Irrigation farming system adopted by a farmer is affected by different determining factors. These factors are major six in number and they include natural conditions, type of crops planted, and type of technology, previous experience with irrigation, required labour inputs, costs and benefits consideration.

Amongst these factors, climatic factors seem to be the one that greatly affects the farmers’ choice more than the other factors. The source of water of the irrigation system was also considered and the study found that water source plays significant role in the choice of irrigation system to be adopted by the farmer.

The basic reason as unraveled by the study was due to the sediments and possibly salt deposits in the water, based on its source. The timing and quantity of water to be applied to the farm was as well considered. This is termed irrigation scheduling.

Factors Determining Types of Irrigation Farming

In choosing an irrigation system, the Engineer or farmer must bear in mind that there is a huge diversity in the types of irrigation technologies/systems used, and the use or application of the different types of these irrigation systems are subject to been determined by different factors.

A report on The Practice of Irrigation-Food and Agriculture stressed that the suitability of the various irrigation methods, i.e. surface, sprinkler or drip irrigation, flood, subsurface, furrow, etc. depends mainly on the following factors such as;

Natural conditions
Type of crops planted
Type of technology
Previous experience with irrigation
Required labour inputs
Costs and benefits consideration

The above major mentioned factors are discussed below:

1. Natural Conditions

The natural conditions are those factors that man have no cause to and has very little or nothing to do about it. Such factors are soil type, slope, climate, water quality and availability, and they have the following impact on the choice of an irrigation method:

a. Soil type: Taking the different types of soil into consideration and their characteristics, Sandy soils have a low water storage capacity and a high infiltration rate. They therefore need frequent but small irrigation applications, in particular when the sandy soil is also shallow.

Such soil would drain water fast and so suggest that under these circumstances, sprinkler or drip irrigation are more suitable than surface irrigation.

On loam or clay soils all three irrigation methods like surface, sprinkler and drip irrigation systems can be used, but surface irrigation is more commonly found. Clay soils with low infiltration rates are ideally suited to surface irrigation.

When a variety of different soil types is found within one irrigation scheme, sprinkler or drip irrigation are recommended as they will ensure a more even water distribution.

b. Slope: Farming on a land that is on a sloppy terrain, the best type of irrigation system is the sprinkler or drip irrigation are preferred to other types of irrigation system.

These systems make it possible for water to be distributed and slowly percolate the soil without any tendency of soil erosion. An exception to the use of other systems like surface irrigation could be used when rice is grown on terraces on sloping lands.

c. Climate: Climatic factors like wind, especially when it is a strong wind can disturb the spraying of water from sprinklers. Under very windy conditions, drip or surface irrigation methods are preferred.

In areas of supplementary irrigation, sprinkler or drip irrigation may be more suitable because of their flexibility and adaptability to varying irrigation demands on the farm.

d. Water availability: Water application efficiency is generally higher with sprinkler and drip irrigation than surface irrigation and so these methods are preferred when water is in short supply. Efficiency of water usage in irrigating the farm must be taken seriously due to the fact that such water could be costly if it is to be bought or in short supply in where there is scarcity.

e. Water quality: Water quality actually depends on the source of the water and its composition. In a situation where the available water for use contains sediments, the preferred type of irrigation system is surface irrigation.

The reason being that if sprinkler system is used, the sediments may clog the drip or sprinkler irrigation systems.

In addition, if the irrigation water contains dissolved salt, drip irrigation is particularly suitable because less water would be applied to the soil than with surface irrigation method. Sprinkler systems are more efficient than surface irrigation systems in leaching out salts.

2. Type of Crop

This is another major determinant of the irrigation system that should be used in a particular farm or land. The type of crop could be tree crop, shrubs or vegetable crops. Surface irrigation can be used for all types of crops.

In particular, due to the huge sum involved in establishing sprinkler and drip irrigation per hectare, they can be used for high value cash crops such as vegetables and fruit trees. They are seldom used for the lower value staple crops due to the incidence of cost – benefit consideration.

Drip irrigation is suited to irrigating individual plants or trees or row crops such as vegetables and sugarcane. Sprinkler may be suitable for upland rice while flooding system may be suitable for lowland rice.

3. Type of Technology

The level of technology looks at the skill level of the manager or farmer and the technicalities of the irrigation system under investigation. While some methods are simple to use, others are difficult or complicated. The type of technology affects the choice of irrigation method to be chosen or used.

In general, drip and sprinkler irrigation are technically more complicated methods. The purchase of equipment requires high capital investment per hectare.

To maintain the equipment a high level of ‘know-how’ has to be available, Also, a regular supply of fuel and spare parts must be maintained which – together with the purchase of equipment – may require foreign currency.

Surface irrigation systems on the other hand, usually require less sophisticated equipment for both construction and maintenance (unless pumps are used).

The equipment needed is often easier to maintain and less dependent on the availability of foreign currency. The farmer, after his considerations would make up his mind on what best method to use, giving the available resources.

4. Previous Experience with Irrigation

Experience, they say is the best teacher. While some farmers have good and reasonable experience, others may not have.

A farmer would gladly jump and adopt an irrigation system he/she was used to and refuse or reject a system he was not used to before.

The choice of an irrigation method also depends on the irrigation tradition within the region or country. Introducing a previously unknown method may lead to unexpected complications.

It is not certain that the farmers will accept the new method. The servicing of the equipment may be problematic and the costs may be high compared to the benefits.

Level of Technology: Different levels of technologies are required for different types of irrigation systems. Amongst the different types of irrigation systems, basin irrigation system is the simplest of the surface irrigation methods.

Especially if the basins are small, they can be constructed by hand or animal traction. Their operation and maintenance is simple.

On the other hand, irrigation systems like furrow irrigation, with the possible exception of short, level furrows – requires accurate field grading. This is often done by machines.

The maintenance – ploughing and furrowing is also often done by machines. This requires skill, organization and frequently the use of foreign currency for fuel, equipment and spare parts.

5. Required Labour Inputs

The required labour inputs for construction and maintenance of irrigation systems depend heavily on the extent to which machinery is used.

In general it can be stated that to operate the system, basin irrigation requires the least labour and the least skill and that is why if required labour is the item under consideration, the farmer would quickly opt for that system it favours.

For the operation of furrow and border irrigation systems more labour is required combined with more skill. On a normal day, the systems requiring high labour involvement and skill would be turned down by the farmer.

6. Costs and Benefits Consideration

Cost and benefits considerations take into account the different items that constitute costs and the different items that as well constitute benefits as far as the irrigation system he/she wishes to adopt.

At the end of all considerations, the farmer chooses that system that sees to having the benefits outweighing the costs. Otherwise the system would be abandoned.

Source of Irrigation Farming

Report on Irrigation, Soil and Water stated that vast majority of irrigation water use is pumped directly from a water source that may be connected to river, creek, channel, drag line, hole, dam or bore.

The source of the water would also go a long way in determining the type of irrigation system to use in the farm. While some of the source may have sediments, others may have salt in the water.

To this end in view, the farmers decision would be based on the composition of the waterm and the best irrigation method that suits it.

Irrigation Scheduling

Irrigation scheduling is the process by which an irrigator determines the timing and quantity of water to be applied to the crop/pasture. The challenge is to estimate crop water requirements for different growth stages and climatic conditions.

To avoid over or under watering, it is important to know how much water is available to the plant, and how efficiently the plant can use it.

The methods available to measure irrigation scheduling include: (i) plant observation, (ii) feel and appearance of the soil, (iii) using soil moisture monitoring devices; or (iv) estimating available water from weather data.

In summary, the different factors that determine the type of irrigation system to use in the farms were considered in this article. There are basically some factors that actually determine the choice of the farmers in the type of irrigation system chosen to be adopted.

These factors are six namely; natural conditions, type of crops planted, type of technology, previous experience with irrigation, required labour inputs and costs and benefits consideration.

The source of water of the irrigation system was also found to play significant role in the choice of the system to irrigation system to adopt.

This is premixed on the ground that some sources have sediments while others have salt deposits. Irrigation scheduling was as well considered as the process by which an irrigator determines the timing and quantity of water to be applied to the crop/pasture.

This article studied the different factors determining the type of irrigation system to adopt in his/her farm. The factors are six in number and they include natural conditions, type of crops planted, type of technology, previous experience with irrigation, required labour inputs and costs and benefits consideration.

The source of water of the irrigation system was also found to play significant role in the choice of the system to irrigation system to adopt. The timing and quantity of water to be applied to the crop/pasture is an important factor as far as the choice of irrigation system to be considered.