Abstract. Organic materials (e.g., furfural residue) are generally believed to improve the physical and chemical properties of saline soils with low fertility. Recently, biochar has
been received more attention as a possible measure to improve the carbon balance and improve soil quality in some
degraded soils. However, little is known about their different
amelioration of a sandy saline soil. In this study, 56 d incubation experiment was conducted to evaluate the influence of
furfural and its biochar on the properties of saline soil. The
results showed that both furfural and biochar greatly reduced
pH, increased soil organic carbon (SOC) content and cation
exchange capacity (CEC), and enhanced the available phosphorus (P) in the soil. Furfural is more efficient than biochar
in reducing pH: 5 % furfural lowered the soil pH by 0.5–0.8
(soil pH: 8.3–8.6), while 5 % biochar decreased by 0.25–0.4
due to the loss of acidity in pyrolysis process. With respect to
available P, furfural addition at a rate of 5 % increased available P content by 4–6 times in comparison to 2–5 times with
biochar application. In reducing soil exchangeable sodium
percentage (ESP), biochar is slightly superior to furfural because soil ESP reduced by 51 % and 43 % with 5% furfural
and 5 % biochar at the end of incubation. In addition, no
significant differences were observed between furfural and
biochar about their capacity to retain N, P in leaching solution and to increase CEC in soil. These facts may be caused
by the relatively short incubation time. In general, furfural
and biochar exhibited a different effect depending on the
property: furfural was more effective in decreasing pH and
increasing available P, whereas biochar played a more important role in increasing SOC and reducing ESP of saline
soil.