Aggregation and fractal dimension of aggregates formed in sand dunes stabilized by PistachioPAM and PistachioPVAc mulches

作者：Saiedi N; Besalatpour A A^*; Shirani H; Dehaji P Abbaszadeh; Esfandiarpour I; Faramarzi M

来源：European Journal of Soil Science, 2017, 68(5): 783-791.

DOI：10.1111/ejss.12458

Wind erosion is a serious environmental problem that has received increased attention by attracting the interest of academics, policy makers and the public. In this study, the effects of combined mulches (denoted as PistachioPAM and PistachioPVAc, used for stabilizing the sand dunes in the Davaran plain in southeastern Iran) on aggregate formation and stability indices were investigated by the theory of fractal geometry. In addition, the temporal changes in soil organic carbon (SOC) content and microbial respiration rate (MRR) in the soils treated with the mulches were compared with the control samples during a 5-month experiment. The results showed significant (P<0.01) increases in the SOC content and MRR following the application (1.5lm(-2)) of PistachioPVAc and PistachioPAM mulches. The rate of release of CO2 was measured in the soils treated with the mulches studied. The largest rate of CO2 release from the three samples taken in weeks 2, 5 and 19 from the beginning of the experiment was about 23.0 mu g-CO2 day(-1)g(-1) soil. The smallest and largest mean weight diameters (MWD) of the aggregates formed were observed in the control (0.06mm) and the PistachioPVAc (1.38mm) treatments, respectively. The use of mulches had significant (P<0.01) effects on the fractal dimension of aggregates. The more stable and coarser aggregates formed in the presence of PistachioPVAc had the smallest fractal dimension. The largest negative correlation between the properties investigated and the fractal dimension was for SOC and MWD. Therefore, it appears that the theory of fractal dimensions is useful for explaining the temporal variation of aggregate stability in soil stabilized by combined mulches.
Highlights
Effects of combined mulches on aggregate formation were investigated with fractal geometry theory (FGT).
The more stable and coarser aggregates formed in the presence of PistachioPVA mulch had the smallest fractal dimension.
Mulches increased soil organic carbon and microbial respiration significantly (P<0.01).
The FGT might be useful for explaining the temporal variation in aggregate stability of stabilized sand dunes.

• 出版日期2017-9