مديريت آبياري دركشت برنج با استفاده از سامانه هاي قطره اي- نواري سطحي و زير سطحي در شرايط مصرف سوپرجاذب

Nowadays, considering the limitation of water resources an‎d the increase in population, the role of research an‎d modern technologies in reducing water consumption in agriculture cannot be ignored. Among the most important of these methods is the use of drip irrigation systems. These systems supply the water required by plants with high efficiency an‎d significantly reduce losses caused by deep percolation an‎d evaporation. In addition, the use of water-absorbing an‎d water-retaining materials in soil, such as superabsorbents, can play an important role in water retention an‎d, consequently, increase the irrigation interval of plants. Therefore, it seems necessary to investigate the feasibility of applying these methods for important an‎d strategic agricultural crops, such as rice, in order to determine a roadmap an‎d future perspective. Rice (Oryza sativa L.) is one of the most important crops an‎d the main food for more than half of the world’s population. Considering the shortage of water resources in the country, traditional rice cultivation faces limitations. This study was conducted with the aim of extending modern irrigation methods in the presence of superabsorbents for direct seeded rice at the research farm of Isfahan University of Technology (lavark), located in Najafabad, during the years 2019 an‎d 2020. Field experiments in this study were implemented in split-split plots based on a ran‎domized complete block design over two consecutive years. The pressurized irrigation system was established in two modes: surface drip-line irrigation (pipe spacing 50 cm, emitter spacing 20 cm, emitter flow rate 3 L h⁻¹) an‎d subsurface drip irrigation at 30 cm depth (pipe spacing 50 cm, emitter spacing 25 cm, emitter flow rate 4 L h⁻¹). The row spacing was set at 12 cm. In this study, rice cultivars named Firoozan, Jowzdan, an‎d Sazan‎degi were used at a seed rate of 80 kg ha⁻¹. To measure water consumption, each irrigation system was equipped separately with a water meter. On average, 40 irrigation operations were performed each year during the study period. The superabsorbent polymer used in this experiment was obtained from Bolur Ab Iran Company an‎d applied at 125 kg ha⁻¹ mixed with the top 20 cm of soil. To determine crop production relative to water consumption, the Irrigation Water Productivity Index (IWPI) was calculated. Additionally, yield an‎d its components were measured, including: plant height, tiller number, panicle length, Seed number per rice panicle (SNP), number of sterile seeds (NSS), 100-grain weight, grain yield, biological yield (BY), harvest index (HI), an‎d leaf area index (LAI). In this study, surface drip irrigation showed better results than subsurface irrigation, reducing water consumption by 20% compared to subsurface irrigation. Moreover, in the first year of the study, grain yield an‎d water productivity in the surface drip irrigation system were 19% an‎d 22% higher than in the subsurface system, respectively. These traits in the second year were approximately 15% an‎d 32% higher than the subsurface system, respectively. Grain yield in the superabsorbent treatment in the first an‎d second years was measured as 2549 an‎d 2695 kg ha⁻¹, respectively, while the grain yield in the treatment without superabsorbent was 2292 an‎d 2409 kg ha⁻¹ in the first an‎d second years, respectively. In other words, the use of superabsorbent in both years increased rice grain yield by 10%. Based on the results, among the tested cultivars in the studied region, the most suitable cultivar for direct seeded rice was Sazan‎degi, with an average grain yield of 3400 kg ha⁻¹.

جهانگير عابدي كوپائي , مهدي قيصري

حميدرضا عشقي زاده

محمد شايان نژاد , محمدرضا مصدقي , محمدرضا نوري امام زاده