Response of Fractal Analysis to Soil Quality Succession in Long-Term Compound Soil Improvement of Mu Us Sandy Land, China

Haiou Zhang,Zhen Guo,Haipeng Nan,Jiancang Xie,Jichang Han

doi:10.1155/2020/5463107

Abstract

The degraded aeolian sandy soil in China’s Mu Us Sandy Land requires amendment before it can be suitable for maize or other agricultural production. The addition of material from the local “soft” bedrock can create a new compound soil whose particle composition and structural stability are key issues for sustainable soil development in the region. We used field data from 2010 to 2018 to study the variations in fractal characteristics of compound soil particles at soft rock to sand volume ratios of 1 : 1, 1 : 2, and 1 : 5, along with changes in soil organic matter. Over the study period, all three compound soils showed gradual increases in clay and silt content with corresponding decreasing sand content. The fractal dimension (FD) of particles at ratio 1 : 2 increased by 8.8%, higher than those at 1 : 1 (8.6%) and 1 : 5 (7.7%). The organic matter content (OMC) of particles at ratio 1 : 2 reached a maximum (6.24 ± 0.30 g/kg), an increase of 12 times over the original value. The FD and OMC of particles at ratios 1 : 1 and 1 : 5 were less stable but showed overall increase. The 1 : 2 ratio compound soil was most suitable for maize growth as its clear increase in silt and clay content most improved the texture and OMC of the original sandy soil. Such research has important theoretical and practical significance for understanding the evolutionary mechanism and sustainable use of the compound soil in agriculture within the Mu Us Sandy Land.

Highlights

Soil particle composition is an important indicator used for monitoring and evaluating desertification in northern China as it has a vital impact on the biological, physical, and chemical properties of the soil [1, 2], which directly affect the abundance and deficiency of soil nutrients, as well as changes in organic matter content [3]
The clay content of the compound soil with ratio 1 : 2 increased steadily, reaching 2.68 times its initial value, while that of the 1 : 1 and 1 : 5 compound soils were more variable but showed an overall increase of 2.38 and 2.45 times the initial value, respectively. e silt content of the 1 : 1, 1 : 2, and 1 : 5 ratio compound soils increased by 2.4 times, 1.52 times, and 1.64 times, respectively, while the sand content decreased by 51.4%, 16.1%, and 24.4%, respectively
Changes in fractal dimension (FD) can represent the development of new compound soil created through the mixture of sandy soil and soft rock in the study area

Summary

Introduction

Soil particle composition is an important indicator used for monitoring and evaluating desertification in northern China as it has a vital impact on the biological, physical, and chemical properties of the soil [1, 2], which directly affect the abundance and deficiency of soil nutrients, as well as changes in organic matter content [3]. Soil is a porous medium composed of multisized particles with irregular structure, with certain fractal characteristics. Ai et al [7] used a fractal method to characterize soil particle size distribution and determined the fractal characteristics of synthetic soil for cut-slope revegetation in the purple soil area of China. Liao et al [8] and de Bartolo et al [9] applied fractal analysis to detect the spatiotemporal variability of soil moisture content for different land use activities

Methods

Results

Conclusion