The inefficient use of water resources is one of the main factors that limit the sustainable development of irrigated agriculture in Uzbekistan. One way to solve the problem is through the use of a drip irrigation system.

A small hole which has changed the world

Drip irrigation was developed and implemented for the first time on an industrial scale, as an independent type of irrigation in Israel in the early 60s. Positive results were obtained within a short time, and the system’s introduction in Israel led to its rapid adoption in many countries around the world. Drip irrigation is based on the inflow of water in small doses to the root zone of plants. The quantity and frequency of the water supply is controlled in accordance with the needs of plants. Water is supplied evenly to all the plants in the same amount, exactly as much as the plant needs, without unnecessary flooding of the soil and water loss. Moreover, huge water losses due to evaporation during the transportation of water to the plant are decreased.

The system during the installation in a field

However, land users in Uzbekistan have not yet investigated this technique. There are many reasons for this, the main one being that farmers believe that a drip irrigation system will be expensive and complex. Also, it is recognised that the quality of irrigation water, including its turbidity and clayiness, can limit the use of drip irrigation. However, the farmer Boltabayev from the Namangan province has debunked these myths through his personal example on his own land. Using a tubular drip irrigation system, Boltabayev has harvested 38 centners of cotton from one hectare. His neighbours from the same area, meanwhile, have harvested 15 to 21 centners per hectare. In his case, Boltabayev used three times less water, 50 per cent less fertilisers, and he spent 58 to 60 litres less fuel per hectare for his farm machinery, when compared to his neighbouring farmers.

This is a view of how a field looks like with a low productivity class, high content of sand and stones.Here the farmer Boltabayev started introduing a system of drip irrigation

And this is the same field with cotton. A crop capacity has grown significantly

Modern drip irrigation systems can be used for the cultivation of many agricultural and horticultural crops, and have a number of advantages. These include:

- Significant water savings - Since only the root zone of plants is moistened with a drip irrigation system, evaporation losses are significantly reduced. Consequently there is no loss of peripheral water flow. In the case of drip irrigation, the space between rows, referred to as ‘Aryks’, remain entirely dry. This can be compared to conventional irrigation, in which water is usually delivered to plants via the Aryks. The total water savings generated through a drip irrigation system is 11.7 million m³ per one hectare of cotton, 6.6 thousand m³ per one hectare of wheat, and 11.4 thousand m³ of water per one hectare of other crops;

- Significant savings of energy, labour, petroleum, oil and lubricants (POL) and other materials – Water for irrigation is usually supplied from canals to fields via pumps. Drip irrigation requires less water, which means that pumps are used less, and less electricity or other forms of energy is used (for example diesel fuel) for operating pumps. The use of drip irrigation has resulted in significant savings in labour costs, of up to 1.3 to 3 times. Up to 60 litres of POL per one hectare of cotton are saved each vegetation period;

- Savings of fertiliser by 30-40 per cent - In the case of usual irrigation, 850 kg of nitrogen fertiliser, 150 kg of phosphorus and 100 kg of potassium chloride are used for 1 hectare of cotton fields. However, with the use of drip irrigation, 250 kg of nitrogen, 150 kg of phosphorus and 50 kg of potassium are used for 1 hectare. In this case, the fixation of mineral fertilisers is 90 to 95 per cent, compared to only 30 to 35 per cent with conventional irrigation. Dissolved fertilisers are applied directly to the root zone with water during irrigation, where a rapid and intense absorption of nutrients takes place. Consequently, the use of drip irrigation provides the most effective way of applying fertilisers in the arid climate conditions;

- Higher productivity and product quality – The earlier ripening of crops has been observed when drip irrigation systems are used. Due to the exact application of moisture to the roots of plants, and the more effective absorption of fertilisers, the yield increase by 30 to 70 per cent is guaranteed, when compared with conventional irrigation;

- Lack of secondary salinity – As drip irrigation does not require the construction of drainage systems, underground waters and salt do not rise, and the structure of soil can be maintained. This type of irrigation allows plants to be grown in moderately-saline soils, with the use of slightly-salted water for irrigation. With drip irrigation, the intensive desalination of salts takes place near the droppers. The accumulation of salts around the edges of droppers does not have too much impact on the development of plants. Water and nutrients are absorbed by the part of the root system from the leached zone of the soil;

- The possibility of irrigating strongly-intersected plots of the ground surface with different water infiltration of soils – In a drip irrigation system, a system of tubes or tapes is located at the base of plants, for example on the beds themselves. Drip irrigation allows the use of irrigation on slopes or areas with complex topography, without special facilities or the transfer of soil. The use of drip irrigation on the slopes does not pose any threats of erosion. In addition, drip irrigation is very beneficial to the adyr lands, where gaps and holes can appear with ordinary irrigation, and water can potentially go deep into the ground without irrigating plants;

- Easy operations in the inter-row spacing – With conventional irrigation the inter-row spacing is filled with water, which makes the movement of vehicles and people difficult. With drip irrigation the canals remain free from moisture and this allows better tillage, spraying and harvesting at any time, regardless of irrigation, as the soil in inter-rows remains dry throughout the vegetation period;

- Fewer weeds – There are fewer weeds in fields that use drip irrigation, in comparison with those using other methods of irrigation, since the water is supplied only to the root systems of plants and does not irrigate the surrounding land around. Root systems develop faster with drip irrigation than in the case of other methods of irrigation. The bulk of plant roots are concentrated in the area of drip trays, and consequently the root system becomes more fibroid, with an abundance of active root fibrils. The intensity of water use and nutrients increases as a result.

On the basis of these initiatives to implement drip irrigation systems in the Namangan province, a comparative cost-benefit analysis of introducing drip irrigation for cotton, wheat and other crops (in particular apples - see table) was made. The calculations are given for a minimum of 10 hectares for each crop, as it is at this size that minimum economies of scale can be achieved, when the investments begin to pay off. Current prices for 2013 are used, which of course may change over time.

The value of investments for the installation of drip irrigation systems has been calculated on the basis of the relevant price list of the manufacturer of drip irrigation systems in the Namangan province, particularly at the production plant at the ‘Jamoliddin Sardor Hamkor’ farm enterprise. Drip irrigation systems are most expensive when they are used with wheat, at 91.6 million soums per 10 hectares, followed by cotton at 88.4 million soums. The cheapest and the best is the system of drip irrigation for 10 hectares of garden, at 50.4 million soums.

The calculation of benefits is as follows (for one hectare):

- Energy costs are significantly reduced for all crops, as a result of a significant reduction in the time dedicated to irrigation and the use of pumps for pumping water. As a result, drip irrigation can reduce energy costs by 499 million soums per one hectare of cotton, 317 thousand soums per one hectare of wheat, and 320 thousand soums per one hectare of other crops, per season;
- The cost of diesel fuel and agricultural activities are reduced, especially for cotton, as cotton production consists of more agricultural activities when compared to wheat or other crops. Drip irrigation will save more than 100 thousand soums per one hectare of cotton on diesel fuel and 85 thousand soums peer one hectare of cotton for farming activities annually;
- Due to the effective introduction (through the system) and fixation of mineral fertilisers, with the use of a drip irrigation system, the cost of fertilisers reduces by 114 thousand soums per one hectare of cotton and 37 thousand soums per one hectare of wheat annually;
- The cost of labour decreases by 200 thousand soums per one hectare for all crops mentioned above;
-The forecasted increase of yield is quite substantial, averaging 40 per cent for all crops.

Annual benefits have been estimated based on the average crop yields and average prices:

- Water saving for all crops per year, particularly 11,760 m³ of water per one hectare of cotton, 6,600 m³ of water per one hectare of wheat, and 11,455 m³ of water per one hectare of other crops;
- According to the decree of the President of the Republic of Uzbekistan # УП-4478 of the 24^th of October, 2012, legal entities that have adopted drip irrigation systems will be exempt from the payment of the single tax for five years, for the part of the land where drip irrigation is used (changes to the tax code are not in force yet but are expected in 2013). The approximate calculation of savings from tax privileges is 81 thousand soums per one hectare, for each crop, per year;
- The payback period is the ratio of investment to the annual general benefits. It is estimated that investments in drip irrigation for cotton will be paid off within slightly more than three years and for wheat within four years. The most profitable investments will be made for the garden crops, for which the payback period is slightly less than two years.

Drip irrigation system are consequently beneficial not only in terms of the care of natural capital, including savings of water resources, the improvement of land soil, energy and fuel savings, and reduced emissions. The systems are also beneficial in economic terms, not only for garden crops but also cotton and wheat, in the medium-term view.

D. Niyazmetov, I. Rudenko

NGO ‘KRASS’
Contacts: The ‘Jamoliddin Sardor Hamkor’ farming enterprise
Director: Farmer Abdulvohid Jamoliddinovich Boltabayev
Tel.: + 99893 495 11 98; +99894 274 43 83
E-mail: abdulvohid.b@mail.ru
Address: 17, Yangi Bahor str., mahalla ‘Umid’, CBO ‘Uychi’, Uychi district, Namangan province, 160800, Uzbekistan
Table. Cost-benefit analysis of the introduction of a Drip Irrigation System, compared to the conventional method of irrigation.

All calculations were done for 10 hectares