Geochemical Modelling of Inorganic Nutrients Leaching from an Agricultural Soil Amended with Olive-Mill Waste Biochar

Agronomy

Salah Jellali¹  Zacharenia Kypritidou²  Mejdi Jeguirim³  Evangelos Tziritis⁴  Vasiliki Kinigopoulou⁴  Charalampos Doulgeris⁴ 

[1] Center for Environmental Studies and Research, Sultan Qaboos University, P.O. Box 33, Al-Khod 123, Oman;Department of Economic Geology and Geochemistry, Faculty of Geology and Geo-Environment, National & Kapodistrian University of Athens, 15784 Athens, Greece;Institut de Science des Matériaux de Mulhouse (IS2M), CNRS, Université de Haute-Alsace, UMR 7361, F-68100 Mulhouse, France;Soil and Water Resources Institute (SWRI), Hellenic Agricultural Organisation, 57400 Thessaloniki, Greece;

关键词: biochar;    olive mill wastes;    potassium;    column experiments;    kinetics;    ion-exchange;   

DOI  :  10.3390/agronomy12020480

来源: DOAJ

【 摘 要 】

This work examines in silico the dominant geochemical processes that control inorganic nutrients (Ca, Mg, Na, K) availability in irrigated agricultural soil amended with potassium-enriched biochar (from olive mill wastes) at mass doses of 0.5%, 1%, 2% and 10%. The geochemical modelling step was supported by analytical measurements regarding the physicochemical characteristics of the irrigation water, the agricultural soil and the biochar. Two geochemical approaches, namely equilibrium exchange (E.E.) and kinetic exchange (K.E.) models were applied and compared to assess nutrient release with an emphasis on potassium availability. Equilibrium exchange perspective assumed that nutrient release is controlled by ion-exchange reactions onto the biochar surface, whilst kinetic exchange perspective assumed the contribution of both ion-exchange and dissolution of salts. Results indicated that for the E.E. model, the soluble amount of potassium is readily available for transport within the pores of the porous media, and therefore is leached from the column within only 10 days. For the K.E. model that assumes a kinetically controlled release of potassium due to interactions occurring at the solid-solution interface, the assessed retention times were more realistic and significantly higher (up to 100 days). Concerning the applied doses of biochar, for a 2% biochar fraction mixed with soil, for example, the available K for plants doubled compared with the available K in the soil without biochar. In any case, the use of numerical modeling was proven helpful for a quick assessment of biochar performance in soil, by avoiding time-consuming and laborious experimental set-ups. Validation of the models by experimental data will further establish the proposed mechanisms.

【 授权许可】

Unknown