Characterization of soil amendment potential of 18 different biochar types produced by slow pyrolysis

Authors : Hikmet GÜNAL, Ömer BAYRAM, Elif GÜNAL, Halil ERDEM

Pages : 329-339

Doi:10.18393/ejss.599760

View : 12 | Download : 6

Publication Date : 2019-10-01

Article Type : Research Paper

Abstract :Feedstock type is the most dominant factor influencing the physical characteristics and chemical composition of biochar. The main purpose of this study was to characterize and compare some of the physical and chemical properties of biochars produced by slow pyrolysis of 18 feedstocks, which are locally available agricultural residues. Moreover, elucidating the potential agronomic benefits of these biochars was the other objective of the study. Biochars were produced at 500 o C in an ingeniously developed reactor. The biochars were characterized for specific surface area insert ignore into journalissuearticles values(SSA);, field capacity insert ignore into journalissuearticles values(FC);, wilting point insert ignore into journalissuearticles values(WP);, plant available water content insert ignore into journalissuearticles values(AW);, pH, electrical conductivity insert ignore into journalissuearticles values(EC);, cation exchange capacity insert ignore into journalissuearticles values(CEC);, total carbon insert ignore into journalissuearticles values(C); and nitrogen insert ignore into journalissuearticles values(N);, plant available phosphorus insert ignore into journalissuearticles values(P); and potassium insert ignore into journalissuearticles values(K); concentrations. Considerable variation of characteristics among biochars indicates the dominant impact of feedstock type on physical properties and chemical composition of biochars. Total C contents were highly variable with values up to 91.9% for pine sawdust. Phosphorus and K in feedstocks were concentrated in the biochars and were two to four times higher in the biochars. The CEC of biochars varied from 79.5 cmol kg -1 insert ignore into journalissuearticles values(pepper residues); to 5.77 cmol kg -1 insert ignore into journalissuearticles values(poplar sawdust);. The CEC and SSA had a significant negative correlation insert ignore into journalissuearticles values(P<0.01, r= -0.70); that probably be attributed to the loss of functional groups during pyrolysis. The results revealed that depending on the feedstock, some biochars have potential to serve as nutrient sources as well as an additive to improve soil quality.
Keywords : Agricultural residues, feedstock type, biochar, physical and chemical properties, soil quality