Historical geomorphology and pedology of the Gandak Megafan, Middle Gangetic Plains, India
The Gandak megafan of eastern Uttar Pradesh and northwestern Bihar lies in the Middle Gangetic Plains. The Gandak River has shifted about 80 km to the east due to tilting in the last 5000 years. This has created a soil chronoassociation similar to the chronosequences found on some flights of river terraces. This chronoassociation has five members, QGD1-5. They are distinguished on the basis of profile development, clay mineralogy and calcium carbonate content. Chlorite transforms to vermiculite on a large scale from QGD1 to QGD3 and decreases drastically in member QGD4. Kaolinite and interstratified kaolinite-smectite are abundant in the older members of the chronoassociation. The youngest soils (QGD1:? < 500 b.p.) are found on the floodplains of the major rivers. QGD2 soils, like those of the Young Gandak Plain, date from? > 500 b.p., while QGD3 soils, like those on the Older Gandak Plain and Old Rapti Plains date back to 2500 b.p. QGD4 soils, like those on the Oldest Gandak Plain, are dated as? 5000 years b.p., whilst the oldest QGD5 soils, as on the Old Ghaghra Plain and Ganga-Ghaghra Interfluve, date back to 10000 b.p. These soils, which include pedogenic calcite and a? saline epipedon, indicate a dry climatic spell during the period 9000-11000 b.p. Faults developed on the megafan are not related to the basement structures. [1]
Pedology and digital soil mapping (DSM)
Pedology focuses on understanding soil genesis in the field and includes soil classification and mapping. Digital soil mapping (DSM) has evolved from traditional soil classification and mapping to the creation and population of spatial soil information systems by using field and laboratory observations coupled with environmental covariates. Pedological knowledge of soil distribution and processes can be useful for digital soil mapping. Conversely, digital soil mapping can bring new insights to pedogenesis, detailed information on vertical and lateral soil variation, and can generate research questions that were not considered in traditional pedology. This review highlights the relevance and synergy of pedology in soil spatial prediction through the expansion of pedological knowledge. We also discuss how DSM can support further advances in pedology through improved representation of spatial soil information. Some major findings of this review are as follows: (a) soil classes can be mapped accurately using DSM, (b) the occurrence and thickness of soil horizons, whole soil profiles and soil parent material can be predicted successfully with DSM techniques, (c) DSM can provide valuable information on pedogenic processes (e.g. addition, removal, transformation and translocation), (d) pedological knowledge can be incorporated into DSM, but DSM can also lead to the discovery of knowledge, and (e) there is the potential to use process-based soil–landscape evolution modelling in DSM. Based on these findings, the combination of data-driven and knowledge-based methods promotes even greater interactions between pedology and DSM. [2]
Historical development of key concepts in pedology
As a subdiscipline of soil science, pedology consists of an accepted body of laws and theories that cover a range of related ideas and concepts. We have traced the history of these concepts as they pertain to the definition of the soil; soil horizons, profiles, and pedons; soil-forming factors; pedogenic processes; soil classification; soil geography and mapping, and soil–landscape relationships. The presented concepts have proven to be useful in our careers and are offered here to generate discussion in the pedology community. Because of space limitations, we have not attempted to critique these concepts. The concepts identified here are useful not only for understanding the development of pedology, but also for identifying future areas of research and providing a frame of reference from which pedologists can evaluate potential scientific contributions to a rapidly changing world. [3]
Hybrid Approach for Electrophoresis Pattern of Seed Storage Proteins and Soil Study (Pedology); a Study on Intra Specific Diversity of Stachys inflata Benth
Aims: For determination of levels and types of intraspecific diversity in the identified groups, electrophoresis studies and soil studies were employed.
Study Design: This study has designed base on accumulation of species and laboratory works.
Place and Duration of Study: Department of biology, plant laboratory of BASU University in Hamedan and the duration was between September 2009 and September 2010.
Methodology: Stachys, a genus of the Lamiaceae family, with more than 300 species is wildly distributed throughout the world. DSS method (Determination of Special Station) is the method of choice for this study which has established itself as an efficient method to study intraspecific diversity. 13 special stations for Stachys inflata were selected where 72 plant species are distinguished as associated species of these special stations. Floristic-ecologic data analyzed by Anaphyto software using F.C.A (Factorielle Correspondance Analysis) method.
Results: Comparison of the results led to determination of 9 groups for this species which reveals the existence of intraspecific diversity in Stachys inflata. The electrophoretic profiles of seed storage proteins are in accordance with floristic- ecologic and soil study groupings. Results obtained from the analysis of electrophoresis of seed storage proteins by MVSP (Multi Variante Statistical Package) and NTSYS software were also in accordance with floristic-ecological groupings. The number of bands and their density varied in this species, indicating their intraspecific diversity in the populations of Stachys inflata Benth.
Conclusion: Therefore, in this species, the grouping by floristic marker was confirmed by electrophoresis as well as soil data. As a result by using D.S.S method, the number of groups and their members were completely identical and utilizing ecological data such as soil caused to detect intraspecific diversity in this species. [4]
Hydrostructural Pedology, New Scientific Discipline Allowing for Physical Modelling of ‘Green Water’ Dynamics in the Soil-Plant-Atmosphere System
Using a new paradigm of soil characterization and modeling in agro environmental sciences, named hydrostructural pedology, we were able to show that the “green water” concept of agronomists corresponds exactly to the pedostructural water concept which was physically defined in this paradigm. The water in the pedostructure of soils is composed of two types of water, named micro and macro, nested one in the other. They are differentiated by their chemical potential related to their position in the pedostructure: inside primary aggregates or outside of them in the interpedal space. A fundamental physics of the pedostructural water could be developed within this new paradigm. Finally, the soil medium can now be considered as the location in which the free water (named also blue water), coming from surface (rainfall, irrigation, etc.) and going down by gravity through the macro pore space of the soil, is partially absorbed by the pedostructure, and becomes then the ‘green water’ of the soil. Soil green water is, in fact, the soil water reserve available to plant roots and subsequently transpired by the plants into the canopy. The soil-water model Kamel®, built according to this new paradigm, is the only model able to physically simulate the opposite dynamic cycles of these two kinds of water (blue and green) within the soil-plant-atmosphere system, their exchanges and equilibrium states according to time, at each depth of the pedon. Important implications about strategy of soil-water characterization, mapping and modeling are given for sustainable development and management of agricultural zones. [5]
Reference
[1] Mohindra, R., Parkash, B. and Prasad, J., 1992. Historical geomorphology and pedology of the Gandak megafan, Middle Gangetic Plains, India. Earth surface processes and landforms, 17(7), pp.643-662.
[2] Ma, Y., Minasny, B., Malone, B.P. and Mcbratney, A.B., 2019. Pedology and digital soil mapping (DSM). European Journal of Soil Science, 70(2), pp.216-235.
[3] Bockheim, J.G., Gennadiyev, A.N., Hammer, R.D. and Tandarich, J.P., 2005. Historical development of key concepts in pedology. Geoderma, 124(1-2), pp.23-36.
[4] Jahandideh, E. and Rad, A.C., 2016. Hybrid Approach for Electrophoresis Pattern of Seed Storage Proteins and Soil Study (Pedology); a Study on Intra Specific Diversity of Stachys inflata Benth. Journal of Advances in Biology & Biotechnology, pp.1-11.
[5] Braudeau, E., Boukcim, H., Assi, A.T. and Mohtar, R.H., 2018. Hydrostructural pedology, new scientific discipline allowing for physical modelling of ‘Green Water’dynamics in the soil-plant-atmosphere system. Journal of Agriculture and Ecology Research International, pp.1-8.
