**2.4 How are the washing needs of the plants that are added to the irrigation water determined to help achieve the appropriate salinity ratio for the plant?**

This is done by the following equation:

Laundry needs = salinity of irrigation water (mm) × (100/plant tolerance rate of salinity).

Example: The wet needs of potato plants irrigated with water with an electrical conductivity of 1 mm/cm at 25°C are required [42].

The ECe, where there is no crop shortage, is 1.7 millimhos.

Solution: washing needs of potato = 1 × (100/1.7) = 59%.

In order to avoid any shortage in the potato crop, which is infused with salted water 1 ml/cm, it is necessary to increase the amount of water needed for each irrigation [48]. This is 59% as washing needs to wash the accumulated salts in the area of root spread and drain away from the root zone.

#### **Figure 1.**

*The ratio between mean of soil salinity and amount of gypsum annually adding. (1) 4 mm: 0.75 ton/fed; (2) 6 mm: 3 ton/fed; (3) 10 mm: 6.5 ton/fed.*

*Irrigation - Water Productivity and Operation, Sustainability and Climate Change*

to coexist with the permitted limits of growth.

wells by choosing irrigation method.

**2.3 Salinity ratio suitable for agriculture**

salinity, and researchers were interested in developing ways to reduce the proportion of salts in water [66–69]. In this report, we offer you several golden tips, which are the summary of experience and science in dealing with the problems of salinity in your farm or field: It is not wise for farmers in saline lands to wait to overcome the full salt problem before starting the commercial production cycle. Rather, it is wise to coexist with the problem and gradually overcome it by preparing the root region

Soil permeability relationship with irrigation capacity of saline water: Land with good permeability is tolerated by irrigation with saline water up to 3000 ppm without the accumulation of salts or causing a problem [70]. Poor soil permeability is precipitated by water salts even if salinity is 200 ppm due to the accumulation of salts over time [71]. Calcium nitrate and urea were used as an alternative to nitrate as a source of nitrogen and calcium. Fertilizers containing sulfate, such as potassium sulfate, magnesium, manganese, and zinc, were used. Sulfuric acid is usually used through the irrigation operation by the (fertigation) techniques, whereas nitric and phosphoric acids are used with the organic matter during preparation for each new crop.

To reduce the harmful effect of salts in the well water, we must modify the ionic structure by adding some chemicals [72–74], which helps to precipitate the harmful constituents of carbonates and bicarbonates. The following relationships should also be known: sodium absorption ratio (SAR)/electrical conductivity (EC)/leaching ratio (LR), especially when using saline water, so that the soil does not deteriorate and decrease production. How to reduce the effect of water salinity on crops? To overcome the problem of salinity and achieve the highest productivity in the presence of salts, irrigation periods with the installation of long washing irrigation to remove the salts from the root area must be rounded. If the proportion of sodium in the irrigation water is to be considered, the approximate percentage of calcium or magnesium must be adjusted by adding calcium throughout the year. The best source of calcium here is the agricultural gypsum because of its multiple benefits, which we will talk about in a separate report. Reducing salinity of

When sprinkling and high-water salinity, water droplets should be observed to be large and not misty. Irrigation is done at night so that the evaporation process decreases, and the salts are deposited on the leaves of the plant. Frequent drip irrigation without changing the lines or completely immersing the entire land once or twice a year will exacerbate the problem of salinity in the soil. In addition, irrigation of agricultural banks that have drainage water for farms and adjacent fields is the most dangerous to the future of the soil and will not be able to reduce the deterioration and desertification in the future. The large number of composts with fertiliza-

The problems of soil and water salinity are endless, and we have asked hundreds of questions about the best methods to be relied upon in agriculture. In the next report, we will review together important information on this subject, with an indication of the salinity ratio suitable for agriculture [75, 76]. Possible agricultural methods to avoid and reduce salinity damage based on nonreclaimed saline lands can be utilized as follows: Agriculture is on high lines with agriculture in the lower half of the miles because the salts bloom at its peak. The same method can be followed when farming on the terraces with the work of a small pyramid rise in the center of the terrace in order to bloom salts. Winter crops are preferred where the salt damage is less than that in the summer crops, and planting is preferred by seedling [57]. Drip irrigation helps to collect salts away from plants, so that the soil is washed from the accumulated

tion of ammonium nitrate causes the salinity of the soil to be increased.

**62**

It is noted that these washing needs calculated in the example are very high and may not be followed, especially because of the lack of irrigation water or the absence of good drains [40].

Therefore, the tolerance of the plant for salinity is calculated on the basis of the ECe score, where a 25% reduction in yield occurs in case of potatoes at ECe = 3.8.

Thus, the washing requirements of potato = 1 × (100/3.8) = 26% more than the amount of water assessed for each irrigation as washing needs to wash the accumulated salts in the area of spreading the roots and away from them. Commercial sulfuric acid is injected with irrigation water at a rate of 2 l per feddan per week for a month. This removes the salts from the roots and removes them on the surface of the soil, thus improving the growth of the plants. Some natural compounds and raw materials are used for the treatment of salinity.

### **2.5 Magnetic water to overcome saltwater and make it suitable for agriculture**

Many countries in the world, including the Arab countries, suffer from the loss of water of the river. Therefore, desalinated saltwater is available from seawater and groundwater. In fact, there are several techniques to desalinate salty water, including the following:


There is an excellent way to decompose using magnetic separation. This efficiently removes up to 99% and more. This is because of the salinity of the water (the presence of positive ions and other negative ions), but these ions do not attract toward the magnet, so scientists thought of the physical center attracted by the negative ions and positive ions and attracted them to the center of magnets and this is called Feret Fe3O4, which is thrown in the saline water to be reanalyzed and attracted to the negative and positive ions by the magnetic field, which penetrates water for purifying it. Electrical dialysis has been commercially known since the 1960s, 10 years before reverse osmosis. The cost is effective for desalination of saline water wells and makes the decision for attention in this regard. The electrolysis technique is based on the following general principles. The electrolysis unit consists of several hundred pairs of cells connected to each other by electrodes called a compound of membranes. Feeding water flows simultaneously through passages through the cells to provide the flow of desalinated water as the concentrated water passes through the compound.

Based on the design of the system, it is possible to add chemicals in the compound to reduce the voltage and prevent the formation of crusts. Feed water must be treated from the outset to prevent substances that sweat membranes or block narrow channels in cells from entering the membrane compound. Feed water is rotated through the compound with a low-pressure pump to overcome water resistance as it passes through narrow passages. A rectifier is often installed to convert the oscillating current into a direct current supplied to the electrodes from outside

**65**

*Performance of Water Desalination and Modern Irrigation Systems for Improving Water…*

the membrane complexes. Final treatment includes water stabilization and processing for distribution, which may include the removal of gases such as hydrogen

Land processing and settlement are important factors in irrigated agriculture, especially when using seawater in irrigation. As is known in irrigated agriculture, salts tend to accumulate and redistribute in the soil sector, where salinity occurs in the field. For example, high areas are increasingly accumulating salt. Therefore, the land should be divided into pieces that may be different in size, but attention should

Many soil species have been successfully used in clay land to sand dunes and it is important that the soil is good for natural drainage. It is therefore necessary to plow the soil to a depth of 1 m to improve drainage especially in heavy land. When sandy soil is compressed under the surface layer, it must be prepared in terms of deep

Although many halophytes bear high ground water, interest in drainage is an important factor in resisting salinization. In the case of heavy land, shallow banks must be made in the form of a letter V, at a depth of half a meter, and in dimensions of 10–20 m, to be drained into deep drains and can be drained through water pumps

The surface of the desert sea has a shallow reservoir of groundwater saline that extends to several kilometers of sea level. However, irrigation by seawater will cause damage to any groundwater reservoir. Therefore, hydrological studies should be carried out for the aquifers of the area to be used for irrigation by seawater (depth quality—quantity). The hydrophysical characteristics of the soil must be studied. If the site is located next to a mountain range parallel to the coast as in the case of the Red Sea, the fresh water that collects under the mountain valley or on the sandy

One of the most important restrictions on the use of seawater to produce halophytes is how to manage water. It is necessary to prevent the accumulation of salts in the rhizosphere. This is a condition other than freshwater irrigation where irrigation is based on the level of soil moisture. In traditional irrigation conditions, irrigation occurs when the soil moisture is reduced to 50%. However, in the case of seawater irrigation and the lack of ground moisture to 50%, the salinity level in the root zone is twice the salinity level of seawater, which has a severe effect on the plant. For most halophytes, it was found that the moisture deficiency should not exceed 25% to reduce the chance of increasing salt concentration between the irrigation in the soil sector. It is also necessary to add washing needs about 25% or more in each rye

Short irrigation and high-salt washing are therefore key to achieving success and achieving high yields of halophytes using seawater. For example, in the case of sand dunes or sandy beaches, irrigation should be carried out regularly on a daily basis during the summer season, while in sandy soil, which can't retain enough water,

The most important factor required for the establishment of a seawater farm is that there is a source available, close to seawater and at a low cost. The cost of seawater supply is the largest investment in this type of project, and it exceeds the other factors such as irrigation method, quantity of water required, and agricultural practices required.

irrigation can be done every day and every 10 days in the winter season.

*DOI: http://dx.doi.org/10.5772/intechopen.87010*

sulfide or alkaline modification.

back into the sea.

shoreline must be maintained.

to wash the salts and expel them below the root area.

**2.7 Planning the establishment of a seawater farm**

**2.6 Selection of soil preparation site**

be paid to settling the soil surface in one piece.

plowing, surface tillage, settlement, agriculture, and irrigation.

the membrane complexes. Final treatment includes water stabilization and processing for distribution, which may include the removal of gases such as hydrogen sulfide or alkaline modification.
