Effects of biogas-derived liquid digestates on wheat yield, kernel quality and economic performance under semi-arid conditions

Gamze Depel; Zeynep Demir; Derya Özalp Ünal; Ayten Namlı; Nihal Ceren Alıcı; Özgür Doğan

doi:10.18393/ejss.1962099

Effects of biogas-derived liquid digestates on wheat yield, kernel quality and economic performance under semi-arid conditions

Abstract

This study evaluated the effects of biogas-derived liquid digestates on wheat yield, yield components, kernel quality, nutrient contents, and economic performance under semi-arid Central Anatolian conditions. Field experiments were conducted using three digestate types—poultry manure + poppy residue (PP), cattle manure + plant waste (CP), and a poultry + cattle mixture (PC)—applied at 15, 30, 45, and 60 t ha⁻¹, alongside control and NPK treatments. Liquid digestates significantly increased kernel yield compared with the control, with clear differences among digestate types and application rates. Under PP, CP, and PC treatments, yield increased from 2195.2 to 2717.9 kg ha⁻¹, from 2352.2 to 2850.9 kg ha⁻¹, and from 2393.7 to 2807.0 kg ha⁻¹, respectively, with maximum values observed at 30 t ha⁻¹. NPK consistently produced high yields (2807.9-2977.1 kg ha⁻¹). Yield components improved under digestate applications. Digestate applications improved several yield-related traits across all digestate types. Harvest index, plant height, spike length, peduncle length, stem + spikelet weight, spikelet kernel number, spikelet kernel weight, and thousand kernel weight generally increased under digestate treatments compared with the control, although the magnitude of response varied according to digestate source and application rate. Kernel quality traits varied moderately, with crude protein (12.94-16.01%), wet gluten (24.73-36.0%), and Zeleny sedimentation (39.0-62.0 mL). Under PP digestate application, K and Ca levels in wheat kernels were significant (p < 0.01), whereas CP and PC showed limited effects, with significance observed only for Fe. Multivariate analyses indicated that net income was primarily driven by kernel yield and its components. Economic evaluation showed that digestate applications increased profitability, with the highest net income under CP at 30 t ha⁻¹ ($955.2 ha⁻¹ yr⁻¹). Although the highest yield and net income were generally obtained around 30 t ha⁻¹, 15 t ha⁻¹ may represent a safer option where salinity risk and long-term soil effects are major concerns. Overall, biogas liquid digestates—especially CP and PC applied at moderate rates—represent effective and economically viable nutrient sources for wheat production in semi-arid systems. However, further multi-year studies are required to assess long-term impacts on soil properties, nutrient dynamics, and environmental sustainability.

Keywords

Supporting Institution

Republic of Türkiye Ministry of Agriculture and Forestry, General Directorate of Agricultural Research and Policies (TAGEM)

Project Number

TAGEM/TSKAD/G/21/A9/P1/5549

Thanks

The authors would like to thank the Republic of Türkiye Ministry of Agriculture and Forestry, General Directorate of Agricultural Research and Policies (TAGEM), for the financial support provided for the project TAGEM/TSKAD/G/21/A9/P1/5549. The authors also thank the editors and anonymous reviewers for their helpful comments, corrections, and suggestions on the previous version of the manuscript.

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Details

Primary Language

English

Subjects

Soil Sciences and Plant Nutrition (Other)

Journal Section

Research Article

Authors

Gamze Depel
0000-0003-2749-8243
Türkiye

Zeynep Demir ^*
0000-0002-7589-3216
Türkiye

Derya Özalp Ünal
0000-0002-0268-9812
Türkiye

Ayten Namlı
0000-0003-1913-2751
Türkiye

Nihal Ceren Alıcı
0000-0002-2147-0760
Türkiye

Özgür Doğan
0000-0002-7415-5369
Türkiye

Publication Date

June 30, 2026

Submission Date

January 13, 2026

Acceptance Date

May 20, 2026

Published in Issue

Year 2026 Volume: 15 Number: 3

DOI

https://doi.org/10.18393/ejss.1962099

IZ

https://izlik.org/JA92JW39ED

Cite

RIS / Bibtex

APA

Depel, G., Demir, Z., Özalp Ünal, D., Namlı, A., Alıcı, N. C., & Doğan, Ö. (2026). Effects of biogas-derived liquid digestates on wheat yield, kernel quality and economic performance under semi-arid conditions. Eurasian Journal of Soil Science, 15(3), 428-443. https://doi.org/10.18393/ejss.1962099

AMA

1.Depel G, Demir Z, Özalp Ünal D, Namlı A, Alıcı NC, Doğan Ö. Effects of biogas-derived liquid digestates on wheat yield, kernel quality and economic performance under semi-arid conditions. EJSS. 2026;15(3):428-443. doi:10.18393/ejss.1962099

Chicago

Depel, Gamze, Zeynep Demir, Derya Özalp Ünal, Ayten Namlı, Nihal Ceren Alıcı, and Özgür Doğan. 2026. “Effects of Biogas-Derived Liquid Digestates on Wheat Yield, Kernel Quality and Economic Performance under Semi-Arid Conditions”. Eurasian Journal of Soil Science 15 (3): 428-43. https://doi.org/10.18393/ejss.1962099.

EndNote

Depel G, Demir Z, Özalp Ünal D, Namlı A, Alıcı NC, Doğan Ö (June 1, 2026) Effects of biogas-derived liquid digestates on wheat yield, kernel quality and economic performance under semi-arid conditions. Eurasian Journal of Soil Science 15 3 428–443.

IEEE

[1]G. Depel, Z. Demir, D. Özalp Ünal, A. Namlı, N. C. Alıcı, and Ö. Doğan, “Effects of biogas-derived liquid digestates on wheat yield, kernel quality and economic performance under semi-arid conditions”, EJSS, vol. 15, no. 3, pp. 428–443, June 2026, doi: 10.18393/ejss.1962099.

ISNAD

Depel, Gamze - Demir, Zeynep - Özalp Ünal, Derya - Namlı, Ayten - Alıcı, Nihal Ceren - Doğan, Özgür. “Effects of Biogas-Derived Liquid Digestates on Wheat Yield, Kernel Quality and Economic Performance under Semi-Arid Conditions”. Eurasian Journal of Soil Science 15/3 (June 1, 2026): 428-443. https://doi.org/10.18393/ejss.1962099.

JAMA

1.Depel G, Demir Z, Özalp Ünal D, Namlı A, Alıcı NC, Doğan Ö. Effects of biogas-derived liquid digestates on wheat yield, kernel quality and economic performance under semi-arid conditions. EJSS. 2026;15:428–443.

MLA

Depel, Gamze, et al. “Effects of Biogas-Derived Liquid Digestates on Wheat Yield, Kernel Quality and Economic Performance under Semi-Arid Conditions”. Eurasian Journal of Soil Science, vol. 15, no. 3, June 2026, pp. 428-43, doi:10.18393/ejss.1962099.

Vancouver

1.Gamze Depel, Zeynep Demir, Derya Özalp Ünal, Ayten Namlı, Nihal Ceren Alıcı, Özgür Doğan. Effects of biogas-derived liquid digestates on wheat yield, kernel quality and economic performance under semi-arid conditions. EJSS. 2026 Jun. 1;15(3):428-43. doi:10.18393/ejss.1962099