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Soils with Biological Problems
Published in Manorama K.C. Thampatti, Problem Soils, 2023
Soil organic matter plays a major role in improving soil structure. The active and some of the resistant soil organic components, together with microorganisms especially fungi are involved in binding soil particles into larger aggregates and thereby improves soil structure, aeration, water infiltration and resistance to erosion and crusting.
Desertification Vulnerability Assessment
Published in Ajai, Rimjhim Bhatnagar, Desertification and Land Degradation, 2022
As regards to desertification and land degradation, one very important parameter to consider is soil structure. Management practices, e.g. use of heavy machinery, and any other practices which change soil's organic matter content, affect the soil structure and hence its stability. Soil structure is how individual soil particles (sand, silt and clay) are arranged into soil aggregates (peds). Many factors affect soil structure such as soil texture, organic matter content, compaction, moisture levels and management practices. When the soil structure is single grained i.e. when sand particles do not form aggregates or massive or when aggregation is not present, such soils are ‘structureless'.
Application of biochar in amelioration of saline-alkali soil
Published in Binoy K. Saikia, Advances in Applied Chemistry and Industrial Catalysis, 2022
Jing Zhang, Yan Jiao, Wenzhu Yang
Microorganisms are important participants in soil biochemistry. Their distribution and activity in soil are closely related to the formation of soil structure and the transformation of nutrients and play an important role in the formation of soil fertility. But in saline-alkali soil, the activity of microorganisms will be inhibited, which will affect the growth of crops.
Exploring challenges in safe water availability and accessibility in preventing COVID-19 in refugee settlements
Published in Water International, 2020
Nazifa Rafa, Sayed Mohammad Nazim Uddin, Chad Staddon
Soil structure determines the degree of infiltration, and thus the availability of water below and above ground. Sandy soil tends to allow more infiltration of water compared to clayey soil due to its increased diameter and larger pore space. Permeable rocks can lead to less surface water but lead to the formation of aquifers, which are sources of clean water. Many regions do not possess aquifers and may thus have to turn to surface water or other alternatives, which are often unsafe to use and thus expensive to purify. For example, two of the areas Rohingya refugee camps have been built in Cox’s Bazar are Teknaf and Ukhiya. While Ukhiya enjoys the benefit of several groundwater resources, Teknaf has none due to the presence of hard impermeable rocks (UNHCR, AUW & Oxfam, 2020). As a result, water scarcity is far more marked in the Rohingya refugee camps in Teknaf due to the absence of groundwater sources. The concern is whether the existing water sources in Bangladesh will be able to supply water to both its growing national and growing refugee populations to prevent COVID-19 infections.
Enhancing the interface friction between glass fiber-reinforced polymer sheets and sandy soils through sand coating
Published in Geomechanics and Geoengineering, 2020
Ahmad Almallah, Pedram Sadeghian, Hany El Naggar
The behaviour of interface friction between substructure materials and soils plays a significant role in many soil-structure systems, including friction pile foundations. The direct shear test is an effective means of obtaining strength parameters of the interface between soils and interfacing structures. Potyondy (1961) studied the friction behaviour of the interface between some conventional construction materials (i.e., concrete, steel, and wood) and soil. He found that the primary factors affecting the soil-structure interaction are surface roughness, moisture content, soil composition, and the magnitude of normal loading. To examine the pile-clay interface, Taha (2010) studied the shear behaviour of the interface between marine clay and concrete and steel piles. By using an automated direct shear machine, he found that the interface strength increased with increasing relative roughness of the material, resulting in an increased over consolidation ratio (OCR) and clay density. In contrast, he found that the interface shear strength decreased as the degree of soil saturation increased. Rouaiguia (2010) investigated the residual shear strength of a clay-structure interface by using a modified direct shear test. He found that surface roughness was the primary controlling parameter. Paikowsky et al. (1995) found that grain shape and surface roughness are key parameters which control the interface shear strength.
Measurement and modelling of organic matter’s altering effect on dielectric behavior of soil in the region of 200 MHz to 14 GHz
Published in Journal of Microwave Power and Electromagnetic Energy, 2023
Prachi Palta, Prabhdeep Kaur, K. S. Mann
It was observed that OM present in soil affects water retention properties of soil. The results showed that as OM in soil increased from 0.78% to 17.28% of total soil mass, field capacity (FC) of soil increased from 5.55 to 34.69 (% total volume) as shown in Figure 1. The increase in FC is attributed to the reason that presence of OM in soil improves soil structure and increase surface area for incoming water molecules (Chiou et al. 1990). As soil structure refines, the binding forces between soil and water molecules increase which results in the water holding capacity of the soil. Hence, the FC of soil increases with the OM of soil. Similar results have been observed earlier by researchers like BD Hudson (1994), Huntington (2006), Minasny and McBratney (2018), etc.