We develop a continuous-time optimal control model for allocating agricultural crop residues between bioenergy production and soil fertility restoration. The system includes a circular reinvestment channel: a portion of the accumulated bioenergy stock is reinvested to enhance soil fertility, thereby closing the loop between energy use and ecological regeneration. The dynamics are governed by a three-state system with a single allocation control. The objective is to maximize a discounted net benefit that accounts for energy revenue, soil value, and operational costs. We apply the Pontryagin Maximum Principle in current-value form to derive necessary optimality conditions and a bang–interior–bang control; no singular arc under our parameterization. Direct optimization confirms a quasi-turnpike phase and shows how the planning horizon and reinvestment efficiency shift switching times and interior duration. The results highlight the strategic role of energy reinvestment in sustainable residue management.
[1] R. Alvarez, A quantitative review of the effects of residue removing on soil organic carbon in croplands, Soil Tillage Res. 240 (2024) 106098. [2] M.A.N. Anikwe, K. Ife, The role of soil ecosystem services in the circular bioeconomy, Front. Soil Sci. 3 (2023) 1209100. [3] J.M. Antle, S.M. Capalbo, E.T. Elliott, K.H.Paustian, Economic analysis of agricultural soil carbon sequestration: An integrated assessment approach, J. Agric. Resour. Econ. 26 (2001) 344–367. [4] S.M. Aseev, A.V. Kryazhimskii, The Pontryagin Maximum Principle and optimal economic growth problems, Proc. Steklov Inst. Math. 257 (2007) 1–255. [5] D. Beillouin, M. Corbeels, J. Demenois, D. Berre, A. Boyer, A. Fallot, F. Feder, R. Cardinael, A global meta-analysis of soil organic carbon in the world’s agricultural land, Nat. Commun. 14 (2023) 3630. [6] J.-B. Caillau, W. Djema, J.-L. Gouze, S. Maslovskaya, J.-B. Pomet, Turnpike property in optimal microbial metabolite production, J. Optim. Theory Appl. 194 (2022) 375–407. [7] J.-B. Caillau, R. Ferretti, E.Trelat, H. Zidani, An algorithmic guide for finite-dimensional optimal control problems, Handb. Numer. Anal. 24 (2023) 559–626. [8] O.C. Dekkaki, N.E. Khattabi, N. Raissi, Bioeconomic modeling of household waste recovery, Math. Methods Appl. Sci. 45 (2022) 468–482. [9] O. C. Dekkaki, W. Djema, Optimal control of a bioeconomic model applied to the recovery of household waste, Proc. Amer. Control Conf., San Diego (2023) 2135–2140. [10] O.C. Dekkaki, W. Djema, N. Raissi, N.E. Khattabi, Optimal control of waste recovery process, Int. J. Dyn. Control 12 (2024) 4244–4262. [11] O.C. Dekkaki, A. Bouhmady, I. Benamara, Multi-objective Optimal Control of a Bioenergy–Soil System under Fertility Constraints, Nonlinear Science 5 (2025) 100072. [12] C.W. Clark, Mathematical Bioeconomics: The Mathematics of Conservation, Third Edition, Wiley, Hoboken, 2010. [13] F.H. Clarke, Functional Analysis, Calculus of Variations and Optimal Control, Springer, London, 2013. [14] Clean energy for EU islands (European Commission), Feed-In Premium (Greece) reference prices for RES/CHP (biomass/biogas), Available at: https://clean-energy-islands.ec.europa.eu/ (accessed 8 Oct 2025). [15] M.S. Dhanoa, R. Sanderson, L.M. Cardenas, A. Shepherd, D.R. Chadwick, S. Lopez, J. France, Overview and application of the Mitscherlich equation and its extensions to estimate the soil nitrogen pool fraction associated with crop yield and nitrous oxide emission, Adv. Agron. 174 (2022) 269–295. [16] W. Djema, L. Giraldi, S. Maslovskaya, O. Bernard, Turnpike features in optimal selection of species represented by quota models, Automatica 132 (2021) 109804. [17] W. Djema, T. Bayen, O. Bernard, Optimal Darwinian selection of microorganisms with internal storage, Processes 10 (2022) 461. [18] European Securities and Markets Authority (ESMA), Carbon Markets Report 2024, Available at: https://www.esma.europa.eu/sites/default/files/2024-10/ESMA50-43599798-10379_Carbon_markets_report_2024.pdf (accessed 8 Oct 2025). [19] European Union, Council Regulation (EU) 2022/1854 emergency intervention to address high energy prices: market revenue cap at C180/MWh for inframarginal generators, EUR-Lex summary (2022), Available at: https://eur-lex.europa.eu/ (accessed 8 Oct 2025). [20] G. Flichman, Bio-Economic Models Applied to Agricultural Systems, Springer, Dordrecht, 2011. [21] B. Geshkovski, E. Zuazua, Turnpike in optimal control of PDEs, ResNets, and beyond, Acta Numer. 31 (2022) 135–263. [22] H.S. Gordon, The economic theory of a common-property resource: The fishery, J. Polit. Econ. 62 (1954) 124–142. [23] A. Haddon, H. Ramirez, A. Rapaport, Optimal and sub-optimal feedback controls for biogas production, J. Optim. Theory Appl. 183 (2019) 642–670. [24] M.I. Kamien, N. L. Schwartz, Dynamic Optimization: The Calculus of Variations and Optimal Control in Economics and Management, Dover, Mineola, 2012. [25] R. Lal, World crop residues production and implications of its use as a biofuel, Environ. Int. 31 (2005) 575–584. [26] J. Lehmann, S. Joseph, Biochar for Environmental Management: Science, Technology and Implementation (2nd ed.), Routledge, London/New York, 2015. [27] Y. Liu, M. Liu, Optimal control of crop irrigation with limited water resources, Math. Probl. Eng. 2016 (2016) 5076879. [28] L. Menichetti, G.I. Agren, P. Barre, F. Moyano, T. Katterer, Generic parameters of first-order kinetics accurately describe soil organic matter decay in bare fallow soils over a wide edaphic and climatic range, Sci. Rep. 9 (2019) 20319. [29] L.J.R. Nunes, Mathematical modeling approach to the optimization of biomass storage park management, Systems 12 (2024) 17. [30] R.D. Perlack, B.J. Stokes, U.S. Billion-Ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry, Oak Ridge Natl. Lab. 2011. [31] L.S. Pontryagin, Mathematical Theory of Optimal Processes, Springer, Berlin/Heidelberg, 1964. [32] Reuters, EU carbon market updates (2024–2025): price band roughly C60–C75/tCO2, News articles (accessed 8 Oct 2025). [33] M. Sandoval-Reyes, R. He, R. Semeano, P. Ferrao, Mathematical optimization of waste management systems: Methodological review and perspectives for application, Waste Manag. 174 (2024) 630–645. [34] M. Silva, M.B.P. Camargo, E.H. Schinor, Optimal control in pest management: a case study, Ecol. Model. 359 (2017) 132–140. [35] P. Smith, M. Bustamante, H. Ahammad, Agriculture, Forestry and Other Land Use (AFOLU), in: Climate Change 2014: Mitigation of Climate Change, Cambridge Univ. Press (2014). [36] E. Trelat, E. Zuazua, Turnpike in optimal control and beyond: a survey, arXiv preprint arXiv:2503.20342 (2025). [37] L. Tian, G. Shao, Y. Gao, E. Song, J. Lu, Effects of biochar on soil organic carbon in relation to soil nutrient contents, climate zones and cropping systems: A Chinese meta-analysis, Land 13 (2024) 1608. [38] G.C.V. Kooten, E.H. Bulte, The economics of nature: managing biological assets, Can. J. Agric. Econ. 42 (1994) 519–520. [39] R. Vinter, Optimal Control, Birkhauser, Boston, 2000. [40] X. Wang, C. He, B. Liu, X. Zhao, Y. Liu, Q. Wang, H. Zhang, Effects of residue returning on soil organic carbon: meta-analysis, Agronomy 10 (2020) 691. [41] C. Yirga, R. M. Hassan, Social costs and incentives for optimal control of soil nutrient depletion in the central highlands of Ethiopia, Agric. Syst. 103 (2010) 153–160.
Cherkaoui Dekkaki, O. (2026). Optimal control of a bioeconomic crop-energy system with energy reinvestment. Journal of Mathematical Modeling, 14(1), 327-346. doi: 10.22124/jmm.2025.31369.2815
MLA
Cherkaoui Dekkaki, O. . "Optimal control of a bioeconomic crop-energy system with energy reinvestment", Journal of Mathematical Modeling, 14, 1, 2026, 327-346. doi: 10.22124/jmm.2025.31369.2815
HARVARD
Cherkaoui Dekkaki, O. (2026). 'Optimal control of a bioeconomic crop-energy system with energy reinvestment', Journal of Mathematical Modeling, 14(1), pp. 327-346. doi: 10.22124/jmm.2025.31369.2815
CHICAGO
O. Cherkaoui Dekkaki, "Optimal control of a bioeconomic crop-energy system with energy reinvestment," Journal of Mathematical Modeling, 14 1 (2026): 327-346, doi: 10.22124/jmm.2025.31369.2815
VANCOUVER
Cherkaoui Dekkaki, O. Optimal control of a bioeconomic crop-energy system with energy reinvestment. Journal of Mathematical Modeling, 2026; 14(1): 327-346. doi: 10.22124/jmm.2025.31369.2815