Increased erosion in biochar-amended soil: importance of integrating erosion control blankets and vegetation

Abstract

Although biochar is widely recognized for enhancing various soil properties, its impact on soil erosion resistance remains unclear and sometimes shows contradictory results. The main objective of this study is to quantify the effects of corn-cob biochar amendment, both with and without erosion control blankets (ECB), as well as the influence of biochar/compost incubation time on erosion resistance of a silty sand. The study also investigates the effects of biochar on Atterberg limits, shear strength, and thermal conductivity. As biochar content increases from 0 % to 20 %, the liquid limit (LL), plastic limit (PL), and shrinkage limit (SL) rise by 8 %-10 %, suggesting that biochar-amended soil (BAS) retains more water without losing strength. The addition of biochar has minimal impact on the shear strength of BAS at lower normal stresses (<45 kPa) but reduces its thermal conductivity by about 70 %. Submerged jet erosion tests show that biochar alone increases soil erosion in BAS. However, when combined with ECB and vegetation, erosion is significantly reduced (up to 39 %). Overall, this study underscores the importance of utilizing biochar in combination with ECB and such vegetation as ruzi grass to mitigate soil erosion in the silty sand.

Keywords

Tropical soil / Biochar / Erosion / Erosion control blanket / Thermal conductivity / Submerged jet erosion test

CRediT authorship contribution statement

Monir Hossain: Writing - original draft, Visualization, Investigation, Formal analysis, Data curation, Conceptualization. Apiniti Jotisankasa: Writing - review & editing, Writing - original draft, Validation, Supervision, Resources, Project administration, Methodology, Funding acquisition, Conceptualization. Surachet Aramrak: Writing - review & editing, Supervision. Viroon Kamchoom: Writing - review & editing. Satoshi Nishimura: Writing - review & editing, Supervision, Resources, Funding acquisition. Supakij Nontananandh: Writing - review & editing, Supervision. Tananop Muanlhao: Investigation. Surat Semmad: Writing - review & editing, Supervision, Methodology.

Data Availability

Data for the formal analysis are presented in the article. Raw data are available upon request from the corresponding author.

Declaration of Competing Interest

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Apiniti Jotisankasa reports equipment, drugs, or supplies was provided by Japan International Cooperation Agency. Apiniti Jotisankasa reports a relationship with Green Ground Solutions, co Ltd that includes: board membership and equity or stocks. The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

The first author expresses his gratitude for the grant provided by the Department of Civil Engineering and Faculty of Engineering, Kasetsart University. The authors also acknowledge the research grant from Kasetsart University Research and Development Institute, KURDI (Project no. FF(KU-SRIU)4.67) for the additional fund. Appreciation is also extended to the JICA/JST SATREPS project for the supports of equipments and facilitating collaborative work between Hokkaido University and Kasetsart University. The students and staff at the Geotechnical Division of the Department of Civil Engineering at Kasetsart University and Green Ground Solutions, Co. Ltd., are also thanked for their support.

References

[1] Abel, S., Peters, A., Trinks, S., Schonsky, H., Facklam, M., & Wessolek, G. (2013). Impact of biochar and hydrochar addition on water retention and water repellency of sandy soil. Geoderma, 202, 183-191. https://doi.org/10.1016/j.geoderma.2013.03.003

[2] Abrol, V., Ben-Hur, M., Verheijen, F. G., Keizer, J. J., Martins, M. A., Tenaw, H., Tchehansky, L., & Graber, E. R. (2016). Biochar effects on soil water infiltration and erosion under seal formation conditions: Rainfall simulation experiment. Journal Soils Sediments, 16, 2709-2719. https://doi.org/10.1007/s11368-016-1448-8

[3] Adeniyi, A. G., Iwuozor, K. O., Muritala, K. B., Emenike, E. C., & Adeleke, J. A. (2023). Conversion of biomass to biochar using top-lit updraft technology: A review. Biofuels, Bioproducts and Biorefining, 17( 5), 1411-1424. https://doi.org/10.1002/bbb.2497

[4] ASTM. (2012). Standard test method for direct shear test of soils under consolidated drained conditions. In ASTM D3080-04. West Conshohocken, PA: ASTM International.

[5] ASTM. (2017a). Standard test method for determination of thermal conductivity of soil and soft rock by thermal needle probe procedure. In ASTM D5334-00. West Conshohocken, PA: ASTM International.

[6] ASTM. (2017b). Standard test method for measuring mass per unit area of erosion control blankets. In ASTM D6475-17. West Conshohocken, PA: ASTM International.

[7] ASTM. (2018). Standard practice for classification of soils for engineering purposes (Unified Soil Classification System). In ASTM D2487-11. West Conshohocken, PA: ASTM International.

[8] ASTM International (2021). Standard test method for tensile properties of rolled erosion control products. In ASTM D6818-21. West Conshohocken, PA: ASTM International.

[9] ASTM. (2023). Standard test method for measuring nominal thickness of rolled erosion control products. In ASTM D6525/D6525M-18. West Conshohocken, PA: ASTM International.

[10] Apriyono, A., Yuliana Z. Chen, Keawsawasvong, S., & Kamchoom, V. (2024). The impact of biochar amendment on soil water infiltration and evaporation under climate change scenarios. Acta Geophysics, 72, 3647-3660. https://doi.org/10.1007/s11600-024-01289-4

[11] Atkinson, J. H., & Bransby, P. L. (1978). The mechanics of soils - An introduction to critical state soil mechanics. London: McGraw Hill Book Co.

[12] Beheshti, M., Etesami, H., & Alikhani, H. A. (2018). Effect of different biochar amendments on soil biological indicators in a calcareous soil. Environmental Science and Pollution Research, 25, 14752-14761. https://doi.org/10.1007/s11356-018-1682-2

[13] Bolan, N., Hou, D., Wang, L., Hale, L., Egamberdieva, D., Tammeorg, P., Li, R., Wang, B., Xu, J., Wang, T., Sun, H., Padhye, L. P., Wang, H., Siddique, K. H. M., Rinklebe, J., Kirkham, M. B., & Bolan, N. (2023). The potential of biochar as a microbial carrier for agricultural and environmental applications. Science Total Environment, 886, Article 163968. https://doi.org/10.1016/j.scitotenv.2023.163968

[14] Bordoloi, S., Garg, A., Sreedeep, S., Lin, P., & Mei, G. (2018). Investigation of cracking and water availability of soil-biochar composite synthesized from invasive weed water hyacinth. Bioresources Technology, 263, 665-677. https://doi.org/10.1016/j.biortech.2018.05.011

[15] Bordoloi, S., & Ng, C. W. W. (2020). The effects of vegetation traits and their stability functions in bio-engineered slopes: A perspective review. Engineering Geology, 275, Article 105742. https://doi.org/10.1016/j.enggeo.2020.105742

[16] Briaud, J. L., Govindasamy, A. V., & Shafii, I. (2017). Erosion charts for selected geomaterials. Journal of Geotechnical and Geoenvironmental Engineering, 143(10), Article 04017072. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001771

[17] Brtnicky, M., Datta, R., Holatko, J., Bielska, L., Gusiatin, Z. M., Kucerik, J., Hammerschmiedt, T., Danish, S., Radziemska, M., Mravcova, L., Fahad, S., Kintl, A., Sudoma, M., Ahmed, N., & Pecina, V. (2021). A critical review of the possible adverse effects of biochar in the soil environment. Science of the Total Environment, 796, Article 148756. https://doi.org/10.1016/j.scitotenv.2021.148756

[18] Cedeño, Á., Olmo, M., Cedeño, G., Lucas, M., Saldarriaga, V., & Villar, R. (2024). Effects of different biochar types on the growth and functional traits of rice (Oryza sativa L). Journal of Ecological Engineering, 25(3), 282-290. https://doi.org/10.12911/22998993/182868

[19] Chen, Z., Kamchoom, V., & Chen, R. (2022). Landfill gas emission through compacted clay considering effects of crack pathway and intensity. Waste Management, 143, 215-222. https://doi.org/10.1016/j.wasman.2022.02.032

[20] Chen, Z., Kamchoom, V., Leung, A. K., Xue, J., & Chen, R. (2023a). Influence of biochar on the water permeability of compacted clay subjected to freezing-thawing cycles. Acta Geophysics, 1-11. https://doi.org/10.1007/s11600-023-01141-1

[21] Chen, Z., Kamchoom, V., Chen, R., & Prasittisopin, L. (2023b). Investigating the impacts of biochar amendment and soil compaction on unsaturated hydraulic properties of silty sand. Agronomy, 13(7), 1845. https://doi.org/10.3390/agronomy13071845

[22] Daly, E. R., Miller, R. B., & Fox, G. A. (2015). Modeling streambank erosion and failure along protected and unprotected composite streambanks. Advances in Water Resources, 81, 114-127. https://doi.org/10.1016/j.advwatres.2015.01.004

[23] Das, O., Sarmah, A. K., & Bhattacharyya, D. (2015). Structure-mechanics property relationship of waste derived biochars. Science Total Environment, 538, 611-620. https://doi.org/10.1016/j.scitotenv.2015.08.073

[24] Das, S. K., & Ghosh, G. K. (2023). Developing biochar-based slow-release NPK fertilizer for controlled nutrient release and its impact on soil health and yield. Biomass Conversion Biorefinery, 13(14), 13051-13063. https://doi.org/10.1007/s13399-021-02069-6

[25] Doan, T. T., Henry-des-Tureaux, T., Rumpel, C., Janeau, J.-L., & Jouquet, P. (2015). Impact of compost, vermicompost and biochar on soil fertility, maize yield and soil erosion in Northern Vietnam: A three-year mesocosm experiment. Science Total Environment, 514, 147-154. https://doi.org/10.1016/j.scitotenv.2015.02.005

[26] Faloye, O. T., Ajayi, A. E., Kamchoom, V., Akintola, O. A., & Oguntunde, P. G. (2024). Evaluating the impact of biochar and inorganic fertilizer applications on maize yield using multivariate statistical approach. Agronomy, 14(8), 1761. https://doi.org/10.3390/agronomy14081761

[27] Garg, A., Huang, H., Kushvaha, V., Madhushri, P., Kamchoom, V., Wani, I.,... Zhu, H. H. (2020). Mechanism of biochar soil pore-gas-water interaction: gas properties of biochar-amended sandy soil at different degrees of compaction using KNN modeling. Acta Geophysics, 68, 207-217. https://doi.org/10.1007/s11600-019-00387-y

[28] W. Goldsmith M. Silva C. Fischenich Determining optimal degree of soil compaction for balancing mechanical stability and plant growth capacity ERDC TN-EMRRP-SR-26, 2001 U.S. Army Engineer Research and Development Center Vicksburg, MS.

[29] Gopal, P., Bordoloi, S., Ratnam, R., Lin, P., Cai, W., Buragohain, P., Garg, A., & Sreedeep, S. (2019). Investigation of infiltration rate for soil-biochar composites of water hyacinth. Acta Geophysics, 67, 231-246. https://doi.org/10.1007/s11600-018-0237-8

[30] Gray, D. H. (2002). Optimizing soil compaction. Erosion Control, 9, 34-41.

[31] Han, L., Zhang, B., Chen, L., Feng, Y., Yang, Y., & Sun, K. (2021). Impact of biochar amendment on soil aggregation varied with incubation duration and biochar pyrolysis temperature. Biochar, 3(3), 339-347. https://doi.org/10.1007/s42773-021-00097-z

[32] Hanson, G. J. (1990). Surface erodibility of earthen channels at high stresses part II- developing an in situ testing device. Transactions of the ASAE, 33(1), 132-137. https://doi.org/10.13031/2013.31306

[33] Hanson, G. J. (1991). Development of a jet index to characterize erosion resistance of soils in earthen spillways. Transactions of the ASAE, 34(5), 2015-2020. https://doi.org/10.13031/2013.31831

[34] Hanson, G., & Cook, K. (1999). Procedure to estimate soil erodibility for water management purposes, In Am. Soc. Agric. Eng. Pap. 992133. Proc. Mini-Conf. Advances in Water Quality Modeling, 51-56.

[35] Hanson, G. J., & Simon, A. (2001). Erodibility of cohesive streambeds in the loess area of the midwestern USA. Hydrological processes, 15(1), 23-38. https://doi.org/10.1002/hyp.149

[36] Hanson, G. J., Robinson, K. M., & Cook, K. R. (2002). Scour below an overfall: Part II. Prediction. Transactions of the ASAE, 45(4), 957. https://doi.org/10.13031/2013.9948

[37] Hossain, M., Jotisankasa, A., Aramrak, S., Nishimura, S., & Yodsudyai, W. (2024). Influence of biochar on unsaturated hydraulic characteristics of a tropical residual silty sand. International Journal of Geosynthetics and Ground Engineering, 10, 78. https://doi.org/10.1007/s40891-024-00588-6

[38] Hseu, Z. Y., Jien, S. H., Chien, W. H., & Liou, R. C. (2014). Impacts of biochar on physical properties and erosion potential of a mudstone slopeland soil. Science World Journal, 2014(1), Article 602197. https://doi.org/10.1155/2014/602197

[39] Hussain, R., Ravi, K., & Garg, A. (2020). Influence of biochar on the soil water retention characteristics (SWRC): Potential application in geotechnical engineering structures. Soil Tillage Research, 204, Article 104713. https://doi.org/10.1016/j.still.2020.104713

[40] Hutchison, D. L. (1972). Physics of erosion of cohesive soils. New Zealand: University of Auckland.

[41] Jayawardhana, Y., Kumarathilaka, P., Herath, I., & Vithanage, M. (2016). Municipal solid waste biochar for prevention of pollution from landfill leachate. In environmental materials and waste. Academic Press, 117-148. https://doi.org/10.1016/B978-0-12-803837-6.00006-8

[42] Jien, S. H., & Wang, C. S. (2013). Effects of biochar on soil properties and erosion potential in a highly weathered soil. Catena, 110, 225-233. https://doi.org/10.1016/j.catena.2013.06.021

[43] Jotisankasa, A., Mahannopkul, K., & Sawangsuriya, A. (2015). Slope stability and pore- water pressure regime in response to rainfall: A case study of granitic fill slope in northern Thailand. Journal of Geotechnical & Geoenvironmental Engineering SEAGS AGSSEA, 46(1), 45-54.

[44] Jotisankasa, A., Sawangsuriya, A., Muanlhao, T., & Nishimura, S. (2023). Application of nature-based solution for resilient and sustainable slopes in Thailand. Prosiding KRTJ HPJI, 16(1), 1-13.

[45] Kamchoom, V., Leung, A. K., Boldrin, D., Sakolpanya, T., & Likitlersuang, S. (2022). Shearing behaviour of vegetated soils with growing and decaying roots. Canadian Geotechnical Journal, 59(12), 2067-2084. https://doi.org/10.1139/cgj-2021-0695

[46] Kookana, R. S., Sarmah, A. K., Van Zwieten, L., Krull, E., & Singh, B. (2011). Biochar application to soil: Agronomic and environmental benefits and unintended consequences. Advance Agronomy, 112, 103-143. https://doi.org/10.1016/B978-0-12-385538-1.00003-2

[47] Kumar, H., Ganesan, S. P., Bordoloi, S., Sreedeep, S., Lin, P., Mei, G., Garg, A., & Sarmah, A. K. (2019). Erodibility assessment of compacted biochar amended soil for geo-environmental applications. Science Total Environment, 672, 698-707. https://doi.org/10.1016/j.scitotenv.2019.03.417

[48] Li, Y., Zhang, F., Yang, M., Zhang, J., & Xie, Y. (2019). Impacts of biochar application rates and particle sizes on runoff and soil loss in small cultivated loess plots under simulated rainfall. Science Total Environment, 649, 1403-1413. https://doi.org/10.1016/j.scitotenv.2018.08.415

[49] Lin, Y., Cai, Q., Chen, B., & Garg, A. (2024). A review of the negative effects of biochar on soil in green infrastructure with consideration of soil properties. Indian Geotechnical Journal, 1-15. https://doi.org/10.1007/s40098-024-00875-z

[50] Liu, B., Li, H., Li, H., Zhang, A., & Rengel, Z. (2021). Long-term biochar application promotes rice productivity by regulating root dynamic development and reducing nitrogen leaching. GCB Bioenergy, 13(1), 257-268. https://doi.org/10.1111/gcbb.12766

[51] Mahannopkul, K., & Jotisankasa, A. (2019). Influences of root concentration and suction on Chrysopogon zizanioides reinforcement of soil. Soils Found, 59(2), 500-516. https://doi.org/10.1016/j.sandf.2018.12.014

[52] Mairaing, W., Jotisankasa, A., Leksungnoen, N., Hossain, M., Ngernsaengsaruay, C., Rangsiwanichpong, P., Pilumwong, J., Pramusandi, S., Semmad, S., & Ahmmed, A. N. F. (2024). A biomechanical study of potential plants for erosion control and slope stabilization of highland in Thailand. Sustainability, 16(15), 6374. https://doi.org/10.3390/su16156374

[53] Montgomery, D. R. (2007). Soil erosion and agricultural sustainability. Proceedings of the National Academy of Sciences, 104(33), 13268-13272. https://doi.org/10.1073/pnas.0611508104

[54] Muntohar, A. S., Ikhsan, J., Liao, H. J., Jotisankasa, A., & Jetten, V. G. (2022). Rainfall infiltration-induced slope instability of the unsaturated volcanic residual soils during wet seasons in Indonesia. Indonesian Journal on Geoscience, 9(1), 71-85. https://doi.org/10.17014/ijog.9.1.71-85

[55] Ng, C. W. W., Leung, A. K., & Woon, K. (2014). Effects of soil density on grass-induced suction distributions in compacted soil subjected to rainfall. Canadian Geotechnical Journal, 51(3), 311-321. https://doi.org/10.1139/cgj-2013-0221

[56] Ni, J., Chen, X., Ng, C. W. W., & Guo, H. (2018). Effects of biochar on water retention and matric suction of vegetated soil. Géotechnique Letters, 8(2), 124-129. https://doi.org/10.1680/jgele.17.00180

[57] Ongpaporn, P., Jotisankasa, A., & Likitlersuang, S. (2022). Geotechnical investigation and stability analysis of bio-engineered slope at Surat Thani Province in Southern Thailand. Bulletin of Engineering Geology and the Environment, 81, 84. https://doi.org/10.1007/s10064-022-02591-5

[58] Pandit, N. R., Mulder, J., Hale, S. E., Zimmerman, A. R., Pandit, B. H., & Cornelissen, G. (2018). Multi-year double cropping biochar field trials in Nepal: Finding the optimal biochar dose through agronomic trials and cost-benefit analysis. Science Total Environment, 637-638, 1333-1341. https://doi.org/10.1016/j.scitotenv.2018.05.107

[59] Prats, S., Merino, A., González-Pérez, J. A., Verheijen, F., & De la Rosa, J. (2021). Can straw-biochar mulching mitigate erosion of wildfire-degraded soils under extreme rainfall? Science Total Environment, 761, Article 143219. https://doi.org/10.1016/j.scitotenv.2020.143219

[60] Rahardjo, H., Kim, Y., & Satyanaga, A. (2019). Role of unsaturated soil mechanics in geotechnical engineering. International Journal of Geo-Engineering, 10, 1-23. https://doi.org/10.1186/s40703-019-0104-8

[61] Rajamanthri, K., Jotisankasa, A., & Aramrak, S. (2021). Effects of Chrysopogon zizanioides root biomass and plant age on hydro-mechanical behavior of root-permeated soils. International Journal of Geosynthetics and Ground Engineering, 7(2), 36. https://doi.org/10.1007/s40891-021-00271-0

[62] Reddy, K. R., Yaghoubi, P., & Yukselen-Aksoy, Y. (2015). Effects of biochar amendment on geotechnical properties of landfill cover soil. Waste Management Research, 33(6), 524-532. https://doi.org/10.1177/0734242X15580192

[63] Reubens, B., Poesen, J., Danjon, F., Geudens, G., & Muys, B. (2007). The role of fine and coarse roots in shallow slope stability and soil erosion control with a focus on root system architecture: A review. Trees, 21(4), 385-402. https://doi.org/10.1007/s00468-007-0132-4

[64] Sadasivam, B. Y., & Reddy, K. R. (2015). Shear strength of waste-wood biochar and biochar- amended soil used for sustainable landfill cover systems. IOS Press745-752. https://doi.org/10.3233/978-1-61499-603-3-745

[65] Sadeghi, S. H., Hazbavi, Z., & Harchegani, M. K. (2016). Controllability of runoff and soil loss from small plots treated by vinasse-produced biochar. Science Total Environment, 541, 483-490. https://doi.org/10.1016/j.scitotenv.2015.09.068

[66] Schmidt, K., Roering, J., Stock, J., Dietrich, W., Montgomery, D., & Schaub, T. (2001). The variability of root cohesion as an influence on shallow landslide susceptibility in the Oregon Coast Range. Canadian Geotechnical Journal, 38(5), 995-1024. https://doi.org/10.1139/cgj-38-5-995

[67] Semmad, S., Chup-uppakan, T., & Chalermyanont, T. (2019). An alternative method for determining erosion parameters related to non-linear model; based on submerged jet erosion test. GEOMATE Journal, 16(53), 53-61.

[68] Semmad, S., Jotisankasa, A., Mahannopkul, K., & Inazumi, S. (2022). A coupled simulation of lateral erosion, unsaturated seepage and bank instability due to prolonged high flow. Geomechanics for Energy and the Environment, 32, Article 100301. https://doi.org/10.1016/j.gete.2021.100301

[69] Senanayake, S., Pradhan, B., Wedathanthirige, H., Alamri, A., & Park, H.-J. (2024). Monitoring soil erosion in support of achieving SDGs: A special focus on rainfall variation and farming systems vulnerability. CATENA, 234, Article 107537. https://doi.org/10.1016/j.catena.2023.107537

[70] Sharma, B., & Bora, P. K. (2003). Plastic limit, liquid limit, and undrained shear strength of soil—Reappraisal. Journal of Geotechnical and Geoenvironmental Engineering, 129(8), 774-777. https://doi.org/10.1061/(ASCE)1090-0241(2003)129:8(774)

[71] Sohi, S. P., Krull, E., Lopez-Capel, E., & Bol, R. (2010). A review of biochar and its use and function in soil. Advance Agronomy, 105, 47-82. https://doi.org/10.1016/S0065-2113(10)05002-9

[72] Steinbeiss, S., Gleixner, G., & Antonietti, M. (2009). Effect of biochar amendment on soil carbon balance and soil microbial activity. Soil Biology Biochemistry, 41(6), 1301-1310. https://doi.org/10.1016/j.soilbio.2009.03.016

[73] Stormont, J. (1996). The effectiveness of two capillary barriers on a 10% slope. Geotechnical and Geological Engineering, 14, 243-267. https://doi.org/10.1007/BF00421943

[74] Ulyett, J., Sakrabani, R., Kibblewhite, M., & Hann, M. (2014). Impact of biochar addition on water retention, nitrification and carbon dioxide evolution from two sandy loam soils. European Journal of Soil Science, 65(1), 96-104. https://doi.org/10.1111/ejss.12081

[75] Usowicz, B., Lipiec, J., Łukowski, M., Marczewski, W., & Usowicz, J. (2016). The effect of biochar application on thermal properties and albedo of loess soil under grassland and fallow. Soil Tillage Research, 164, 45-51. https://doi.org/10.1016/j.still.2016.03.009

[76] Weber, K., & Quicker, P. (2018). Properties of biochar. Fuel, 217, 240-261. https://doi.org/10.1016/j.fuel.2017.12.054

[77] Wong, J. T. F., Chen, Z., Chen, X., Ng, C. W. W., & Wong, M. H. (2017). Soil-water retention behavior of compacted biochar-amended clay: a novel landfill final cover material. Journal Soils Sediments, 17, 590-598. https://doi.org/10.1007/s11368-016-1401-x

[78] Wong, J. T. F., Chen, Z., Ng, C. W. W., & Wong, M. H. (2016). Gas permeability of biochar-amended clay: potential alternative landfill final cover material. Environment Science Pollution Research, 23, 7126-7131. https://doi.org/10.1007/s11356-015-4871-2

[79] Wong, J. T. F., Chen, Z., Wong, A. Y. Y., Ng, C. W. W., & Wong, M. H. (2018). Effects of biochar on hydraulic conductivity of compacted kaolin clay. Environment Pollution, 234, 468-472. https://doi.org/10.1016/j.envpol.2017.11.079

[80] Yu, L., Tang, J., Zhang, R., Wu, Q., & Gong, M. (2013). Effects of biochar application on soil methane emission at different soil moisture levels. Biology and Fertility of Soils, 49, 119-128. https://doi.org/10.1007/s00374-012-0703-4

[81] Zuazo, V. D., Pleguezuelo, C. R., Peinado, F. M., De Graaff, J., Martínez, J. F., & Flanagan, D. C. (2011). Environmental impact of introducing plant covers in the taluses of terraces: Implications for mitigating agricultural soil erosion and runoff. Catena, 84(1-2), 79-88. https://doi.org/10.1016/j.catena.2010.10.004

[82] Zhang, Q., Wang, Y., Wu, Y., Wang, X., Du, Z., Liu, X., & Song, J. (2013). Effects of biochar amendment on soil thermal conductivity, reflectance, and temperature. Soil Science Society. America Journal, 77(5), 1478-1487. https://doi.org/10.2136/sssaj2012.0180

[83] Zhao, J., Ren, T., Zhang, Q., Du, Z., & Wang, Y. (2016). Effects of biochar amendment on soil thermal properties in the North China Plain. Soil Science Society. America Journal, 80(5), 1157-1166. https://doi.org/10.2136/sssaj2016.01.0020