حیدر طایفه رضایی

Grapes is one of the most important horticultural products in terms of cultivation area, economic and high nutritional values. Iran with an annual production of 2.8 million tons, is among the top countries in the production of grape product in the world. However, there are not accurate information on the volume of irrigation applied water and water productivity of this product in Iran. Therefore, this study was conducted with the aim of measurement of applied water at field scale and evaluation of water productivity of grape in vineyards farms at different hubs of this crop production in Iran.

The volume of irrigation water provided by gardeners in 164 vineyards were measured in the provinces of Qazvin, Fars, Khorasan-Razavi, Zanjan, West Azarbaijan, East Azarbaijan, Hamedan, Markazi, Northern Khorasan, and Semnan as hubs of this product. These hubs covered about 80 percent of the irrigated vineyard cultivated areas. In each hub, 1-4 cities with the highest area under vineyard cultivation were selected for evaluation. The measurements were carried out in different irrigation and planting methods, various soils, different salinity of irrigation water and soil and different grape varieties during the growing season of 2018-2019 without interfering with the farmer's irrigation program. The measured values were compared with the net irrigation water requirement estimated by the Penman-Monteith method using the last 10 years meteorological data and also with the national water document values. Crop yield was recorded at the end of the growing season and water productivity was calucated as the ratio of yield to total water (irrigation applied water and effective rainfall). Analysis of variance was used to investigate the possible difference between applied water and water efficiency among the hubs. Data adequacy was assessed by using the method prposed by Sarmad et al. (2001).

The results showed that the average of applied water and water productivity among the hubs were significant at 1% probability level. The applied irrigation water used in the vineyards and water productivity were 6669 m3/ha and 2.63 kg/m3, respectively. Drip irrigation was about 20% effective compared with surface irrigation in reducing the applied irrigation water in the studied vineyards. Water productivity in drip irrigation orchards was essentially the same as surface irrigation and was not statistically significant. The reason was the lack of proper use and utilization of modern irrigation methods.The average net irrigation water requirement in the study areas estimated by the Penman-Monteith method using meteorological data for the last 10 years as well as the national water document were 6645 and 6456 m3/ha, respectively. The range of irrigation application efficiency in the studied vineyards was from 68 to 100 and its average was 89%. Comparison of applied water and net irrigation requirement indicated deficit irrigation due to water shortage in vineyards of most hubs. In total, 31% deficit irrigation occurred in the studied vineyards, which is a threat to soil salinity and destruction of soil structure in long-term. Grape planting method had a significant effect on reducing the applied water, increasing grape yield and consequently water productivity. Scaffolding method had a positive and significant effect on all studied indices in comparison with the crawling/reptile planting method. It caused a decrease of about 15% in applied water, an increase of 41% in yield and 37% in crop water productivity.

Due to the fact that vineyards are faced with deficit irrigation and water stress, training the farmers about the accurate and scientific methods of deficit irrigation in the vineyards can be effective to reduce the destructive side effects of water stress. Due to the widespread use of surface irrigation in the vineyards, training and application of methods to improve surface irrigation performance (evaporation reduction methods, using low pressure methods such as gated pipes, mulching, etc.), to increase irrigation efficiency and to reduce irrigation water applied is recommended. Changing traditional planting methods from crawling/reptile to scaffolding and surface irrigation (qana) to furrow, in addition to reducing evaporation, are the effective ways to increase the yield of vineyards and water productivity.

Low rainfall and its poor distribution in the West Azerbaijan province have hampered agricultural production in dry-land. One of the important solutions in this regard is converting rainfall into runoff. In this study, a field experiment in Khoshalan village of Urmia on grapes in rainfed conditions with supplementary irrigation and rainwater harvesting was carried out in a split-plot design based on randomized complete blocks for six years from 2000 to 2006. The first four years were for seedlings of plants, and recording of yield was possible in 2005 and 2006. The three factors studied include fertilizer application factor in 30 and 70% of the usual recommendation for irrigated cultivation, watershed area factor in areas of 12, 20, and 30 m2, and runoff surface status factor including normal traffic, plastic cover, and paving stones. In this study, the benefit is calculated based on the cost and income of 2019. The results showed that with increasing fertilizer consumption, yield decreased from 1755 to 1461 kg/ha, and benefit decreased from 81.2 to 46 million rials. This result indicates that under semi-dry conditions, fertilizer, cannot be consumed in large quantities. With decreasing watershed area, yield and benefit increased from 1018 to 2451 kg/ha and from 6.2 to 148 million rials, respectively. Plastic with 2208 kg/ha and 113.6 million rials had an increase in yield and profit of 54 and 86% compared to the control. Also, paving stones compared to the control, experienced 1 and 49% yield reduction, and profit respectively. According to the results of this study, an area of 12 m2, with plastic cover with 70% of the usual fertilizer recommendation for irrigated cultivation, increases the yield of rainfed grapes.

To evaluate the effect of irrigation on seed yield and water productivity of three common canola hybrids including: Okapi (T1), Elite (T2) and Milena (T3) in the strip-plot statistical design with three repeats for 2004-2005 and 2005-2006 a field experiment was conducted in Miandoab agricultural and natural resources research center. To extract production and water productivity functions, eight treatments of different irrigation levels with IP1 to IP8 symbols including 120, 110, 100, 90, 80, 80, 70, 60 and 50% of water requirement calculated by the Penman Monteith FAO method was considered. The results showed that the production functions in T1, T2 and T3 hybrids have a correlation of 0.98, 0.98 and 0.97. By extracting the productivity functions, it was observed that the amount of water productivity decreased under severe stress conditions and increased with increasing water content. If deficit irrigation is required, IP4 treatment is recommended due to the highest seed yield (average seed yield equal to 3758.5 kg/ha for two years). The results of statistical analysis of studied parameters showed that with 10% reduction in water consumption, benefit decreased 7.83% in the first year and 3.44% in the second year. T2 and T1 hybrids had the highest yield in the first and second years, respectively, and the yield was higher in the second year than in the first year. The reason for this is the increase in temperature and more radiation received in the second year. To maximize productivity, IP4 and T2 hybrid are recommended.

This study was carried out in 2012 to determine the total irrigation efficiency and real hydro module of Nazlouchai plain in Urmia, using water balance method. In addition to field experiments, we used data gathered from previous documents and related analytical conclusions. Field experiments conducted in 14 farmer’s fields. The result showed that water application efficiency varied from 55.4 to 78.8%. Water distribution efficiency varied from 75 to 94% and water conveyance efficiency was 66 to 92%. Total efficiency of traditional network estimated 44% and net water requirement of cropping pattern of the plain based on Penman-Monteith method calculated about 4930 m^3/ha, thus gross water requirement of cropping pattern was 11204 m^3/ha. The traditional irrigation network of Nazlouchai plain, with 29050 hectares of land, is located in the lower part of Nazlouchai basin. Annual water withdrawal from Nazlouchai river estimated about 128 Mm^3 and differential of input – output of the plain groundwater estimated about 13 Mm^3 annually. Water balance of Nazlouchai plain was negative with 29 Mm^3/year shortage. Estimation reveald that water consumption of Nazlouchai plain was 170 Mm^3 and irrigation actual hydro module of the plain 5838 m^3/yr/ha. The results showed that water efficiency of Nazlouchai plain in agricultural activities was about 85%. The results of this study showed that the actual rate of agricultural water consumption was lower than what was declared, based on national efficiency; the figures announced for water productivity in agricultural production should be reviewed too.