The effect of drip irrigation system (tape) on water consumption management in the main centers of melon production in the country

Melon, with the scientific name Cucumis melon L, is an annual plant belonging to the Cucurbitaceae family (Mas, 1986). Melon is one of the most important products, which is rich in absorbable vitamins and minerals needed by the human body. According to the statistics of the World Food Organization (FAO), Iran with the production of 1731 thousand tons of melons in 2018, was the third producer after China (with the production of 12727 thousand tons) and Turkey (with the production of 1754 thousand tons), and the countries of India, Kazakhstan and America are ranked 4th to 6th in the world with 1231, 894 and 872 thousand tons respectively. Improving water productivity in crop production is necessary due to limited water resources in Iran. According to the surveys conducted on the volume of irrigation water (water applied) or the water given by farmers to melon cultivation, there are no accurate and reliable statistics in the country, and no relatively accurate measurement or estimation has been done in the country. On the other, melon cultivation is important in Iran, so it is necessary to study the volume of applied water in production of this product. In iran, development of pressurized irrigation systems has been one of the main programs in developing agricultural sector in the past few decades. Assessing the effects of these systems can be important in increasing of water ues management, national policies and planning. In this article, based on the field data of the research, it is tried to explain the amount of water used and water productivity of melons in the country and the effect of irrigation management (traditional and modern) on the amount of water given to melons.

In order to determine the volume of water used, yield and water productivity of melon crop with the management of farmers in Khorasan Razavi, Fars, Khuzestan, Semnan and Sistan and Baluchestan provinces in calendar year of 2020, 138 melon farms were selected. In these farms, the volume of applied water by farmers was measured. Water irrigation applied (water used) were compared with the net irrigation requirements estimated by the FAO Penman-Monteith method using meteorological data from the last 10 years, as well as the values of the national water document. In this study, the method of analysis of variance is used to investigate the possible differences in yield, applied water and water productivity in melon production. Data adequacy was assessed by using the method provided by Sarmad et al. (2001). Then, the effect of drip irrigation method on applied water, application efficiency and physical water productivity was investigated in the study areas.

The results showed that the differences in yield, applied water and water productivity indices in melon production were significant in selected provinces (P ≤ 0.01). The average weighted of yield, applied water and water productivity in Iran were 24962 kg / ha, 7117 m3/ha and 3.4 kg / m3, respectively. The total water for irrigating melon in Iran was estimated at 570.8 million cubic meters. The average yield of melon in furrow and tape irrigation was 20,954 and 24,500 (kg/ha), respectively. In other words, the average yield in tape irrigation method was 14.5% more than furrow irrigation method.The average volume of water in furrow and tape irrigation methods was 7940 and 6073 (m3/ha), respectively. The average volume of irrigation water in the tape irrigation method showed a decrease of 23.5% compared to the volume of irrigation water in the furrow method. The average water productivity in furrow and tape irrigation methods was 3 and 4.3 kg/m3 per hectare, respectively. The average water productivity in tape irrigation method showed an increase of 30% compared to the average of furrow irrigation.

The results of this research showed that tape irrigation method can improve yield, water consumption management and water productivity for melon. Also, the results of this study provide useful information on applied irrigation water management indicators in melon production to managers and water decision makers within Iran. The results of this research show that the use of drip irrigation systems (tape irrigation system) for melon cultivation in the country (and other row crops) can increase water productivity and reduce water consumption in the agricultural sector. However, the operation management of these systems in the country has a relatively long distance from the desired level