Biochar application regulating soil inorganic nitrogen and organic carbon content in cropland in the Central Europe: a seven-year field study

Abstract

Biochar incorporation into soil has shown potential, in enhancing nitrogen fertilizer (N-fertilizer) efficacy and soil organic carbon content (SOC). This study addresses a critical gap in the literature by investigating the effects of biochar addition over a seven-year period (2014–2020) on inorganic N, SOC, and pH in Haplic Luvisol. The research involved a rain-fed field experiment, with a crop rotation comprising spring barley, maize, spring wheat, and pea. Biochar, applied at the rates of 0, 10, and 20 t ha⁻¹ in 2014, was reapplied to specific plots in 2018. Biochar was also combined with N-fertilizer at three level (N0, N1, and N2). Results showed a significant interactive influence of biochar and N-fertilizer combination on NO₃ ⁻ and NH₄ ⁺ contents. Intriguingly, the addition of 10 t biochar ha⁻¹ consistently decreased soil inorganic N levels across most of the examined months. Increasing biochar application rates led to a significant rise in pH, establishing a clear, negative correlation between soil pH and inorganic N content. Biochar significantly increased SOC compared to the control, particularly after the reapplication in 2018. However, this effect showed a diminishing trend over time. The study suggests that incorporating biochar treatments may enhance N-fertilizer effectiveness. However, the long-term implications of biochar application with N-fertilizer on N mineralization are specific to individual soil and biochar combinations. Except the application of 20 t ha⁻¹ biochar at N2 in 2019, biochar did not affect the crop yields. Studied soil properties, including those influenced by biochar had nuanced impact on different aspects of crop yield.

Article Highlights

•	Biochar obtained from mixed paper fiber sludge and the grain husks resulted in a significant increase of SOC over 7 years.
•	Biochar aging resulted in a decrease in pH one year after its application in 2015 and 2019.
•	The combination of N-fertilizer with biochar caused an improvement in soil inorganic N content in 2014 and reapplication in 2018.

Keywords

Field experiment / Biochar / Inorganic nitrogen / Soil organic carbon / Soil pH

References

[1] Agegnehu G, Nelson PN, Bird MI. The effects of biochar, compost and their mixture and nitrogen fertilizer on yield and nitrogen use efficiency of barley grown on a Nitisol in the highlands of Ethiopia. Sci Total Environ, 2016, 569: 869-879,

[2] Ali I, Ullah S, He L, Zhao Q, Iqbal A, Wei S, Shah T, Ali N, Bo Y, Adnan M, Jiang L. Combined application of biochar and nitrogen fertilizer improves rice yield, microbial activity and N-metabolism in a pot experiment. Peer J, 2020, 8: 10311,

[3] Arif MS, Riaz M, Shahzad SM, Yasmeen T, Ashraf M, Siddique M, Mubarik MS, Bragazza L, Buttler A. Fresh and composted industrial sludge restore soil functions in surface soil of degraded agricultural land. Sci Total Environ, 2018, 619–620: 517-527,

[4] Aydin E. Vplyv dlhodobého účinku aplikácie biouhlia a krátkodobého účinku jeho opakovanej aplikácie v kombinácii s hnojením na úrody vybraných plodín [Impact of long-term effect of biochar application and short-term effect of its repeated application in combination with fertilization on yields of selected crops]. Habilitation thesis. SPU v Nitre, Nitra, Slovakia, 2021.

[5] Aydin E, Horák J, Igaz D, Šimanský V. Changes in crop yields as a result of biochar application and reapplication. Proceedings of the international scientific seminar. Biochar: properties, application in agriculture, effect on soils, crops and environment. Agrophysical Research Institute, St. Petersburg, Russia, December 08, 2020a.

[6] Aydin E, Šimanský V, Horák J, Igaz D. Potential of biochar to alternate soil properties and crop yields 3 and 4 years after the application. Agronomy, 2020, 10: 889,

[7] Badu E, Kaba JS, Abunyewa AA, Dawoe EK, Agbenyega O, Barnes RV. Biochar and inorganic nitrogen fertilizer effects on maize (Zea mays L.) nitrogen use and yield in moist semi-deciduous forest zone of Ghana. J Plant Nutr, 2019, 42(19): 2407-2422,

[8] Bai SH, Omidvar N, Gallart M, Kämper W, Tahmasbian I, Farrar MB, Singh K, Zhou G, Muqadass B, Xu CY, Koech R. Combined effects of biochar and fertilizer applications on yield: a review and meta-analysis. Sci Total Environ, 2022, 808,

[9] Berihun T, Tolosa S, Tadele M, Kebede F. Effect of biochar application on growth of garden pea (Pisum sativum L.) in acidic soils of Bule Woreda Gedeo Zone Southern Ethiopia. Int J Agron., 2017, 2017: 1-8,

[10] Bista P, Ghimire R, Machado S, Pritchett L. Biochar effects on soil properties and wheat biomass vary with fertility management. Agronomy, 2019, 9(10): 623,

[11] Blanco-Canqui H. Does biochar improve all soil ecosystem services?. GCB Bioenergy, 2021, 13(4): 291-304,

[12] Borchard N, Schirrmann M, Cayuela ML, Kammann C, Wrage-Mönnig N, Estavillo JM, Fuertes-Mendizábal T, Sigua G, Spokas K, Ippolito JA, Novak J. Biochar, soil and land-use interactions that reduce nitrate leaching and N₂O emissions: a meta-analysis. Sci Total Environ, 2019, 651: 2354-2364,

[13] Cameron KC, Di HJ, Moir JL. Nitrogen losses from the soil/plant system: a review. Ann Appl Biol, 2013, 162: 145-173,

[14] Cayuela ML, Van Zwieten L, Singh BP, Jeffery S, Roig A, Sánchez-Monedero MA. Biochar's role in mitigating soil nitrous oxide emissions: a review and meta-analysis. Agric Ecosyst Environ, 2014, 191: 5-16,

[15] Dai Z, Zhang X, Tang C, Muhammad N, Wu J, Brookes PC, Xu J. Potential role of biochars in decreasing soil acidification-a critical review. Sci Total Environ, 2017, 581: 601-611,

[16] DeLuca TH, Gundale MJ, MacKenzie MD, Jones DL. Biochar effects on soil nutrient transformations. In Biochar for Environmental Management (pp. 453–486). Routledge; 2015.

[17] Dong W, Zhang X, Wang H, Dai X, Sun X, Qiu W, Yang F. Effect of different fertilizer application on the soil fertility of paddy soils in red soil region of southern China. PLoS ONE, 2012, 7(9),

[18] Dong L, Yang X, Shi L, Shen Y, Wang L, Wang J, Li C, Zhang H. Biochar and nitrogen fertilizer co-application changed SOC content and fraction composition in Huang-Huai-Hai plain. China Chemosphere, 2022, 291,

[19] Dziadowiec H, Gonet SS. . A guide to the methods for determination of soil organic matter, 1999 Warszawa Pr Kom Nauk PTG 65

[20] Elnour AY, Alghyamah AA, Shaikh HM, Poulose AM, Al-Zahrani SM, Anis A, Al-Wabel MI. Effect of pyrolysis temperature on biochar microstructural evolution, physicochemical characteristics, and its influence on biochar/polypropylene composites. Appl Sci, 2019, 9(6): 1149,

[21] Frimpong KA, Phares CA, Boateng I, Abban-Baidoo E, Apuri L. One-time application of biochar influenced crop yield across three cropping cycles on tropical sandy loam soil in Ghana. Heliyon, 2021, 7(11),

[22] Fuertes-Mendizábal T, Huérfano X, Vega-Mas I, Torralbo F, Menéndez S, Ippolito JA, Kammann C, Wrage-Mönnig N, Cayuela ML, Borchard N, Spokas K. Biochar reduces the efficiency of nitrification inhibitor 3, 4-dimethylpyrazole phosphate (DMPP) mitigating N₂O emissions. Sci Rep, 2019, 9(1): 2346,

[23] Geng N, Kang X, Yan X, Yin N, Wang H, Pan H, Yang Q, Lou Y, Zhuge Y. Biochar mitigation of soil acidification and carbon sequestration is influenced by materials and temperature. Ecotoxicol Environ Saf, 2022, 232,

[24] Hagemann N, Harter J, Kaldamukova R, Guzman-Bustamante I, Ruser R, Graeff S, Kappler A, Behrens S. Does soil aging affect the N₂O mitigation potential of biochar? A combined microcosm and field study. Gcb Bioenergy, 2017, 9(5): 953-964,

[25] Hardy B, Sleutel S, Dufey JE, Cornelis JT. The long-term effect of biochar on soil microbial abundance, activity and community structure is overwritten by land management. Front Environ Sci, 2019, 7: 110,

[26] Hernandez-Soriano MC, Kerré B, Goos P, Hardy B, Dufey J, Smolders E. Long-term effect of biochar on the stabilization of recent carbon: soils with historical inputs of charcoal. Gcb Bioenergy, 2016, 8(2): 371-381,

[27] Horák J, Šimanský V. Effect of biochar and biochar combined with N-fertiliser on soil organic carbon content. Agriculture/pol'nohospodárstvo., 2016, 62(4): 155,

[28] Horák J, Šimanský V, Aydin E. Benefits of biochar and its combination with nitrogen fertilization for soil quality and grain yields of barley, wheat and corn. J Elementol, 2020, 25(2): 443-458,

[29] Hossain MZ, Bahar MM, Sarkar B, Donne SW, Ok YS, Palansooriya KN, Kirkham MB, Chowdhury S, Bolan N. Biochar and its importance on nutrient dynamics in soil and plant. Biochar, 2020, 2: 379-420,

[30] Igaz D, Šimanský V, Horák J, Kondrlová E, Domanová J, Rodný M, Buchkina NP. Can a single dose of biochar affect selected soil physical and chemical characteristics?. J Hydrol Hydromech, 2018, 66: 421-428,

[31] Ippolito JA, Novak JM, Busscher WJ, Ahmedna M, Rehrah D, Watts DW. Switchgrass biochar affects two Aridisols. J Environ Qual, 2012, 41: 1123-1130,

[32] Jeffery S, Abalos D, Prodana M, Bastos AC, Van Groenigen JW, Hungate BA, Verheijen F. Biochar boosts tropical but not temperate crop yields. Environ Res Lett, 2017, 12,

[33] Juriga M, Šimanský V. Effects of biochar and its reapplication on soil pH and sorption properties of silt loam haplic Luvisol. Acta Horticulturae Et Regiotecturae, 2019, 22: 65-70,

[34] Kalu S, Simojoki A, Karhu K, Tammeorg P. Long-term effects of softwood biochar on soil physical properties, greenhouse gas emissions and crop nutrient uptake in two contrasting boreal soils. Agric Ecosyst Environ, 2021, 316,

[35] Karer J, Wimmer B, Zehetner F, Kloss S, Soja G. Biochar application to temperate soils: effects on nutrient uptake and crop yield under field conditions. Agric Food Sci, 2013, 22(4): 390-403,

[36] Kemmitt SJ, Wright D, Goulding KW, Jones DL. pH regulation of carbon and nitrogen dynamics in two agricultural soils. Soil Biol Biochem, 2006, 38(5): 898-911,

[37] Khan Z, Zhang K, Khan MN, Bi J, Zhu K, Luo L, Hu L. How biochar affects nitrogen assimilation and dynamics by interacting soil and plant enzymatic activities: quantitative assessment of 2 years potted study in a rapeseed-soil system. Front Plant Sci, 2022, 13: 853449-853449,

[38] Khan Z, Yang XJ, Fu Y, Joseph S, Khan MN, Khan MA, Alam I, Shen H. Engineered biochar improves nitrogen use efficiency via stabilizing soil water-stable macroaggregates and enhancing nitrogen transformation. Biochar, 2023, 5(1): 52,

[39] Lal R. Soil carbon sequestration to mitigate climate change. Geoderma, 2004, 123: 1-22,

[40] Lee JM, Park DG, Kang SS, Choi EJ, Gwon HS, Lee HS, Lee SI. Short-term effect of biochar on soil organic carbon improvement and nitrous oxide emission reduction according to different soil characteristics in agricultural land: a laboratory experiment. Agronomy, 2022, 12(8): 1879,

[41] Li S, Wang S, Shangguan Z. Combined biochar and nitrogen fertilization at appropriate rates could balance the leaching and availability of soil inorganic nitrogen. Agric Ecosyst Environ, 2019, 276: 21-30,

[42] Li X, Xu S, Neupane A, Abdoulmoumine N, DeBruyn JM, Walker FR, Jagadamma S. Co-application of biochar and nitrogen fertilizer reduced nitrogen losses from soil. PLoS ONE, 2021, 16(3),

[43] Li C, Zhao C, Zhao X, Wang Y, Lv X, Zhu X, Song X. Beneficial effects of biochar application with nitrogen fertilizer on soil nitrogen retention, absorption and utilization in maize production. Agronomy, 2023, 13(1): 113,

[44] Liao J, Liu X, Hu A, Song H, Chen X, Zhang Z. Effects of biochar-based controlled release nitrogen fertilizer on nitrogen-use efficiency of oilseed rape (Brassica napus L.). Sci Rep, 2020, 10: 1-14,

[45] Li-li H, Zhong ZK, Yang HM. Effects on soil quality of biochar and straw amendment in conjunction with chemical fertilizers. J Integr Agric, 2017, 16: 704-712,

[46] Liu Y, Chen J. Effect of ageing on biochar properties and pollutant management. Chemosphere, 2022, 292,

[47] Liu CW, Sung Y, Chen BC, Lai HY. Effects of nitrogen fertilizers on the growth and nitrate content of lettuce (Lactuca sativa L.). Int J Environ Res Public Health, 2014, 11(4): 4427-4440,

[48] Liu Z, He T, Cao T, Yang T, Meng J, Chen W. Effects of biochar application on nitrogen leaching, ammonia volatilization and nitrogen use efficiency in two distinct soils. J Soil Sci Plant Nutr, 2017, 17(2): 515-528,

[49] Lugato E, Berti A, Giardini L. Soil organic carbon (SOC) dynamics with and without residue incorporation in relation to different nitrogen fertilisation rates. Geoderma, 2006, 135: 315-321,

[50] Mahmood F, Khan I, Ashraf U, Shahzad T, Hussain S, Shahid M, Abid M, Ullah S. Effects of organic and inorganic manures on maize and their residual impact on soil physico-chemical properties. J Soil Sci Plant Nutr, 2017, 17: 22-32,

[51] Marcińczyk M, Oleszczuk P. Biochar and engineered biochar as slow-and controlled-release fertilizers. J Cleaner Prod, 2022, 339,

[52] Martin SL, Clarke ML, Othman M, Ramsden SJ, West HM. Biochar-mediated reductions in greenhouse gas emissions from soil amended with anaerobic digestates. Biomass Bioenergy, 2015, 79: 39-49,

[53] Matin NH, Jalali M, Antoniadis V, Shaheen SM, Wang J, Zhang T, Rinklebe J. Almond and walnut shell-derived biochars affect sorption-desorption, fractionation, and release of phosphorus in two different soils. Chemosphere, 2020, 241,

[54] McMillan C, Boardman R, McKellar M, Sabharwall P, Ruth M, Bragg-Sitton S. Generation and use of thermal energy in the US Industrial sector and opportunities to reduce its carbon emissions. National Renewable Energy Lab.(NREL), Golden, CO (United States). 2016. Report No.: NREL/TP-6A50-66763; INL/EXT-16-39680. https://doi.org/10.2172/1334495

[55] Mehmood I, Qiao L, Chen H, Tang Q, Woolf D, Fan M. Biochar addition leads to more soil organic carbon sequestration under a maize-rice cropping system than continuous flooded rice. Agric Ecosyst Environ, 2020, 298,

[56] Melo LCA, Lehmann J, Carneiro JSDS, Camps-Arbestain M. Biochar-based fertilizer effects on crop productivity: a meta-analysis. Plant Soil, 2022, 472(1–2): 45-58,

[57] Murtaza G, Ahmed Z, Valipour M, Ali I, Usman M, Iqbal R, Zulfiqar U, Rizwan M, Mahmood S, Ullah A, Arslan M. Recent trends and economic significance of modified/functionalized biochars for remediation of environmental pollutants. Sci Rep, 2024, 14(1): 217,

[58] Nagappan S, Devendran S, Tsai PC, Jayaraman H, Alagarsamy V, Pugazhendhi A, Ponnusamy VK. Metabolomics integrated with transcriptomics and proteomics: evaluation of systems reaction to nitrogen deficiency stress in microalgae. Process Biochem, 2020, 91: 1-14,

[59] Neff JC, Townsend AR, Gleixner G, Lehman SJ, Turnbull J, Bowman WD. Variable effects of nitrogen additions on the stability and turnover of soil carbon. Nature, 2002, 419: 915-917,

[60] Oladele S, Adeyemo A, Awodun M, Ajayi A, Fasina A. Effects of biochar and nitrogen fertilizer on soil physicochemical properties, nitrogen use efficiency and upland rice (Oryza sativa) yield grown on an Alfisol in Southwestern Nigeria. Int J Recycl Org Waste Agric, 2019, 8: 295-308,

[61] Oni BA, Oziegbe O, Olawole OO. Significance of biochar application to the environment and economy. Ann Agric Sci, 2019, 64: 222-236,

[62] Pawlak K, Kołodziejczak M. The role of agriculture in ensuring food security in developing countries: considerations in the context of the problem of sustainable food production. Sustainability, 2020, 12: 5488,

[63] Peng J, Han X, Li N, Chen K, Yang J, Zhan X, Luo P, Liu N. Combined application of biochar with fertilizer promotes nitrogen uptake in maize by increasing nitrogen retention in soil. Biochar, 2021, 3: 367-379,

[64] Phares CA, Amoakwah E, Danquah A, Akaba S, Frimpong KA, Mensah TA. Improved soil physicochemical, biological properties and net income following the application of inorganic NPK fertilizer and biochar for maize production. Acta Ecol Sin, 2022, 42: 289-295,

[65] Rehman RA, Rizwan M, Qayyum MF, Ali S, Zia-ur-Rehman M, Zafar-ul-Hye M, Hafeez F, Iqbal MF. Efficiency of various sewage sludges and their biochars in improving selected soil properties and growth of wheat (Triticum aestivum L.). J Environ Manag, 2018, 223: 607-613,

[66] Robson AD, Snowball K, Robson AD. Soil acidity and plant growth. Soil Sci, 1989, 150(6): 903,

[67] Roß CL, Baumecker M, Ellmer F, Kautz T. Organic manure increases carbon sequestration far beyond the “4 per 1000 Initiative” goal on a sandy soil in the Thyrow long-term field experiment DIV. 2. Agriculture, 2022, 12(2): 170,

[68] Sarfraz R, Shakoor A, Abdullah M, Arooj A, Hussain A, Xing S. Impact of integrated application of biochar and nitrogen fertilizers on maize growth and nitrogen recovery in alkaline calcareous soil. Soil Sci Plant Nutr, 2017, 63(5): 488-498,

[69] Shen J, Li R, Zhang F, Fan J, Tang C, Rengel Z. Crop yields, soil fertility and phosphorus fractions in response to long-term fertilization under the rice monoculture system on a calcareous soil. Field Crop Res, 2004, 86(2–3): 225-238,

[70] Sial TA, Liu J, Zhao Y, Khan MN, Lan Z, Zhang J, Kumbhar F, Akhtar K, Rajpar I. Co-application of milk tea waste and NPK fertilizers to improve sandy soil biochemical properties and wheat growth. Molecules, 2019, 24(3): 423,

[71] Šimanský V, Šrank D. Relationships between soil organic matter and crop yield after biochar substrates application and their combination with mineral fertilizers on sandy soil. Acta Horticulturae Et Regiotecturae, 2021, 24(1): 14-20,

[72] Šimanský V, Horák J, Polláková N, Juriga M, Jonczak J. Will the nutrient content in biochar be reflected by their higher content of corn organs?. J Elem, 2019, 24(2): 525-537,

[73] Su YZ, Wang F, Suo DR, Zhang ZH, Du MW. Long-term effect of fertilizer and manure application on soil-carbon sequestration and soil fertility under the wheat–wheat–maize cropping system in northwest China. Nutr Cycl Agroecosyst, 2006, 75: 285-295,

[74] Sun Z, Hu Y, Shi L, Li G, Han J, Pang Z, Liu S, Chen Y, Jia B. Effects of biochar on soil chemical properties: a global meta-analysis of agricultural soil. Plant Soil Environ, 2022, 68(6): 272-289,

[75] Sutton MA, Howard CM, Mason KE, Brownlie WJ, Cordovil C. Nitrogen opportunities for agriculture, food & environment. UNECE guidance document on integrated sustainable nitrogen management. 2022.

[76] Tian J, Lou Y, Gao Y, Fang H, Liu S, Xu M, Blagodatskaya E, Kuzyakov Y. Response of soil organic matter fractions and composition of microbial community to long-term organic and mineral fertilization. Biol Fertil Soils, 2017, 53: 523-532,

[77] Tian S, Tan Z, Kasiulienė A, Ai P. Transformation mechanism of nutrient elements in the process of biochar preparation for returning biochar to soil. Chin J Chem Eng, 2017, 25: 477-486,

[78] Toková L, Igaz D, Horák J, Aydin E. Effect of biochar application and re-application on soil bulk density, porosity, saturated hydraulic conductivity, water content and soil water availability in a silty loam Haplic Luvisol. Agronomy, 2020, 10: 1005,

[79] Ullah S, Liang H, Ali I, Zhao Q, Iqbal A, Wei S, Shah T, Yan B, Jiang L. Biochar coupled with contrasting nitrogen sources mediated changes in carbon and nitrogen pools, microbial and enzymatic activity in paddy soil. J Saudi Chem Soc, 2020, 24: 835-849,

[80] Xiu L, Zhang W, Wu D, Sun Y, Zhang H, Gu W, Wang Y, Meng J, Chen W. Biochar can improve biological nitrogen fixation by altering the root growth strategy of soybean in Albic soil. Sci Total Environ, 2021, 773,

[81] Xu RK, Zhao AZ, Yuan JH, Jiang J. pH buffering capacity of acid soils from tropical and subtropical regions of China as influenced by incorporation of crop straw biochars. J Soils Sed, 2012, 12: 494-502,

[82] Yu L, Lu X, He Y, Brookes PC, Liao H, Xu J. Combined biochar and nitrogen fertilizer reduces soil acidity and promotes nutrient use efficiency by soybean crop. J Soils Sed, 2017, 17: 599-610,

[83] Yuen SH, Pollard AG. Determination of nitrogen in agricultural materials by the Nessler reagent. II. Micro-determinations in plant tissue and in soil extracts. J Sci Food Agric, 1954, 5: 364-369,

[84] Zavalloni C, Alberti G, Biasiol S, Delle Vedove G, Fornasier F, Liu J, Peressotti A. Microbial mineralization of biochar and wheat straw mixture in soil: a short-term study. Appl Soil Ecol, 2011, 50: 45-51,

[85] Zhang M, Riaz M, Zhang L, El-Desouki Z, Jiang C. Biochar induces changes to basic soil properties and bacterial communities of different soils to varying degrees at 25 mm rainfall: more effective on acidic soils. Front Microbiol, 2019, 10: 1321,

[86] Zhou W, Han G, Liu M, Li X. Effects of soil pH and texture on soil carbon and nitrogen in soil profiles under different land uses in Mun River Basin, Northeast Thailand. PeerJ, 2019, 7,

Funding

Vedecká Grantová Agentúra M?VVa? SR a SAV(1/0021/22); Agentúra na Podporu Vyskumu a Vyvoja(APVV-21-0089); Opera?ny program Integrovaná infra?truktúra(313011W112); Linnaeus University