MARKET CONCENTRATION AND NETWORK-BASED DEPENDENCY IN TÜRKIYE’S FERTILIZER IMPORTS: AN ANALYSIS OF NITROGEN, PHOSPHATE, AND POTASH TRADE

Abstract

This study empirically analyzes the evolution of supplier concentration and structural dependence in Türkiye’s imports of nitrogenous (HS 3102), phosphatic (HS 3103), and potassic (HS 3104) fertilizers from 2004 to 2023. Using annual bilateral trade data, the study applies a dual methodological framework that combines traditional scalar measures, including the Herfindahl-Hirschman Index (HHI), Entropy Index (EI), and concentration ratios (CR), with complex network analysis metrics to assess supply chain vulnerability. The findings reveal a clear structural divide across product groups. While the nitrogenous fertilizer market underwent a temporary phase of diversification between 2009 and 2016 before reconcentration, the phosphatic and potassic sectors maintained persistently high oligopolistic concentration levels throughout the study period. Network analysis corroborates these scalar indicators, identifying Türkiye as a peripheral, demand-side actor characterized by marked single-sourcing risks in phosphate and potash trade, in contrast to its relatively well-connected importer position linked to core suppliers in the nitrogen network. The study concludes that the high level of import concentration observed in these critical inputs creates significant supply security risks by exposing agricultural input markets to geopolitical and economic shocks. These results underscore the need for policy measures that prioritize supplier diversification and integrate resilience criteria into national food security strategies.

Keywords

• Fertilizer
• Market Concentration
• Herfindahl–Hirschman Index
• Entropy Index
• Network Analysis

Ethical Statement

I declare that the study does not require ethics committee permission.

TÜRKİYE’NİN GÜBRE İTHALATINDA PAZAR YOĞUNLAŞMASI VE AĞ TABANLI BAĞIMLILIK: AZOT, FOSFAT VE POTAS TİCARETİ ANALİZİ

Abstract

Bu çalışma, Türkiye’nin azotlu (HS 3102), fosfatlı (HS 3103) ve potasyumlu (HS 3104) gübre ithalatında tedarikçi yoğunlaşması ve yapısal bağımlılığın 2004–2023 dönemindeki gelişimini ampirik olarak analiz etmektedir. Yıllık ikili ticaret verilerinden yararlanılan çalışmada, tedarik zinciri kırılganlığını değerlendirmek amacıyla Herfindahl–Hirschman Endeksi (HHI), Entropi Endeksi (EI) ve yoğunlaşma oranları (CR) gibi geleneksel ölçütler ile kompleks ağ analizi metriklerini bir araya getiren ikili bir yöntemsel çerçeve kullanılmıştır. Bulgular, ürün grupları arasında belirgin bir yapısal farklılaşma olduğunu ortaya koymaktadır. Azotlu gübre piyasasında 2009–2016 döneminde geçici bir çeşitlenme süreci yaşanmış, ancak sonrasında yeniden yoğunlaşma eğilimi görülmüştür. Buna karşılık fosfatlı ve potasyumlu gübrelerde çalışma dönemi boyunca sürekli yüksek ve oligopolistik yoğunlaşma düzeyleri gözlenmiştir. Ağ analizi bulguları da bu yoğunlaşma göstergelerini desteklemekte; Türkiye’nin fosfat ve potasyum ticaretinde belirgin tek tedarikçiye bağımlılık riski taşıyan çevresel ve talep yönlü bir aktör olduğunu, azotlu gübre ağında ise çekirdek tedarikçilerle bağlantılı görece daha iyi bağlantılanmış bir ithalatçı konumunda bulunduğunu göstermektedir. Çalışma, söz konusu kritik girdilerde gözlenen yüksek ithalat yoğunlaşmasının, tarımsal girdi piyasalarını jeopolitik ve ekonomik şoklara açık hâle getirerek önemli arz güvenliği riskleri oluşturduğu sonucuna ulaşmaktadır. Bu bulgular, tedarikçi çeşitlendirmesini önceleyen ve dayanıklılık kriterlerini ulusal gıda güvenliği stratejilerine entegre eden politika önlemlerine ihtiyaç duyulduğunu göstermektedir.

Keywords

• Gübre
• Pazar Yoğunlaşması
• Herfindahl–Hirschman Endeksi
• Entropi Endeksi
• Ağ Analizi

Ethical Statement

Bu çalışmanın etik kurul onayına gerek duymadığını beyan ederim.

References

1. AbdulKafi, A. R. (2024). Supply chain issues in times of pandemics and crises: A study on the COVID-19 and Ukraine crises. Qlantic Journal of Social Sciences, 5(3), 353–361. https://doi.org/10.55737/qjss.v-iii.24375
2. Akmermer, B. (2022). Güncel gelişmelerin etkisinde gübre sektörü küresel ticareti ve Türkiye’nin tarımsal sürdürülebilirliğine etkileri. V. Uluslararası Kahramanmaraş Yönetim, Ekonomi ve Siyaset Kongresi bildiri kitabı içinde (ss. 135–148).
3. Anthem, P. (2025). Food security – what it means and why it matters. World Food Programme. Retrieved November 15, 2025, from https://www.wfp.org/stories/food-security-what-it-means-and-why-it-matters
4. Bain, J. S. (1951). Relation of profit rate to industry concentration: American manufacturing, 1936–1940. The Quarterly Journal of Economics, 65(3), 293–324.
5. Barrat, A., Barthélemy, M., Pastor-Satorras, R., & Vespignani, A. (2004). The architecture of complex weighted networks. Proceedings of the National Academy of Sciences, 101(11), 3747–3752.
6. Bilge, B., & Artukoğlu, M. (2019). Türkiye’de son yıllarda gübrede uygulanan politikalara genel bir bakış. Tarım Ekonomisi Dergisi, 25(2), 275–281. https://doi.org/10.24181/tarekoder.629455
7. Bonacich, P. (1972). Factoring and weighting approaches to status scores and clique identification. Journal of Mathematical Sociology, 2(1), 113–120.
8. Bor, O., & Dağıstan, N. (2024). The impact of fluctuating international fertiliser prices and exchange rates on domestic fertiliser prices in Türkiye. Agricultural Economics – Czech, 70(7), 308–318. https://doi.org/10.17221/308/2023-AGRICECON

9. Brownlie, W. J., Sutton, M. A., Cordell, D., Reay, D. S., Heal, K. V., Withers, P. J., ... & Spears, B. M. (2023). Phosphorus price spikes: A wake-up call for phosphorus resilience. Frontiers in Sustainable Food Systems, 7, 1088776. https://doi.org/10.3389/fsufs.2023.1088776
10. Dawson, C. J., & Hilton, J. (2011). Fertiliser availability in a resource-limited world: Production and recycling of nitrogen and phosphorus. Food Policy, 36, S14–S22. https://doi.org/10.1016/j.foodpol.2010.11.012
11. Döös, B. R. (2002). Population growth and loss of arable land. Global Environmental Change, 12(4), 303–311. https://doi.org/10.1016/S0959-3780(02)00043-2
12. Eraslan, F., İnal, A., Güneş, A., Erdal, İ., & Coşkan, A. (2010). Türkiye’de kimyasal gübre üretim ve tüketim durumu, sorunlar, çözüm önerileri ve yenilikler. Ziraat Mühendisliği VII. Teknik Kongresi bildirileri içinde (ss. 1–21). TMMOB Ziraat Mühendisleri Odası.
13. Fagiolo, G., Reyes, J., & Schiavo, S. (2009). World-trade web: Topological properties, dynamics, and evolution. Physical Review E, 79(3), 036115.
14. FAO. (2006). Food security (Policy brief, Issue 2). Retrieved November 20, 2025, from https://www.fao.org/fileadmin/templates/faoitaly/documents/pdf/pdf_Food_Security_Cocept_Note.pdf
15. Freeman, L. C. (1977). A set of measures of centrality based on betweenness. Sociometry, 40(1), 35–41.
16. Fruchterman, T. M., & Reingold, E. M. (1991). Graph drawing by force-directed placement. Software: Practice and Experience, 21(11), 1129–1164.
17. Geissler, B., Mew, M. C., & Steiner, G. (2019). Phosphate supply security for importing countries: Developments and the current situation. Science of the Total Environment, 677, 511–523. https://doi.org/10.1016/j.scitotenv.2019.04.356
18. Güler, S. (2006). Developments on fertilizer consumption of the world and Turkey. Anadolu Tarım Bilimleri Dergisi, 21(2), 243–248.
19. Gutiérrez-Moya, E., Lozano, S., & Adenso-Díaz, B. (2023). A pre-pandemic analysis of the global fertiliser trade network. Resources Policy, 85, 103859. https://doi.org/10.1016/j.resourpol.2023.103859
20. Herfindahl, O. C. (1950). Concentration in the steel industry (Doctoral dissertation). Columbia University.
21. Hernandez, M. A., & Torero, M. (2013). Market concentration and pricing behavior in the fertilizer industry: A global approach. Agricultural Economics, 44(6), 723–734. https://doi.org/10.1111/agec.12084
22. Hirschman, A. O. (1945). National power and the structure of foreign trade. University of California Press.
23. Jones, D., & Deuss, A. (2024). Understanding the resilience of fertiliser markets to shocks: An overview of fertiliser policies (OECD Food, Agriculture and Fisheries Papers, No. 208). OECD Publishing.
24. Li, M. Y., Wang, L., Xie, W. J., & Zhou, W. X. (2022). Quantifying the temporal stability of international fertilizer trade networks. Journal of Complex Networks, 11(5). https://doi.org/10.1093/comnet/cnad037
25. Muminjanov, H., & Karagöz, A. (2018). Biodiversity of Turkey: Contribution of genetic resources to sustainable agriculture and food systems. FAO. Retrieved November 25, 2025, from https://openknowledge.fao.org/handle/20.500.14283/ca1517en
26. Murphy, S. (2006). Concentrated market power and agricultural trade (Ecofair Trade Dialogue Discussion Papers, No. 1). Retrieved December 19, 2025, from https://www.iatp.org/sites/default/files/451_2_89014.pdf
27. Newman, M. E. J. (2010). Networks: An introduction. Oxford University Press.
28. Nie, F., Li, J., Bi, X., & Li, G. (2022). Agricultural trade liberalization and domestic fertilizer use: Evidence from China-ASEAN free trade agreement. Ecological Economics, 195, 107341. https://doi.org/10.1016/j.ecolecon.2022.107341
29. Raddant, M., Bertau, M., & Steiner, G. (2025). Advancing the analysis of resilience of global phosphate flows. Resources, 14(10), 151. https://doi.org/10.3390/resources14100151
30. Saccone, D., & Vallino, E. (2025). Global food security in a turbulent world: Reviewing the impacts of the pandemic, the war and climate change. Agricultural and Food Economics, 13(1), 47. https://doi.org/10.1186/s40100-025-00388-0
31. Sarwar, D., & Rye, S. (2025). The impact of the Russia-Ukraine war on global supply chains: A systematic literature review. Frontiers in Sustainable Food Systems, 9, 1648918. https://doi.org/10.3389/fsufs.2025.1648918
32. Scherer, F. M., & Ross, D. (1990). Industrial market structure and economic performance (3rd ed.). Houghton Mifflin.
33. Schwellnus, C., Haramboure, A., & Samek, L. (2023). Policies to strengthen the resilience of global value chains: Empirical evidence from the COVID-19 shock (OECD Science, Technology and Industry Policy Papers No. 1412). OECD. Retrieved November 14, 2025, from https://www.oecd.org/content/dam/oecd/en/publications/reports/2023/02/policies-to-strengthen-the-resilience-of-global-value-chains_e6dcc19a/fd82abd4-en.pdf
34. Şeyranlıoğlu, O., & Keskin, Ö. (2025). Does foreign trade in agricultural raw materials promote agricultural credit in Türkiye? Fourier-based evidence on import-and export-led growth hypotheses. Turkish Journal of Agricultural and Natural Sciences, 12(4), 1041–1055. https://doi.org/10.30910/turkjans.1671360
35. Shannon, C. E. (1948). A mathematical theory of communication. The Bell System Technical Journal, 27(3), 379–423.
36. Sharma, S. K., Routroy, S., Singh, R. K., & Nag, U. (2024). Analysis of supply chain vulnerability factors in manufacturing enterprises: A fuzzy DEMATEL approach. International Journal of Logistics Research and Applications, 27(5), 814–841. https://doi.org/10.1080/13675567.2022.2083590
37. Singh, A. K., Pathak, M., Joshi, M. D., Kumar, S., Kashyap, S., & Hasan, W. (2024). The role of agriculture in poverty alleviation and rural development. Journal of Scientific Research and Reports, 30(8), 529–549. https://doi.org/10.9734/jsrr/2024/v30i82276
38. Taheri Hosseinkhani, N. (2025). Global food security amid geopolitical tensions and climate risk: Trade governance and adaptive strategies. SSRN. https://doi.org/10.2139/ssrn.5448314
39. Theil, H. (1967). Economics and information theory. North-Holland.
40. Tıraş, H. H. (2024). Tarım üretiminde önde gelen ülkelerde tarımsal gübre ve ilaç kullanımının tarımsal GSYİH’ye etkisi; panel veri analizi araştırması. Business & Management Studies: An International Journal, 12(1), 132–147. https://doi.org/10.15295/bmij.v12i1.2352
41. UN Comtrade. (2025). UN Comtrade database. Retrieved November 01, 2025, from https://comtradeplus.un.org/TradeFlow
42. Yin, W., & Ran, W. (2022). Supply chain diversification, digital transformation, and supply chain resilience: Configuration analysis based on FSQCA. Sustainability, 14(13), 7690. https://doi.org/10.3390/su14137690