More than three decades have passed since the concept of soil quality was first put forth. It is made up of the physical, chemical, and biological characteristics of the soil [41,42]. Although soil quality (SQ) cannot be measured directly in the field or a lab due to its complexity, it can be inferred using a variety of soil indicators. As documented in Kumar and Kalambukattu [43], Figure 2 depicts different soil quality indicators.According to Andrews and Carroll [44] and Wienhold et al. [45], indicators of soil quality are characteristics of the soil that are responsive to changes brought about by management and represent ecosystem services and functions. The physical, chemical, and biological characteristics of agricultural soils must be evaluated to determine their quality. In the past, different soil indicators such as pH, nutrients that measure soil fertility [46], texture, electrical conductivity (EC), cation exchange capacity (CEC), and soil organic matter (SOM) [47,48] have been analyzed to evaluate the quality of the soil. Management strategies and soil health evaluations are based on these soil characteristics. It is challenging to determine how much soil can sustain crop development, filter pollutants, and even store carbon without knowledge of these characteristics [47,49,50,51]. Consequently, farmers are better equipped to assess the condition of their soil and decide how best to manage it for crop growth [52], establishing a connection between crop yields and soil quality [53].Seven factors were chosen to represent soil’s biological, chemical, and physical characteristics [54]. The soil texture and saturation percentage (SP) were chosen as the physical soil quality criteria. SOM was chosen as the biological quality parameter. Soil reaction (pH), EC, phosphorus (P), potassium (K), and calcium carbonate (CaCO3) were chosen as the chemical quality measures. Numerous scholars have proposed these indicators as a means of assessing soil productivity, nutrient availability, soil porosity, root development, soil structure, and soil aggregation stability [55,56,57,58,59]. The most important elements in determining SQI are SOM, clay, EC, and CEC, as demonstrated by Bedolla-Rivera et al. [60]. The term “soil organic matter” refers to the entire amount of all substances containing organic carbon in the soil, generated from plants or animals in varying phases of decomposition and breakdown [61]. An important measure of soil quality that plays a major role in providing ecosystem services like food production and carbon sequestration is the level of SOM. Manlay et al. [62] reported that SOM is a potent marker of land degradation and fertility, and it has a significant impact on many soil characteristics and biological cycles. According to Obriot et al. [63], using SOM instead of mineral fertilizers enhanced the condition of the soil. One of the key components in preserving the physical quality of the soil is SOM. Adding organic modifiers to the soil significantly increased the rice output [64]. The authors claimed that the stability and improvement of aggregates were to blame for this. Reducing agricultural methods and adding organic compounds together increase the physical condition of soil [65]. One of the most vital soil nutrients for the ecosystem is nitrogen (N), and a lack of it limits soil organic matter stability and production [66]. The weathering and breakdown of minerals in the parent material produces phosphorus (P), an important ingredient in SOM. Second only to nitrogen in terms of nutrient limitations on crop output, phosphorus is often the most problematic [67]. Fertilizer use, meteorological conditions, and land/crop management strategies can all have an impact on soil pH, which is a measure of the soil’s acidity and alkalinity and affects nutrient solubility and availability, SOM decomposition, and weathering of parent material and minerals [68]. Reduced levels of available macro-nutrients (N, P, K), SOM percentage, and CEC negatively impact soil quality [69]. CaCO3 has a positive effect on soil quality by enhancing water-holding capacity (WHC) and reducing hydraulic conductivity (HC) [70]. Soil quality is significantly influenced by soil texture. Coarse sands lead to deep soils with poor physical properties, such as high density, rapid infiltration rate, and low water retention [71]. Additionally, physical properties such as shallow depth and coarse texture disrupt soil particles and pores, impeding root growth and water infiltration during agricultural practices [69]. As a result, texture plays a crucial role in water and nutrient retention, aeration, and root growth, significantly contributing to soil quality [72,73,74]. The “master soil variable”, (pH) of the soil, has a profound effect on a range of biological, chemical, and physical properties of the soil. It greatly affects the activity of enzymes involved in the breakdown of organic molecules as well as biogeochemical processes [75]. While chemical and physical soil quality indicators are commonly utilized, soil biological indicators have demonstrated greater responsiveness owing to their swift reaction to alterations in the environment) and are hence considered superior indicators of soil quality [75].
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