نوع مقاله : مقاله پژوهشی
نویسندگان
1 موسسه اصلاح و تهیه نهال و بذر کرج، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران
2 دانشگاه رازی
3 موسسه تحقیقات اصلاح و تهیه نهال و بذر کرج، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract
Introduction: In Iran, wheat is more than just a crop; it is a strategic commodity with a high national security priority. Despite four decades of efforts toward self-sufficiency, the country's wheat production system continues to face structural challenges such as water stress, land fragmentation, and severe productivity fluctuations. A lack of comprehensive understanding regarding the transmission of climate-policy shocks and the short-term reciprocal interaction between cultivated area and yield has been the Achilles' heel of self-sufficiency programs. This study aims to fill this gap by investigating whether production growth drivers operate identically across the two farming systems (irrigated and rainfed) and determining the production outlook for the 2036 (1415 AH) horizon in light of ecological constraints.
Materials and Methods: Time series data for area, yield, and production spanning from 1982 to 2023 (42 years) served as the basis for analysis. The research methodology involved several analytical layers: 1) Univariate analyses including compound growth rates, stability assessment, and production growth decomposition; 2) Stationarity tests and determination of the order of integration; 3) Selection of optimal lag length and cointegration testing; 4) Specification of the dynamic model and diagnostic validity assessment; and finally, 5) Impulse Response Functions (IRF), Forecast Error Variance Decomposition (FEVD), and variable forecasting.
Findings: Analysis of the compound growth rate over the 42-year period indicates a paradigm shift in Iran's wheat production from horizontal expansion to vertical development strategies. Significant growth in total production (1.79%) and irrigated wheat (1.91%) was primarily driven by improvements in yield per unit area (growing at 1.72%). Diagnostic results revealed that structural shocks have transitory effects, and the system exhibits mean-reverting properties. FEVD analysis uncovered a fundamental divergence between the two systems: in the irrigated system, the cross-share of shocks was less than 0.2%, confirming structural independence and the dominant role of technology. Conversely, in the rainfed system, cultivated area shocks accounted for 20% of yield fluctuations, proving the phenomenon of ecological synchronicity (the simultaneous impact of rainfall on both area and yield). Forecasting results indicate that the total cultivated area will follow a fluctuating downward trend to reach 7.55 million hectares by 2036; however, total production will rise to 23.57 million tons, driven by a surge in irrigated yield (from 3892 kg/ha in the base year to 5104 kg/ha).
Conclusion: The findings of this research reject the area-centered development paradigm, particularly in rainfed regions. The future of wheat production security depends on vertical development and concentrating investment on yield enhancement in irrigated lands. Given the predicted contraction of rainfed area, the optimal strategy for this sector is not area expansion, but rather risk management and shifting cropping patterns toward resilient varieties.
کلیدواژهها [English]
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