Dr. Ghazwan Husam Tawfeeq

Irrigation can be defined as the process of adding water to the soil when the amount of rain is insufficient to meet the needs of plant growth. There are many sources of water available for the irrigation process, some of which are superficial, such as rivers, tributaries and streams of water springs, or they are groundwater that is drawn by pumps to the surface.Historically, evidence indicates that humans, about 10,000 years ago, worked to devise agricultural methods to increase the agricultural area and this is to meet their need for food. Such changes may have occurred for the first time in the hills of northern Iraq and Syria. These changes came either as a result of the increase in human growth in those areas, or that the floods of the Tigris and Euphrates in those periods led to the deterioration of the fertile lands surrounding their basins; which led to finding ways and means to take advantage of the surplus waters of the rivers in the beginning. From here, we find in the ancient clay figures and stone codes what indicates the construction of water channels to drain overflow water and distribute it on beside lands. Accordingly, the idea of ??farming for multiple crops arose and developed, and thus the area of ??land that was cultivated increased to meet the human need for food at that time.

In the progress of time and up to the present times, the idea of transferring and distributing water on fields to be cultivated had developed, from surface irrigation methods to the use of mechanization in irrigation. The idea of using water wheels is one of the mechanical methods for transporting irrigation water from the source and pouring it into a canal. History indicates that water wheels were used more than 4000 years ago. It is interesting that this method is still used since that time to this day in Iraq, Syria, the Netherlands and several countries. But thanks to God, he taught man what did not know. Centre pivot sprinkler irrigation method is arguably inspired by the idea of a water wheel. Pivot irrigation systems are the most popular sprinkler irrigation systems in the world due to their high efficiency and ability to irrigate various types of soils, flat and uneven lands. The history of centre pivot irrigation systems began in Nebraska in the 1950s, and there are now hundreds of thousands of centre pivot irrigation systems in the world. In addition, there are largely agricultural areas where winged sprinkler irrigation and solid sprinkler irrigation systems are used.

There are irrigation systems other than sprinkler, where most vegetable crops and even fruits have become irrigated by drip irrigation systems. There is also a method of irrigating plants on lines, but by buried pipes. From this it can be recognized the diversity of irrigation methods depending on the type of crop, area, soil and season. The cost of mechanized irrigation may initially be higher than the cost of traditional irrigation systems such as streams and basins, but with time it has proven its worth in saving water at high rates from 80 to 95% compared to the old regular methods. On the other hand, many international studies and United Nations statistics indicate an increase in population and the attendant increase in demand for food. The use of mechanization in irrigation and agriculture to provide sufficient food for human needs has been in line with the ongoing human growth. However, agricultural crops mainly depend on sufficient water for their growth. Here it should be noted that the sources of water suitable for irrigation are almost constant over time, or in fact have become less than they are as a result of consuming a percentage of it for people's daily needs. Despite the widespread use of mechanized irrigation, it does not replace the lack of water consumption in agriculture, and this is a dangerous indicator in reality.

Therefore, many studies have arisen at the level of developed and developing countries in developing solutions to this problem. Including what revolves around reducing pollution and reducing global warming, some studies seek to find drought-resistant crop varieties. But the most interested was to find more technical ways than it is now to save water when farming. Through the results of scientific research, the means and methods of irrigating grain and vegetable crops have diversified. Farmers have accepted the idea of ??using recycling water, for example, after filtering and reusing it for irrigation purposes, in the manner of sprinklers or drip systems. Using ??hydroponics with small or large basins to produce vegetable crops even for local level for some countries or for the purpose of export has been successful.  The idea of ??fogging irrigation also emerged for some horticultural crops or flowers.

The technology did not stop to this extent, in many countries, satellite images were relied on to determine the areas suitable for agriculture and the availability of water there. Rather, pivot sprinkler irrigation systems have now relied on the presence of small-sized ground sensors scattered throughout the field to indicate the extent of soil moisture, and through a simple program, the sprinkler system can be turned on or off remotely.

Moreover, and to reduce the pollution that occurs to the environment, solar panels have been relied upon to provide sufficient energy to operate water pumps, drip or sprinkler irrigation systems. Several studies have resulted in the production of water suitable for irrigation, which was originally saline water. The idea of ??desalinating water by traditional means has developed into the production of high-tech factories to produce thousands of litters of water, sufficient to irrigate agricultural areas using sprinklers or drippers. This is what we find in the Arab Gulf states and some other countries.

In another field, many countries of the arid and semi-arid regions have adopted the water harvesting system. It depends on collecting rainwater in basins scattered in the desert, storing it and consuming it in agricultural fields, and watering animals.

From this, suitable water for irrigation is the greatest challenge for food production in the twenty-first century. The competition of the different sectors for water has become a strong impact on the share of water within the agricultural sector. Therefore, if the means of irrigation economics are not available through mechanization and other smart ways to save water, agriculture will be the biggest loser and face an agricultural water crisis in the coming years.