The following areas of agricultural engineering specialization is identified in Nigeria today

1. Farm power and machinery engineering (FPME)

Farm power and machinery engineering is concerned with the development and utilization of power and machinery in agricultural production. This option is divided into farm power and farm machinery: Farm power deals with power generation and availability on the farm while machinery deals with other machine other than farm power for job delivery on the farm. Most fruits and fiber comes from the farm, which means that plants must be grown and animals produced to supply man’s needs. Anyone who has grown plants or worked with any of the sources of power in preparation of seedbed, planting, cultivating, irrigation, thinning etc. has done a hard work. It is generally agreed that there will be some elements of drudgery to such tasks the farmer will strive to lessen the work to reduce drudgery. Progress was then made by the application of power-operated machinery. 

2. Soil and water conservation engineering (SWE)

Soil and water conservation engineering employs principles of engineering in solving soil and water management problems. The conservation of these vital resources implies utilization without waste so as to make possible a high level of production, which can be, continued indefinitely. The agricultural engineers and other scientists have humorous duty in developing new practices that will permit storage in the soil profile of greater percentage of the available precipitation. Design of effective level bench terrace system with special water catchments areas, tillage practices that modifies the soil surface configuration so as to refrain precipitation and reduce the total evaporation potential and surface evaporation control through the use of mulching and films are all challenges for engineers. 

3. Irrigation and drainage engineering

Irrigation is defined as the application of water to land using means other than the natural rain, the purpose of which is to provide sufficient water for plant growth and productivity.  Irrigation is necessary to provide enough water to fill the deficit arising from the depletion of soil moisture from the combine action of two separate phenomena of evaporation and transpiration. 

Land drainage deals with the control of water logging and soil salinization in agricultural lands. In flatlands, a first problem emerges if soil infiltration rates are low and rainfall or irrigation water stands on the ground surface in small depressions or at the edges of the irrigation basin. This problem can be solved by levelling and smoothing the land and providing it with a uniform slope for excess water to flow through furrows or shallow ditches toward the surface drainage outlet. Surface water is discharged into a collector drain through pipes to prevent the erosion of the open ditch bank.

4. Post-harvest systems engineering

This deals with the processes and machines required to convert agricultural raw materials or products into finished consumer goods. It involve, harvesting, transporting, handling, storage, processing and packaging

5. Farm structures and environmental engineering

 Farm structures include farmstead, settlements, animal houses, storage structures farm and allied products, machinery and processing equipment house etc. These structures need specialized designs. Control of environmental factors, external and within in the structures, waste disposal systems, biogas generation etc are also involved. Operations and management of food processing machines such as rice mills, flourmills, vegetable oil processing outfits, beverages and biscuit manufacturing, bread and other confectioneries.

6. Wood products engineering

 This branch of engineering has not been fully developed in Nigeria educational curriculum. It involves the study of engineering properties of woods, composite products from wood and associated wood products processing; design of machines required for forestation projects, exploiting forestry products and management of wood waste products. This includes machines for planting, pruning, logging, transporting, milling, densification and other wood processing machines.

Advancements is areas of agricultural engineering specialization 

Agricultural engineering has advanced in content to the extent that the scope had been widened to embrace various emerging technologies within the field and thus the following specialized categories have been identified: 

a.  Biological (Bioresources) engineering

Biological engineering is one of the most rapidly growing sub-disciplines of agricultural engineering that applies engineering practice to problems and opportunities presented by living things and the natural environment. Areas of interest range from environmental protection and remediation, food and feed production, medicine and plant-based pharmaceuticals and packaging materials. Others may develop techniques and strategies for natural pest control and treatment of hazardous wastes, for composting, and for enzyme processing of biomass, food, feed, and waste 

b.  Agricultural and environmental engineering

These engineers are equipped with expertise in agricultural and environmental works to better understand the complex mechanics of these resources, so that they can be used efficiently and without degradation. These engineers determine crop water requirements and design irrigation systems. They are experts in agricultural hydrology principles, such as controlling drainage, and they implement ways to control soil erosion and study the environmental effects of sediment on stream quality. Natural resources engineers design, build, operate and maintain water control structures for reservoirs, floodway’s and channels. They also work on water treatment systems, wetlands protection, and other water issues. 

The outlook for employment in agricultural engineering and environmental technology continues to be very good. There are more people consuming more food and agricultural products with more preparatory processing than ever before. This leads to a greater need for trained professionals to design environmentally sound production systems. This means more jobs in service, sales, development and application of mechanical systems in agriculture and in protection and management of water, soil and air resources.  

c. Power systems and machinery design engineering 

These agricultural engineers focus on designing advanced equipment, making it more efficient and less demanding of our natural resources. They develop equipment for food processing, highly precise crop spraying, agricultural commodity and waste transport, and turf and landscape maintenance. This is in addition to the tractors, tillage equipment, irrigation equipment, and harvest equipment that have done so much to reduce the drudgery of farming. Their work remains challenging as technology advances, production practices change, and equipment manufacturers expand globally. 

d. Structures and environmental engineering 

These agricultural engineers understand the importance of creating and maintaining a healthy environment for growing agricultural commodities and for the labourers who produce them. They also understand that our natural resources must not be diminished, in quality or availability, by agricultural operations. Toward these ends, these agricultural engineers are equipped with expertise in structures and environment to design animal housing, storage structures, and greenhouses, with ventilation systems, temperature and humidity controls, and structural strength appropriate for their climate and purpose. 

They also devise better practices and systems for storing, recovering, reusing, and transporting waste products. 

e. Food and bioprocess engineering 

Food, fibre, and timber are only the beginning of a long list of products that benefit from efficient use of our natural resources. The list includes biomass fuels, biodegradable packaging materials, pharmaceutical and other products. These engineers understand microbiological processes and use this expertise to develop useful products, to treat municipal, industrial and agricultural wastes, and to improve food safety. They are experts in pasteurization, sterilization, and irradiation, and in the packaging, transportation and storage of perishable products. Food and processing agricultural engineers combine design expertise with manufacturing methods to develop economical and responsible processing solutions for the industry as well as look for ways to reduce waste by devising alternatives for treatment, disposal and utilization.   

f. Information and electrical technologies engineering 

The application of information and electrical technologies in agriculture is very versatile. It is applied to virtually all the other sub-disciplines of agricultural engineering, from machinery design to soil testing to food quality and safety control. Geographic information systems, global positioning systems, machine instrumentation and controls, electro-magnetic, bio-informatics, bio-robotics, machine vision, sensors, spectroscopy are some of the exciting information and electrical technologies being developed and used today in agriculture and agro-based industry. 

g. Forest engineering 

Agricultural engineers apply engineering principles to solve natural resource and environment problems in forest production systems and related manufacturing industries. Engineering skills and expertise are needed to address problems related to equipment design and manufacturing, forest access systems design and construction; machine-soil interaction and erosion control; forest operations analysis and improvement; decision modelling; and wood product design and manufacturing. Forest engineers are involved in a full range of activities in natural resource management and forest production systems. 

h. Energy engineering 

Energy is needed to power the machines, devices, and systems in our homes and workplaces. But many of the energy sources are non-renewable and create undesirable by-products. Agricultural engineers are at the forefront of the effort to identify and develop viable energy sources such as biomass, methane, and vegetable oil and to make these and other systems cleaner and more efficient. These engineers also develop energy conservation strategies to reduce costs and protect the environment, and they design traditional and alternative energy systems to meet the needs of agricultural operations. 

i. Aqua cultural engineering 

As natural fish supplies are threatened, agricultural engineers are needed to help design farm systems for raising fish and shellfish, as well as ornamental and bait fish. They specialize in water quality, biotechnology, machinery, natural resources, feeding and ventilation systems, and sanitation. They seek ways to reduce pollution from aqua cultural discharges, to reduce excess water use, and to improve farm systems. They also work with aquatic animal harvesting, sorting, and processing. 

j. Nursery & greenhouse engineering 

Nursery and greenhouse operations just like large-scale production agriculture have many similar needs of advancement in technology such as irrigation, mechanization, disease and pest control, nutrient application etc. However, other engineering needs also present themselves in nursery and greenhouse operations such as equipment for transplanting; control systems for temperature, humidity, and ventilation; and plant biology issues, such as hydroponics, tissue culture, and seedling propagation methods. 

k. Safety and health in agricultural engineering 

Farming is one of the few industries in which the families work and live on the premises and are at risk for injuries, illness, and death. Agricultural engineers analyze health and injury data, the use and possible misuse of machines, and equipment in compliance with standards and regulation. They constantly look for ways in which the safety of equipment, materials and agricultural practices can be improved and for ways in which safety and health issues can be communicated to the public. 

Emerging technologies in agricultural engineering

The discipline is currently undergoing major and important changes as it responds to global economy. These emerging technologies (ET) include: Information technology (IT); Biotechnology Environmental and renewable energy sources. The use of computer and communication (ICT) equipment’s for Data acquisition, machine control, information management and simulation and prediction of agricultural systems are becoming popular. Biotechnology involves the engineering of biological systems. Waste recycling, alternative to fossil fuel- vegetable and fruit oil-fuels etc. Renewable energy resources such as harvesting and utilization of solar, water wind energy for agricultural production, processing and handling. 

Advances in agricultural engineering technology practice

Advances in Agricultural Engineering technologies have been listed by the American National Academy of Engineering as one of the most significant engineering achievements of the millennium. These advances in technologies have constituted one of the most important inputs into agricultural production which are the basis for human survival. In a world of steadily changing demands, the face of agricultural engineering has changed dramatically over the last hundred years and new challenges will have to be faced in future (Lawrence, 2000). 

Few among many areas in which Agricultural Engineering technology have made significant advancement include.

a.        Education and training:  Education and training in agricultural engineering has provided platforms for further development through academic curricula updates for better correspondent to market demands, better food security and expected rapid developments in the agro-industrial sector. For example, Japan and the United States of America and many more EU institutions have modified and are expanding in the areas of the names of their faculties, to such names as “Natural and Land resources”, Bioresources/biosystems engineering, or Biological systems engineering etc. 

b.       Farm implements and machinery: Various developments and advances have been made in such areas as land levelling with the laser-beam technology (laser-guided leveller). This technology has recorded 73% variation in the land levels before and after bed preparation. Without the laser-guided beam technology, percentage variation in the levels documented was only 8% before and after the test. Other recent developments include two-row vegetable trans planter, Flail-type Forage Harvester-cum-Chopper which could harvest forage of 80-mm size. Flail-type Chopper-cum-Spreader. Cultivator frame Banana-Clump Remover has been developed for removing banana suckers, Light-weight power-tiller for hill side agriculture etc 

c.          Self-propelled and animal-drawn machinery: Eight-row Pre-Germinated Rice-seeder, Walking-type Sprayer- A 8-row pre-germinated rice-seeder, IISR Bullock-drawn Single-row Potato Planter, Bullock-drawn Groundnut-planter, Bullock-drawn Cultivator/Blade-harrow among order innovations has been recorded.

d.         Stationary machinery High-capacity Pigeon Pea Thresher, Pedal-operated Potato slicer, cassava lifter, grain cleaners etc. Design-refinement in Mills etc was other areas of rapid developments which are indigenous to Nigerian engineers.

e.          Ergonomics studies have also increased in the evaluation of the commercially available human-machine interface systems such as pedal operated systems, Manually-operated Hanging-type equipment’s etc.

f.          Post-harvest engineering and technology has led to the development of candies and bars from mango, guava, banana and pineapple with different combinations of soymilk, soy flour, cashew nut, pilot-scale puffing machine to process 20-kg raw potatoes.  a stepwise-expanding pitch-fruit grader, solar air-heater to dry high moisture rice, Colour Meter to measure maturity of mango on the tree, determining maturity of intact mango on tree etc

g.         Electronics and mechatronics systems: Replacing mechanical functionality with electronic functionality might also reduce manufacturing costs. Just as electromechanical servomotors are computer-tuned to get responses based upon their industrial application; agricultural equipment components can be similarly adjusted. For example, the same electro-hydraulic valves might give different optimal performances in different applications.

h.          Other advances: This include plastic mulch for economizing irrigation-water in baby corn resulting in 36.0% increase in yield over ridge-planting, Bio-rational approach for integrated pest management (IPM), Processing of jute-sisal blends in jute machinery machine for compaction of cotton-stalks. Bio-diesel from oil of nonedible plants etc.