Comparison of various sustainable amendments on soil cracking in semi-arid regions

Abstract

Soil desiccation is an important process that happens mainly in semi-arid regions especially in Central Asia. Soil desiccation leads to higher loss of moisture at shallower depths and also deeper penetration of water, which ultimately reduces water availability and hence impacts the growth of plants for the application of agriculture and green infrastructures. Therefore, minimizing soil desiccation will help maintain higher water availability for plants for agricultural productivity and green infrastructure in Central Asian Region. In literature, various amendments such as natural fibers, cementation, lime, vegetation and biochar have been used to suppress cracking of soil. There is rarely any study that analyses and compares mechanism of crack suppression among the above-mentioned methods. The objective of this study is to explore various sustainable methods of minimizing soil desiccation and compare their mechanisms. Further, the aim is to analyse the feasibility of these methods by revealing their advantages and disadvantages. In order to achieve this objective, 1-D columns were prepared with control soil and amended soil (with fibers, vegetation and biochar). The review also provides insights into their mechanism of suppression of soil cracking by proposing a new factor (i.e., normalized CIF). Based on the proposed factor, the efficiency of biochar and fiber amendments are higher than that of vegetation. Vegetation may or may not have positive impact on cracking of soil depending on their shoot length. Among various amendments, wood biochar (10% content) and coir fiber (at 0.75 % content) seems to have highest efficiency in reducing cracking in soil. Overall, the study aims to develop preliminary guidelines suppressing soil desiccation in semi-arid regions such as Central Asia.