Document Type : Original Article
Authors
- Ali Abedinzadeh 1
- Ahmad Ghanbari 2
- Mohammad Reza Asgharipour 2
- Alireza Sirousmehr 3
- Ahmad Ahmadian 4
1 Ph.D. Student of Agrotechnology, Department of Agronomy, University of Zabol, Iran.
2 Professor, Department of Agronomy, University of Zabol, Iran.
3 Associate Professor, Department of Agronomy, University of Zabol, Iran.
4 Assistant Professor, Department of Agronomy, University of Torbat Heydarieh, Torbat Heydarieh, Iran.
Abstract
Introduction: Saffron (Crocus sativus L.), recognized as the world’s most expensive agricultural and medicinal crop, holds a pivotal role in Iran’s agricultural economy, particularly in arid and semi-arid regions such as Torbat Heydarieh and Zaveh. After saffron harvest, the fields are typically utilized for subsequent crops like cumin (Cuminum cyminum L.) and sesame (Sesamum indicum L.), offering opportunities for crop diversification and income enhancement. This study addresses the economic challenges faced by farmers in saffron-producing regions of Iran, where soil fertility decline and water scarcity necessitate sustainable crop rotation strategies. Cumin, a drought-tolerant medicinal plant with significant export value, and sesame, a resilient oilseed crop, are promising candidates for post-saffron cultivation. The research aims to compare the quantitative and qualitative performance of these crops under varying land-use histories (saffron fields vs. fallow lands), providing insights into optimizing agricultural management and boosting farmers’ livelihoods. Understanding the influence of saffron residues, potential allelopathic effects, and soil conditions on subsequent crops is critical for developing effective farming practices in these regions.
Materials and Methods: The experiment was conducted during the 2022-2023 growing season in Torbat Heydarieh and Zaveh, two key saffron-producing areas in Khorasan Razavi Province, Iran. A split-plot design within a randomized complete block arrangement with three replications was employed. Main plots consisted of two prior land-use types: fields with a 5-year fallow period and fields previously cultivated with saffron (corms removed post-harvest). Subplots included two plant species: cumin and sesame. Cumin was sown at 18 kg/ha and sesame at 6 kg/ha, with seeds sourced from the Khorasan Razavi Agricultural Jihad Organization. Fertilization involved urea (400 g/plot), triple superphosphate (300 g/plot), and potassium sulfate (300 g/plot), applied in stages tailored to each crop’s growth phases. Plots measured 10 m², with 1 m spacing between subplots and 2 m between main plots. Evaluated traits included soil physical and chemical properties (e.g., pH, EC, N, P, K) before and after cultivation, yield components (e.g., seed yield, biological yield), plant growth parameters (e.g., height, seed number), and economic performance. Soil samples were analyzed for texture, organic carbon, and nutrient content. Data were statistically analyzed using SAS (version 12), with means compared via Duncan’s multiple range test at a 5% significance level.
Results and Discussion: Results revealed that fields previously cultivated with saffron significantly outperformed 5-year fallow lands in terms of seed yield, biological yield, and economic returns for both cumin and sesame. In saffron fields, cumin exhibited a 15.75% increase in seed yield and an 18.71% rise in biological yield compared to fallow fields, while sesame showed a 33.26% and 23.87% increase, respectively. These improvements are likely due to enhanced soil organic matter from saffron corm residues, despite potential allelopathic effects reported in prior studies. Zaveh outperformed Torbat Heydarieh across most traits, with cumin seed yield 27.25% higher and sesame 24.94% higher, possibly due to Zaveh’s more favorable soil conditions (lower salinity, moderate alkalinity). Sesame displayed a higher harvest index (20.72% in saffron fields) than cumin (36.79%), indicating greater efficiency in converting biomass to seed. However, cumin’s economic yield was nearly three times that of sesame (93.26 million IRR vs. 32.57 million IRR), driven by higher market value and yield stability. Soil analysis showed no significant post-cultivation changes, suggesting sustained fertility in saffron fields. These findings underscore the economic superiority of cumin and the positive legacy effects of saffron cultivation on subsequent crops.
Conclusion: This study demonstrates that cultivating cumin and sesame after saffron harvest is a viable strategy for enhancing farmer income and agricultural sustainability in Iran’s saffron regions. Cumin emerges as the more economically advantageous option due to its higher yield, income potential, and adaptability to local conditions, making it the recommended choice for post-saffron cultivation. Sesame, while less profitable, offers resilience and a higher harvest index, serving as a complementary crop in rotation systems. Saffron fields provide a superior starting point compared to fallow lands, highlighting the benefits of saffron residues for soil health. These results offer practical guidance for farmers and a foundation for future research into optimizing crop rotations in arid environments.
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