Nowadays, with rising level of soil degradation and soil pollution, we need to concentrate more on soil health, sustainability and thereby food security. In this regard, I hereby send you a recently published paper about using agroforestry method for the protection of a natural peatland. This paper is maybe helpful to find the modern concepts of soil quality assessment in it.
I have read alot of papers dealing with soil quality index to compare soil quality. Such statsitical analysis allows for selection of both total data set (TDS) and more important ly minimum data set (mds) for easier data dissimination.
The link should be a good read for implementation of SQI
Dear Dr Maftuna Karimboeva . The indicators are solid particles and pores.This including : topsoil depth, bulk density, porosity, aggregate stability, texture, crusting, and compaction. See the link: https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_053149.pdf
That depends. But most important will be to assess SOC/SOM which is kind of drivers for your biogeochemical cycle and soil quality (quality and health are kind of different though people use it simultaneously to represent one another), then to know, your soil structure, you can use aggregate stability, bulk density, to know your infiltration efficiency you can measure hydraulic conductivity, or you can measure volumetric water content both at wilting point and field capacity. Then to know, how active your soil ecosystem is you can measure some of the labile C and N fractions, like active carbon or pox-C, water-extractable organic carbon, then ACE protein, water-extractable organic nitrogen, which can be used to calculate different decomposition rates or you can use to calculate the quality index. Then most importantly you should measure your pH, CEC (as anionic, cationic exchange capacity determines a lot of stabilization and destabilization parameters). Then you can measure nitrate and ammonium in different depths also to determine, how good your soil is in providing plant-available N and the rate of nitrification (which can be correlated to different nitrifying bacteria, anammox, etc.) and you can calculate some nitrous oxide gas also to complete the N -cycle. Then to further expand, you can go for a PLFA study that will use biomarkers (like long-chain or short-chain fatty acids profile, especially from microbial cell membrane) to identify microbial composition. then if you specifically want to know, which genus or groups are there, you can go for either culture-dependent or independent method (more preferable nowadays, considering the sequencing rate have drop-down and a lot of high throughput analysis methods are there) using short read hypervariable regions of 16S rRNA or you can use complete shot gun sequencing of your soil profile, that way, you can identify your group of bacteria plus the biogeochemical cycle, especially using sequence to predict enzyme for each step of C and Biogeochemical cycle or of your interest. There are few other indexes and methods but based on your hypothesis and theories, you can stick to one or more parameters.
As far as soil quality/health is concerned, the most important parameters includes soil organic carbon and soil pH along with important soil quality physical parameters. Also microbial species and mineral content and type of soil are important.
Soil quality is very broader term may constitute soil fertility,productivity as well as interconnected channels through many physical chemical and biological properties of the soil...There are many more parameters of soil quality which may be interrelated with physical and chemical and biological characteristics of the soil, governing soil functions in direct or in indirect manners.. organic carbon fractions,total soil microbial count, adequate aeration so as to optimise oxygen demand by the flora and fauna are of qualitative traits of a soil... pH range of soil may also contribute significant difference as pH may influence type and extent of microorganisms depending on the survival within definite pH ranges like fungi, bacteria and actinomycetes proliferate well in acid, neutral and basic pH, respectively..Supply of nutrients in adequate and suitable proportion so as to optimise healthy growth and development of crop, C.E.C of the soil govern quality...soil texture also depicts quality of the soil by influencing retentive power of water and nutrients to sustain soil ecology and fertility...C: N ratio, enzymatic activity related with transformation of essential nutrients for plant uptake, better functioning of soil micro and macro flora fauna for maintaining an equilibrium between the soil, crop, environment and microorganism itself are some other attributes which can be considered for defining soil quality...
Chemical properties of soil can be tested with different soil analyzing methods. The five tested soil tests for fertizer and lime recommendations had strong correlation, but the determination of nutrient deficiencies needs local calibration of deficiency limits, because soils and other farming conditions are different. https://doi.org/10.1111/sum.12738
CEC is an important measure for classifying soils and planning nutrient additions.
Seldom farmers get the info of CEC in his soils, because it´s not included in routine soil tests offered to farmers. But CEC is possible to estimate of soil sample results without adding costs. https://doi.org/10.1002/saj2.20340