نوع مقاله : مقاله پژوهشی
نویسندگان
1 بخش تحقیقات فنی و مهندسی کشاورزی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان اردبیل (مغان)، سازمان تحقیقات، آموزش و ترویج
2 بخش تحقیقات فنی و مهندسی کشاورزی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان خراسان رضوی، سازمان تحقیقات، آموزش و ترویج کشاورزی،
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Reliable estimates of the seasonal applied water and irrigation performance assessment indicators under current irrigation and farm management are perquisites for improving water resources management. In this study, seasonal applied water and irrigation performance assessment indicators of winter barley were studied by monitoring 25 farms under actual conditions, in Ardabil Province (Ardabil, Namin, Nir and Kosar counties), Iran, during the growing season 2020-2021. The seasonal estimates of the net irrigation requirement during the growing season 2020-2021 and its 10-year average ranged from 476 to 652 mm and from 403 to 535 mm (with a mean of 530 and 449 mm), respectively, over the study farms. The total sum of seasonal applied water and effective precipitation (I + Pe) and the barley grain yield ranged from 266 to 716 mm and from 0.14 to 4.07 ton ha-1 (with a weighted average, WA, of 475 mm and 2.33 ton ha-1), respectively. As a result of limited irrigation water availability, 3-91% (with a WA of 52%) of the intended yield of irrigated barley in the study area (4.5 ton ha-1) was achieved. Physical and economic water productivity indicators were significantly (P < 0.05) affected by farmer's skill level, crop rotation, type of irrigation water source, and irrigation method. The results indicated that farms with surface water supply showed the highest vulnerability to drought periods. Improving the on-farm water management flexibility and mitigating the negative impacts of hot and windy days during the grain filling stage can improve water productivity indicators in the study area.
کلیدواژه‌ها [English]
EXTENDED ABSTRACT
Intensive and extensive expansion of irrigated agriculture along with increasing urban and industrial water demands have strengthened the concerns of competing users over limited water resources in arid and semi-arid areas, which are fragile and already stressed. In this regard, reliable estimates of the seasonal applied water, I, and irrigation performance assessment indicators under current irrigation and farm management are essential to provide a rationale for decision-makers to formulate adequate water management policies. The objective of this work was to assess the seasonal on-farm irrigation performance of winter barley (Hordeum vulgare L.) under actual operation conditions by monitoring 25 farmer farms (including 22 and three farmer farms with surface and solid-set sprinkler irrigation systems, respectively) in Ardabil Province (Ardabil, Namin, Nir and Kosar counties), Iran, during the growing season 2020-2021.
The collected on-farm data included soil texture/salinity, irrigation schedule/depth, irrigation water salinity, crop development stages, crop yield, and field economic data. Weather data were obtained from the nearby synoptic sites, including Ardabil (lat. 31⁰20’ N, long. 48⁰40’E) and Firuzabad (lat. 31⁰20’ N, long. 48⁰40’E). Crop water requirement, ETc, was determined by the FAO Penman-Monteith model. Effective precipitation, Pe, was determined, using the USDA-SCS method. The Doorenbos and Kassam function was used to estimate actual evapotranspiration (ETa). To assess the Irrigation performance in the study fields, the following nine performance indicators were chosen: relative rainfall supply (RRS = Pe / ETc), relative water supply (RWS = [I + Pe] / ETc), relative irrigation supply (RIS = I / [ETc - Pe]), Israelsen's application efficiency (AE), crop yield ratio (CYR, the ratio of actual to intended crop yield), water use efficiency (WPET), irrigation water productivity (WPI), total water (irrigation + effective precipitation, I + Pe) productivity (WPI+Pe), and economic water productivity (WP$).
The seasonal estimates of the net irrigation requirement for barely, In, during the growing season 2020-2021 and its 10-year average ranged from 476 to 652 mm and from 403 to 535 mm with a mean of 530 and 449 mm, respectively, over the study farms. The total applied water (I + Pe) and the grain yield ranged from 266 to 716 mm and from 0.14 to 4.07 ton ha-1, with a weighted average, WA, of 475 mm and 2.33 ton ha-1, respectively. The range of RRS, RAW, and RIS indicators were 0.10-0.16, 0.46-1.18, and 0.39-1.21, with a WA of 0.12, 0.73, and 0.70, respectively. CYR ranged from 0.03 to 0.91 (with a WA of 0.52). These results indicate that all study farms experienced varying degrees of deficit irrigation. The mean Israelsen's application efficiency (AE) over initial, development, mid-, and late-season growth stages were obtained 9, 82, 97, and 100%, respectively. The range of WPET, WPI, and WPI+Pe were 0.83-1.14, 0.05-1.38, and 0.04-0.99 kg m-3, with a WA of 0.96, 0.59, and 0.48 kg m-3, respectively. WP$ range from -14.35 × 103 to 59.12 × 103 Rial m-3 with a WA of 21.47 × 103 Rial m-3. WPI, WPI+Pe, and WP$ indicators were significantly (P < 0.05) affected by the farmer's skill level, crop rotation, type of irrigation water source, and irrigation method. Farms with surface water supply showed the highest vulnerability to drought periods, compared to farms with well and multi-source combined (both surface and well) water supplies. Improving the on-farm water management flexibility and mitigating the negative impacts of hot and windy days during the grain filling stage can improve water productivity indicators in the study area.
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