Pedology - Science topic

Pedology is the study of soils in their natural environment. Pedology, in its broad sense includes soil survey, mapping, geomorphology, soil micromorphology, and soil and clay mineralogy with special reference to soil formation. Soil structure is an essential property of soil quality because it impacts the storage of carbon, inorganic phosphorus (Pi) availability, plant growth, and nutrient absorption. Soil aggregates, especially water-stable aggregate is a well-recognized part and an important index to evaluate soil structure . Fertilization has been proved to affect the formation of soil aggregates. Biofertilizers are now an effective way to increase crop yield and soil health in organic farming. The use of minerals that contain fertilizer nutrients in their native state is a very promising approach to reducing emissions associated with the processing chemical industries. Soil minerals serve as both sources and sinks of essential plant nutrients. Alteration in the pedological features by the plant community causes significant modification in the environment.

Thank you Qasim Qayyum Kashif, that's very interesting. I appreciate the time you're spending to help with this.

Tushar Kumar Take a look:

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The soil map of any country could be downloaded from "FAO Map catalog - digital soil map of the world in ESRI shape file formats" but not properly overlap even I adjust the the type projection. what is wrong please?

It depends on what can be seen on the respective images. This in turn depends on the location the image shows and the time the image was taken. The scorpan factors can therefore be s (bare soil), o (vegetation) or p (parent paterial).

Tushar Kumar

I suggest reading these papers:

1. https://www.diva-portal.org/smash/get/diva2:1515573/FULLTEXT01.pdf

2.

HBD and I wish you more years!

rockware software

The use of terracing agrotechnology in the foothills prevents irrigation erosion.

By studying the TIME FACTOR of soil genesis. There are factors that accelerate and those that retard soil profile development. Investigation of resistant and non-resistant parent materials can also give insights on past pedogenic activities.

On the field, simply fill method you can use for determination of soil textures and most critically by international pipette method in the laboratory.

Soil surface area is an important property of soil which governs surface bound processes like adsorption- desorption, synthesis of new mineral phases etc.. However, processes like water movement , heat flow and gaseous exchange are controlled by relative proportion of different size soil separates. Therefore, in my view soil surface area alone may not help in characterizing soils for their physical and ion exchange properties.

Temperature, rainfall got definite relationship with vegetation and soil organic matter and soil organic carbon. These are long established phenomenon.

Teaching students how to learn - It is based on the principle that learners must be taught how to search for and discover knowledge rather than a teacher spoonfeeding them with the knowledge. Thus, educators globally advocate the implementation of learner-centred approaches rather than teacher-centred approaches. It is as it were, arming the students with knowledge on how to fish rather than giving them fish.

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Read this article and check the bibliography. It can be useful for you

Hi. 1. If the property changes over time, the classification must be carried out again. 2. If there is a new version of the soil taxonomy, it is necessary to carry out the classification with that version since it could change. (Before doing so, you can review the substantial changes that this new version brings and decide if it is necessary to do so)

I have had a significant amount of experience with prairie soils in the north central US (mostly mollisols). In my evaluation of cropland soils, grassland soils, and wetland soils, I have found the C:N ratios almost always at about 11:1 +/- 1 which is at the 10:1 value. This is assuming that the soils are in equilibrium with their management and environment. This can vary, usually when additional plant/animal biomass is added but due to the microbial equilibrium reestablishing shortly after the biomass is added, returns to near the equilibrium level.

An interesting sidelight of evaluating soil C:N ratios is their usefulness in evaluating environmental pollution or contamination. Contamination from hydrocarbons will widen the C:N ratio due to the excess C while fertilizer contamination will narrow the C:N ratio due to excess N. the rebound from each of these types of contamination take some time to rebound and evaluating C:N on a periodic basis can be used to evaluate effectiveness of remediation.

Please have a look at enclosed PDF..

The concept of mull, moder, mor is applicable for forest covers. But for agriculture crops humus is also equally valued by farmers and gardeners because it provides nutrients essential for plant growth, increases soil water absorption, and improves soil workability. Above ground organic matter comprises plant residues and animal residues; below ground organic matter consists of living soil fauna and microflora, partially decomposed plant and animal residues, and humic substances. The C:N ratio is also used to indicate the type of material and ease of decomposition; hard woody materials with a high C:N ratio being more resilient than soft leafy materials with a low C:N ratio. Most of our productive agricultural soils have between 3 and 6% organic matter. 

I suggest you can develop your local PEDO TRANSFER FUNCTION FROM AVAILABLE SOIL DATA ESPECIALLY TEXTURE, OM

I think the SPT N Values show wide variation in Clayey soils with a slight change in moisture content . We performed SPT Tests for a clay formation in dry season (June 2015) and got SPT N values in the range of 20-25

for the same site (formation ) the SPT N values were recorded in the Range of 02-05 only in December 2015 (It was after a rain spell)

I think this link is useful, 

It is better to avoid PSA; it does not provide weight percentage data.

I do not know if there are studies using SEM in these areas but it has been increasingly used in ecological studies. R programming language is free and there are many packages developed for SEM, such as lavaan.

The attached document was developed in the Riverland region of South Australia, and reflects relatively sandy topsoils over carbonate rich subsoils.  The recommendations reflect the impact of these subsoils on both drainage and root penetration by different crops.  Whilst perhaps not directly applicable to your conditions, I hope it provides some useful guidance.

Thanks a lot

Dear José:

Answer to your question is yes. Which is the next question ?.  Embraces from Colombia.

Hello Bikram,

Good luck with your ventures. Your incorporation of traditional knowledge technology has a lot of merit and I wish you well.

Kind Regards,

John

Hello,

concerning Ultisol and Oxisol (Acrisols and Ferralsols in WRB), as commonly they are "old" soil resulting from intense leaching of base cations and eluviation of clay  along long period of landscape stabibility, you cannot generalize their origin. They have common actual "features" (low CEC, argilic or ferralic horizon) but concerning their genesis they can have polylithologic origin resulting of weathering of different parent material. They seems to be linked to humid climate according to soil scientist, nevertheless you should also take into account more geodynamic factors allowing intense wetahering like lithospheric upwarping (see Works of Robert Wyns).

There are various approaches to downscale SMOS data (or any of the passive sensors, for that matter). It depends on the resolution you want to achieve. For example, Dumedah et al (2014) showed that you could just use the SMOS L2 Tb data without much of a problem at its ~15km resolution, that should be transferable to soil moisture, too.

There are also physical and empirical downscaling algorithms, such as those of Merlin et al. and Piles et al. Both produce 1km soil moisture products using various forms of MODIS data to calculate the spatial variability within a L3 pixel (note: not L2, but that should not matter), making use of the link between thermal emissions and soil moisture.

Check out the references:

Dumedah, G., Walker, J. P., and Rüdiger, C., 2014. Can SMOS Data be Used Directly on the 15km Discrete Global Grid?, IEEE Transaction on Geoscience and Remote Sensing, 52(5): 2538-2544

O. Merlin, M. J. Escorihuela, M. A. Mayoral, O. Hagolle, A. Al Bitar, and Y. Kerr, “Self-calibrated evaporation-based disaggregation of SMOS soil moisture: An evaluation study at 3km and 100m resolution in Catalunya, Spain,” Remote Sens. Environ., vol. 130, pp. 25–38

Piles, M., Sanchez, N., Vall-llossera, M., Camps, A., Martínez-Fernández, J., Martínez, J., & González-Gambau, V. (2014). A dowscaling approach for SMOS land observations: long-term evaluation of high resolution soil moisture maps over the Iberian Peninsula. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 7, 3845-3857

I second the use of remote sensing variables (surface reflectance) already mentioned. The choice of remote sensing platform would at least partially depend on the size of your study area. Also, you should consider your research question before you choose environmental covariates. Landsat is a very common data source and you can calculate a number of important reflectance indices that represent soil, geology, and vegetation.

I strongly support Colby's suggestion about using multi-temporal RS. This is a nice way to get around some management differences (e.g., fence lines) that would otherwise complicate soil predictions and variations in vegetation dynamics can also help with soil prediction. I'm happy to send more detailed examples if you like. Some Landsat 7 indices we've used include: 3/1, 7/5, calcareous sediment index, gypsic index, NDVI, etc.

Some folks have also been using gamma-ray measurements for soil predictions.

Isn't the answer in what your needs are? Pedological soil maps are useful for inferring co-varying soil properties (CECsoil varies with clay content, soil structure, plasticity index, etc.) of that soil pedogenetic soil type e.g. Vertic soils.

On the other hand all soils have a clay content it that is what is important the spatial variation in all soil types would be more useful but less useful for extrapolation.

Ok, it is an engenering task, it is out of my expertise field. Cheers. Carlos

Hi Marcos, where in MT are you working ? We do have measured some SRWC  curves in some regions of MT.

Moreover have a look on these works 

BARROS, A. H. ; de Jong van Lier, Quirijn ; Maia, A.H.N. ; SCARPARE, F. V. . Pedotransfer functions to estimate water retention parameters of soils in northeastern Brazil. Revista Brasileira de Ciência do Solo (Impresso), v. 37, p. 379-391, 2013.

BARROS, A. H. ; de Jong van Lier, Q. . Pedotransfer functions for Brazilian soils. In: Teixeira, W.G.; Ceddia, M.B.; Ottoni, M.V.; Donnagema, G.K.. (Org.). Application of Soil Physics in Environmental Analyses. 1ed.Berlin: Springer International, 2014, v. , p. 1-.

Good luck

Wenceslau

Dear Daniel,

What do you meanby " Age of the soil? " It is too fuzzy, are you speaking of the last pedogenese? The age of the parent material? Because soils are polygenetic most of the time.

kind regards

Dear Beloula,

In my point of view, you should also determine van Genuchten parameters which shows the soil water tension curve. These parameters are essential for almost all models which applied in soil research.

We frequently hand-drilled up to more than 10 m in depth (the max. we reached was 13m) in Amazonian deep soils. At each withdrawall, you have to disassemble the auger string in segments of max. 5m to prevent it from twisting. Be careful: do not drop a short segment in a deep hole! If this happens, make a loop with a rope at the end of a drill rod and go fishing, twisting the loop when it is around the segment to retrieve.

A "soilscape" represents a sequence of contiguous lands within a geomorphological entity. There are usually interactions between the properties of the lands and their soils. The indices that explain these interactions should be sought case by case. Topographic conditions, drainage and soil depth generally provide the most relevant indices. Other important indicators are related to the chemical soil fertility such as pH, but they do not appear as such on the soil maps. However, the most "fertile" soils are generally cultivated while the less fertile are assigned to pasture and forest.

Thank you for your answer.

Yes, Y do. Clay cutans are escarse and thin in E horizon but one of them is thick.

Yes, I have pictures that I will include in a paper. If you want I would sent you a picture.

My feeling is that they correspond to a local movement of colloids in the upper part of a strong Bsst horizon (clay: 62%). There are not evidences of litological discontinuities between E and Bsst horizons. Thak you again.

In a simple way , we can consider a "Pedon" as a 3-D structure (minimum 1 m2 surface up to 10 m2) that contain all the properties of the studied soil.

The soil profile is defined as a vertical section of the soil from the ground surface downwards to where the soil meets the underlying rock (USDA Soil Taxonomy). In this way, a soil profile could be one of the vertical face of a pedon.

Soil Horizons, are the different layers (in an horizontal disposition) of a soil proilfe (with different properties and characteristics as color, texture, MO content, etc) that let us to characterize and describe a soil profile in order to classify it

Dear Evangelos,

relating FC and AWC may pose some difficulty as you also have to include a dry limit (wilting point, WP), all affected by multiple parameters. A first idea of how to approach PTFs may be found here: http://www.pollaccowater.org/hydrology/Universal_pedotransfer_function_project_files/PedotransferFunctionFcPWP.pdf (quite detailed description). I suggest you also check some publications by Rawls et al. Good luck :)

Here's that paper on stream power based on combining DEM-based slope values with the CEH Flood Estimation Handbook approach I mentioned above for estimating the 2-year flood at 50-70m intervals down complete river systems.