those are but a few examples of electric power application on the farm which a modern ag-engineer must work with.

Agricultural engineering in the usa and britain

The Past Development of Agricultural Engineering. No doubt the history of agricultural engineering development could be written in many different ways. But agricultural engineering activity has reflected the trends of agricultural production in the past, and the present and future trends in farming will determine the activities of agricultural engineers in the future.

Thus, as we look back we can see that agricultural engineering in Britain in the past was mainly on mechanical engineering. The scale of manufacturing operations has increased from that of the village blacksmith to that of the large mass-production plant, often controlled by an organisation that is international in character.

Developments in Farming. While standardization of manufacturing industry has been taking place, parallel changes in farming organization and production have also taken place. Thus, farm sizes have increased, the investment in machinery/man employed has also increased, and so the sophistication of much of the equipment. The total engineering investment into farming is thus increasing.

Farms become larger and more specialized. Their products, as well as engineering products, become more standardized. A new feature is that the farmer can no longer grow any crop he likes and expect to sell what is produced. He, too, is subject to market demands as to type, quality, time of production and the requirements of processing and packaging. Such control may include specifying the type and timing of field operations, or the operation of harvesting and first-stage processing machinery; or of drying processes for cereals, or pest control for fruit and vegetable crops, and so on.

Some of these sources of control must use agricultural engineering expertise, and opportunities for agricultural engineers to be connected with process control are likely to increase.

Other Engineering Investments into Agriculture. Agricultural engineers with a mechanical education will continue to play an important part in applying their knowledge to agriculture. There will also be growing opportunities for other kinds of engineering. On many territories soil and water engineering is more important in its application to agriculture than any other branch of engineering, in connection with erosion control, irrigation and drainage. The intensification of livestock husbandry and the control of environment that may go with it includes heating and ventilating engineering, mechanical handling of feed materials, and some aspects of automation. In intensive glasshouse crop production there are needs, which require a great range of engineering knowledge, and so also does mechanization – mechanization of operations in and around the farm buildings.

One characteristic of many of these applications of engineering is that if they are to be effective there must be understanding of scientific subjects which agricultural engineers in the past have not had to understand. Thus, agricultural engineers working on the control of environment for animals or plants may well have to know something of animal or plant physiology as well as of animal behaviour. Those busy with automatic control systems will be unable to use their own knowledge unless they are able to understand the animal or plant physiologists. They, in turn, must have some understanding of the limitations of practical engineering installations, and of the fact that engineers cannot design systems of any kind unless they are provided with the basic information. So agricultural engineers will find it increasingly necessary to work together with agricultural scientists.

Another field of activity which is likely to become important in the near future is 'synthetic' protein production. Much re-synthesized protein has been produced in the USA from soy-beans and is marketed in various ways, including synthetic bacon pieces and other meat products. In Britain similar activities are in progress on an experimental scale, using plants which are best suited to the British climate. The research by plant physiologists, agronomists and others is now such that it may not be long before the growth of field crops specially for protein extraction becomes standard farming practice. So, the primary extraction of protein from green material must take place on farms. There are likely to be tasks connected with the design and installation of farm-scale equipment for protein extraction, and the harvesting, handling and protein storage, which will fall to agricultural engineers.

There are also possibilities of producing food materials of non-traditional kinds, either for human or animal consumption. These include bacterial protein from waste materials, including some from livestock excreta or plant wastes.

Waste Treatment and Utilization. It would be a mistake to think that the productive utilisation of farm waste materials is an easy problem which can be put into practice at once. One of the problems which has been given great attention to at the present time is the possibility of using anaerobic digestion processes to produce methane from animal and plant wastes. Such a possibility exists, and very much heat energy could be got in this way.

For example, if all the manure from a dairy herd of 180 cows could be collected and digested efficiently, the gas output would be equivalent in heat to about 273 litres of petrol a day. But the fact is that the biogas that is produced, having some 65% of methane, gives energy in a form that is only likely to be utilized efficiently if it is burned in an installation at hand. Converting it to electricity would lose 80% or more of the heat, and it is not normally practicable to compress it for use as a fuel for moving vehicles. These points show that there are many problems before this energy can be utilized, and that much research and development will be required. Another very important problem is that biogas is highly explosive when mixed with air, so that there is a strong element of danger in the process unless it is well controlled.