Soil Science - Science topic

Autoclaving and heat sterilization can cause physical and chemical changes to the soil that may impact the output of your research questions depending on your focus. Of course each method has its limitations and the selection of the best for your use case will need to take into account all the dimensions of your experimental work. For impacts on physical structure it is worth reading this article :Li, H., Liu, L., Li, C. et al. Efficiency of Different Soil Sterilization Approaches and Their Effects on Soil Particle Size Distribution. J Soil Sci Plant Nutr 23, 3979–3990 (2023). https://doi.org/10.1007/s42729-023-01315-2 There is also an interesting comparison paper "Sterilize Methods Comparison for Soils" | International Journal of Methodology (aijr.org)

In previous experimentations for large volumes I have used gamma irradiation but again this doesnt come without issues.

The geoform or relief of the soil, associated with the taxonomic nature of the soil (tropical and temperate soils) and its climatic conditions (tropical in the case of Paraguay) influence the availability of nutrients and these influence the microbiological quality and quantity of the soil. An interesting area of ​​research would be to relate these conditions to the sustainability of agricultural systems, seeking management associations that allow strengthening ecosystem services, as management tools that compensate actions to combat neutral land degradation.

I believe the next decade will be a transformative era for soil health. Microbial innovations, precision agriculture, and regenerative practices like cover cropping and reduced tillage will be pivotal. A particular focus on soil carbon sequestration through regenerative agriculture is crucial. By building soil organic matter, we can enhance fertility, improve water retention, and mitigate climate change. This holistic approach, blending technology with nature-based solutions, will be essential for creating sustainable and resilient agricultural systems.

Sodium hexametaphosphate (SHMP) is commonly used as a dispersing agent in soil texture analysis to help break down soil aggregates into their individual particles (sand, silt, and clay). This process is crucial for accurate soil texture measurement. The question of whether sodium polyphosphate (SPP) can be used as a substitute for SHMP in this process requires consideration of their chemical properties and effectiveness as dispersing agents.

Chemical Properties and Function

Sodium Hexametaphosphate (SHMP):

Sodium Polyphosphate (SPP):

Feasibility of Using Sodium Polyphosphate

Using SPP as a substitute for SHMP in soil texture analysis is feasible, but its effectiveness and the required concentration need to be evaluated. Here are the steps to consider:

Potential Issues and Considerations

Conclusion

Sodium polyphosphate can potentially be used as a substitute for sodium hexametaphosphate in soil texture analysis, but its effectiveness and the appropriate concentration must be determined through preliminary testing. Generally, a concentration of 5-10 grams per liter is a good starting point. It is important to compare the results of SPP and SHMP to ensure that the substitution does not compromise the accuracy of the soil texture measurement.

Janson offers a good recommendation. Let me add a couple of other thoughts. There are several states of soil moisture content to consider. The extremes are bone dry (oven dry) and saturation. Using an oven to dry a soil sample then taking the weight is a good step. You also need the weight of the soil in a saturated state. This should be easy to to. Remember, Field Capacity is the amount of water held in the soil after gravity drainage has stopped. The sample should be allowed to drain without the influence of evaporation. When the water stops draining, take the weight. This will get you the target weight. I do not know the nature of the test, but just a reminder, plant roots need air and water. When soil moisture is kept at field capacity, roots will remain shallow to the the air the plant needs. Allow soil moisture to be depleted to 50% +/- of Plant Available Water, which is the amount of water held in the soil from Wilt Point to Field Capacity.

Biochar's long-term effectiveness in soils is influenced by its original material and how it was made, along with the type of soil, climate, and how it's used in land management. Different combinations of these factors can affect how well biochar improves soil health, stores carbon, and supports plant growth over time.

The different carbon fractions of the soil amended with fresh residues showed significantly higher mineralized rates than with same quantity of compost because the higher amounts of humic substances and fulvic and humic acids that serves to support plant life.

Sudden or unexpected changes in the Soil moisture or water contents can be caused by a lot of factors majority of which are environmental conditions or changes-

1: The amount of moisture or water in the environment to a large extent will determine the amount of water that will be added to it or be removed from it, what I mean is that if the environment is saturated with moisture as a result of rainfall or precipitation then their will be sudden increase in the amount of water in the soil and when the environment is dry, their will be a corresponding increase in the amount of water that will be required by the environment through evaporation hence, the amount of water in the soil will reduce.

2: Changes in the environmental temperature to a larger extent determines the amount of water that will be lost from the soil per time.

Other factors of significant impact are - the drainage situation of the soil in question due to the ratio of large to small pore spaces presence in the soil; Soil type- you don’t expect the same amount of water retention in a clayey soil and that of a typical sandy soil; the nature of the ground water is also a factor etc

The leaching process duration can be estimated using the leaching requirement formula:

t = H/K

where:

- T is the leaching time,

- H is the leaching requirement (difference between initial and desired salt content), and

- K is the hydraulic conductivity.

Arkaprava Roy If you are in initial phase of your work, you may skip the Peterson and Corey method and go for Hedley fractionation / or its modified latest version scheme who is now being widely used .You may also estimate organic P in your soil samples as the samples contain high amount of organic matter.The following reference may be consulted for organic P estimation.There is a new method for organic P estimation based on NMR but facilities may a limitation for you.

Critical evaluation of methods for determination of total organic phosphorus in tropical soils . Soil Sci.Soc.Am.J.54:1261-1266(1990)

Paul Milham sir, I am extremely glad to receive your reply!

Thanks for reminding me that soil P 'pools' can't be superimposed over soil P 'fractions'. Unfortunately, I'm posted at a very young research institute in India and don't have access to either FTIR or NMR.

I am still curious about what might be the dominant composition of the residual fraction of P because it contributes to almost 40% of the total P content in my paddy soil. The studied soil is clayey Inceptisol with a pH of 7.84, high in amorphous Fe and Al, rich in organic (1.72%) and inorganic C (1.39%), geogenically arsenic-contaminated, and has been regularly fertilized with NPK for the last four decades. The abundance of different P fractions that I found in my study follows: Residual-P>Ca-P>Fe-P>Al-P>Occluded-P>Saloid-P.

If we are using selective extractants to solubilize the elements (Fe, Al, Ca) majorly responsible for binding P to the soil, and if P is never an integral component of resistant aluminosilicate minerals, then where should this high amount of residual P be coming from when our soil is digested with HF? Is it coming from the P:

1. strongly associated with recalcitrant organic matter? However, the soil underwent 17 hours of shaking with 0.1 N NaOH for dissolving Fe-P and Occluded P, and NaOH should dissolve a considerable part of organic matter too.

2. structurally associated with or strongly adsorbed on well-crystalline Ca-, Fe-, or Al-compounds that our extractants are unable to dissolve?

When the probable mineral saturation states were studied in GWB software, it appeared that the discrete P-bearing minerals that could precipitate in our soil are Hydroxyapatite, Whitlockite, MnHPO4 and Strengite. Do these discrete minerals have some contribution to make in the residual pool? Or, do they get dissolved by the selective extractants that we are using?

3. so strongly occluded within Fe and Al oxyhydroxides or CaCO3 that 0.1 N NaOH has failed to solubilize?

4. associated with some other forms?

Until I get access to the relevant instruments to analytically address my doubts, I need the help of your profound expertise in soil chemistry in the form of theoretical insight.

Best regards,

Roy

Anand M Osuri Adam D. Gebauer Elizabeth P. Gordon Interested if any pub resulted from this, or if you'd be willing to share a method?! Thanks!

Assessing soil multifunctionality involves evaluating the capacity of soil to perform various ecosystem functions simultaneously. These functions may include nutrient cycling, water retention, carbon sequestration, habitat support, and more. Soil multifunctionality assessments are essential for understanding the overall health and sustainability of ecosystems and can inform land management and conservation efforts.

Here's a general framework for assessing soil multifunctionality:

Assessing soil multifunctionality is a multidisciplinary endeavor that often requires collaboration among soil scientists, ecologists, geographers, and land managers. It should be tailored to the specific context and objectives of the study, and it should contribute to the sustainable management of ecosystems and natural resources.

Harrison, this is a question of fundamental importance, not just for agricultural education, but education at large. To be more specific, it would be necessary to see the curriculum and courses that you already have for ag science education, and then look at the logical place for soil science to be inserted. On the other hand, most universities, and all land grant schools here in America, have soil science(s) as separate yet related courses in their schools of agriculture. There are also several "short courses" or lesson-based approaches which do not require an independent course.

Yes

contact to Dr. Sangram Kale

+91 8275327763

A number of variables can affect how polycoated urea reacts in soils with differing textural properties under various agroclimatic conditions. Here are some broad ideas to keep in mind:

1. Agro-climatic Conditions: Agro-climatic conditions encompass factors like temperature, rainfall, humidity, and seasonal variations. These conditions can affect the rate of urea release from polycoated coatings and subsequent availability to plants. Higher temperatures can accelerate the release of urea, while excessive rainfall or humidity can increase the chances of urea leaching or denitrification.

2. Soil Texture: Texturally divergent soils, such as sandy, loamy, or clayey soils, have different physical and chemical properties that can influence the behavior of polycoated urea. For instance, sandy soils have low water and nutrient retention capacity, which may affect the release and availability of urea to plants. Clayey soils, on the other hand, have higher water and nutrient holding capacity, which can affect urea release differently.

3. Soil pH and Microbial Activity: Soil pH affects the conversion of urea to ammonium and subsequently to nitrate through microbial processes. Different soil pH levels can impact the efficiency of the polycoated urea and its response in terms of nutrient availability. Microbial activity in the soil also plays a role in urea hydrolysis and nutrient release.

4. Coating Properties: The specific characteristics of the polycoated urea, such as coating thickness, solubility, and release pattern, will influence its response in different soils. Coatings with thicker layers or slower-release patterns might provide a more controlled release of urea, reducing nutrient losses and optimizing plant uptake.

5. Crop Type and Nutrient Demand: The type of crop being cultivated and its nutrient requirements can influence the response of polycoated urea. Some crops may have higher nitrogen demands during specific growth stages, and the controlled release provided by polycoated urea can align better with their nutrient requirements.

It is significant to note that depending on the particular soil and climate circumstances, polycoated urea performance can change. To establish the best use and performance of polycoated urea in various locations, specialized research, field tests, and professional guidance taking into account the unique agro-climatic and soil features of the region are required.

It can be done with the Walkley and Black method in which soil organic matter is digested with the known volume of chromate in presence of sulphuric acid and then titrating it against the FAS - Ferrous Ammonium Sulphate and then doing the necessary calculation gives you the amount of organic carbon present in the soil multiplying which by 1.724 gives you the amount of soil organic matter.

Poppycock; soil science, to the extent that it still is an independent department anywhere, is nearly always linked to a school of agriculture. The argument that "soil science as a discipline was rather narrowly defined in the 1980s as mostly including soil pedology and soil physics" fails to understand soil science. The SSSA was established in 1936 with six sections: physics, chemistry, microbiology, fertility, morphology, and technology. Soil science evolved to be adopted as a focus of research by other that traditional soils scientists, often building on concepts developed in agriculture. The link did never disappear, but soil science became the basis of more than just agricultural work. What is correct is that the pure soil science departments morphed and were re-labelled, as agricultural research fell out of fashion for a while. It is also correct that soil science is insufficiently recognized as a self-standing science by many nations' funding societies (merged into earth sciences or geography). So no, the argument of the authors is severely flawed. As to the 1900 to be the date when soils science became a science, debatable, depending of how we classify the work of Liebig, Dokuchaev and many others.

rainfall, vegetation, soil microbes, sunshine

R-is good!

@ Sudip, you may use microbes for nitrogen-fixation, phosphorus solubilization and mobilization, suppression of pests and pathogens, improvement of plant stress, and decomposition that leads to soil aggregation. Microbial enzymes can be used for nano-nutrient production and enhancing polysaccharide production in the soil resulted more soil aggregation, moisture retention and soil carbon build up .

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

Yes, the difference between soil pH measured in water and CaCl2 can be used to indicate soil buffer capacity, as it reflects the ability of soil to resist changes in pH when acid or base is added. However, it is important to note that this method only provides an estimate of soil buffer capacity and is not a definitive measure.

The smaller the difference between soil pH measured in water and CaCl2, the smaller the buffer capacity of the soil. This is because soils with a lower buffer capacity are less able to resist changes in pH caused by acid or base inputs.

There are several studies that have used this method to estimate soil buffer capacity, and it has been shown to be a useful indicator in many cases. However, it is important to note that other factors, such as soil texture, organic matter content, and nutrient status, can also influence soil buffer capacity and should be considered when interpreting results.

References:

Why should an award be named after a (long-forgotten) scientist after all?

This is just a leftover 19th century heroism, with the idea that a single person can move the whole scientific community and should be honored for it by putting his/her name on an award.

In my opinion, the awardee should be in the spotlight.

Best suiting for this would be an award title that highlights the criteria/achievement for which the awardee was awarded, like "Posterpreise 2022" or "outstanding young soil scientist of 2023"

This would also avoid a lot of future trouble, when the new "name" appears to be not so great after all.

There are a few ways to access free journals or obtain fee waivers for low-income countries:

Hi dear researchers, thank you for pointing out the important issue of tree planting in carbon sequestration. According to my knowledge and my job at betterSoil company, non-governmental companies are doing projects of tree planting. For example, one of the principles at betterSoil company is agroforestry. BetterSoil itself could plant 650 trees since 2019 in Iran and is going to have more plans in this case in the framework of agroforestry. You may visit the website of betterSoil initiative to get more information: www.bettersoil.info

You may also find more information about its project of tree planting under:

Best, Elaheh

Thank You so much sir for your kind suggestion but now I'm working on Mustard Aphid and soil fertility management@Ahmad Al Khraisat

P2O5 (actually P4O10) is a drying agent and not a fertiliser. P2O5 exists neither in soil, nor in fertiliser bags. It's high time we abandoned the use of P2O5 in academic writing.

Lambers H and Barrow N J (2020) P2O5, K2O, CaO, MgO, and basic cations: pervasive use of references to molecules that do not exist in soil. Plant Soil 452, 1-4. 10.1007/s11104-020-04593-2.

Eszter Gulacsi Peter Donkor Craig Carlton Dremann J. C. Tarafdar

I hope that you would find interesting regarding our newly published research article. Please have a read and provide your recommendations:

Soil is not a group of mineral elements accumulated on top of each other, but rather it is a vital medium that contains in addition to the mineral elements a variety of plant and animal organisms that play a major role in soil formation and development. They play an important role in the biochemical reactions that take place in the soil and that result in the transformation of Organic matter into humus and the preparation of nitrogenous materials necessary to feed plants. These reactions are activated when the natural conditions (heat, ventilation, humidity) are suitable for the activity of these organisms.

Aerobic culture of methanogenic archaea without an external source of hydrogen - PubMed (nih.gov)

You are right in that soils vary in their capacity to accumulate soil organic matter.

The amount of capacity can be a function of clay content and the amount of calcium.

When clay and organic matter become complexed through the agency of cationic bridging the decay of soil organic is greatly reduced and this favors soil organic matter accumulation.

In a very sandy soil the adding of silt and clay will result in better soil organc matter conservation and increase.

In the acid soils the liming will improve the ability of soil to retain can conserve soil organic matter.

Soil calcium is need for the earth worm activity with are prime buider so soil organic matters.

A well wormed soil has excretion of calcium precipitates.Vermicompost is characterized by high content of calcium and phosphorus and serves as an excellent organic starter amendment giving both a complete nutrient resource but also humic materials which stimulate germination and seedling response particularly root development.

Thank you!

You can check Google. Regards

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).

I am totally agree with @ J.C. Tarafdar Sir. Apparently soil Respiration and dehydrogenase activity measures the microbial activity in soil. For soil Respiration we can go for either alkali trap that has been discussed or we can go for rapid techniques by comprehensive analysis of soil health by Cornell University.

I would suggest you try books by Nyle C. Brady.

I found these links, hope they are useful:

Sandip Kumar Gupta

No, the use of inorganic fertilizer can not increase / cannot contribute the organic matter in the soil.

Yes, it can be present. As worms tunnel, they consume almost everything in their path, including microscopic plastic pollution.

Earthworms can be significant transport agents of microplastics in soils, incorporating this material into the soil, likely via casts, burrows, egestion, and adherence to the earthworm exterior (Rillig et al., 2017). However, in common sense, vermicomposting is the method of making compost (humus-like material known as vermin-compost) from biodegradable waste by using earthworms.

Good replay

Strongly Negative correlation

Dear Ashar Ahmad

You can measure the exchangeable cations using Ammonium Molebdate solution under spectroscopy.

Also check please the following useful link: https://www.agdaily.com/insights/net-zero-mean-farmers-ranchers/

By adding surfactants surface tension of water molecule is lowers due to decrement in cohesive forces acting between water molecule. Due to this loss of water from plant canopy surface reduces which turns reduces in transpiration rate.

Also check please the following useful RG link:

Muthucumaran Sugirtharan i cam eacross the water chemistry link and felt like sharing with you where it is clearly explained how the OLR and the COD is linked and how it can be calculated as well so in other words I can explain like - Two things must be known to determine the organic loading on the trickling filter: the pounds of BOD or COD applied to the filter media each day and the volume of the filter media in 1000 cubic feet. The organic loading does not include the recirculated flow's BOD and COD contributions.

Link of the water chemistry document for your reference

As you know bulk density is mass of solid divided by total volume of soil. So in Sandy soil total volume is high as volume of solid + volume of pores are there. So as a result bulk density of sandy soils reduces.

Oxidation and microbial proliferation leads to SOM loss. So as long as it is safe from oxidation and microbes there will be no loss of SOM. But still if tillage is done in soil and exposure of surface soil to sunlight is happen then it will take very less time for SOM to loss.

I would say soil profile. Bcz it gives a comprehensive idea regarding horizons, and various elements present only by visual effects.

Undoubtedly Urea

I do agree with Paul Milham.

Below you can find the link to two recent published papers:

The first one is recommending the best performing dosage of biochar in co-composting in improving the quality of compost and reducing nitrogen loss. Here it is emphasized on the point that composting can be used to transform the layer manure, nitrogen rich solid wastes generate in poultry breeding and agricultural production, into a environmental-friendly and more stable fertilizer product.

The second one is recommending the best conservation agriculture wheat-rice production strategy accelerating soil carbon pools and hydrolytic enzymatic activities and also the best idea for its overall adaptation to appropriately carry out the ecosystem functions.

Thomas Fungenzi Tough question but i dont think that the carbonates can be found in the acidic soils as it is found or in fact present in the alkaline soils

Extraction of trace elements soluble in aqua regia was used as a decomposition method in accordance with ISO 11466: 1995 E.

1 g sample was weighted accurately in a reaction vessel; 0.5 ml of tri-distilled water was added to obtain a slurry, followed by 9 ml of HCl (12 mol l-1) and 3 ml nitric acid (15.8 mol l-1) .Then 10 ml of 0.5 mol l-1 was added to the absorption vessel which was connected to the reflux condensor. Both apparatus were placed on the top of the reaction vessel. The samples were allowed to stand for 16 h at room temperature in order to reduce the produced during the subsequent heating cycle. They were heated under reflux until boiling for 2 h and allowed to cool slowly at room temperature. The contents and the following rinses of the absorption vessel were passed through the condenser into the reaction vessel. The content of the reaction vessel was transferred quantitatively to a 50 ml graduated flask and filled up to the mark with nitric acid (0.5 mol l-1). After the undissolved material has settled, the supernatant solution was subjected to analysis by ICP-AES.

A blank sample containing the acids used for digestion was prepared in the same way.

In general wet digestions excluding hydrofluoric acid do not attack the silicate matrix. Hence, the separation of the silicate matrix as an insoluble residue from the soluble elements lead to both lowering the dissolved solid concentration in solution and the detection limits for analytes, respectively.In addition, the procedure is carried out in closed system and losses of volatile elements can be eliminated.

With kind regards, N Daskalova

Hello, Adil Mihoub

Maybe because of Christmas festivals, you can contact the journal office.

Crop models can assist in preseason and in-season management decisions on cultural practices, fertilization, irrigation, and pesticide use. Crop models can assist policy makers by predicting soil erosion, leaching of agrichemicals, effects of climatic change, and large-area yield forecasts.

https://www.crops.org/publications/aj/pdfs/88/5/AJ0880050704

Seed coating is the practice of covering seeds with external materials to improve handling, protection, and, to a lesser extent, germination enhancement and plant establishment.Here, we analyse the science and industry of seed coating and its contribution to seed establishment and plant performance.

The priming process regulates the seed's temperature and moisture content, bringing the seed closer to the point of germination. The process involves advancing the seed to an equal stage of the germination process, to enable fast and uniform emergence when planted.

Seed priming is an old experimental tactic employed by farmers since eras to enhance germination activities in crop plants. Biopriming of seeds with microorganisms not only improve the growth and development of plants by regulating several biochemical and physiological processes but also impart stress tolerance and resistance mechanisms in plants.

Types of priming:

1. Hydropriming

2. Osmopriming

3. Halopriming

4. Matrixpriming

5. Nanopriming

6. Biopriming

I would also be glad to come in with climate change, farming systems and soil science. Thanks.

1. Proportional mixing of good quality water (If available) with saline water.

2. Addition of FYM and compost can reduce the salt effect by producing organic acids on decomposition.

3. Use of salt tolerant variety's (Best option among all)

4. Application of Gypsum in saline water can reduce the Na to Ca ratio and SAR and facilitates good infiltration.

5. Mulching with locally available material can reduce the evaporation by that salt accumulation can be reduced.

This is a good question.

This is a good question.

That is a good question.

That is a good question.

Tomato blossion end rot increases under ammonium fertilization it is related to boron calcium deficiency.

Boron can be deficient in many global soil situations and the boron content optimized by address acid soil aluminum toxicity.

Yes! returning the residues to the soils is very vital to improve the levels of soil organic matter since inherent OM is influenced by C addition and decomposition rate. When I came to your question incorporating plant residues into the soils can aggravate the decomposition process and thus, C in the form of carbon dioxide will escape to the surrounding environment therefore surface retention is more suitable to minimize GHG emission.

Dear Anna,

The link below leads you to a project emerging a promising solution in mitigating the accumulation of plastics in the environment. You may also follow the works of the project coordinator.

I hope this helps you to persuade your scientific goal.

Best, Elaheh

Clay loam soil. Theoretically, for maximum compaction there should be an equal proportion of sand, silt and clay fraction, i.e. 33 per cent each. But in nature, it hardly happens. Therefore, try to have proportion within 10 per cent deviation among these fractions to have maximum compaction. Yes type of clay particularly, swelling type is also the factor which determine maximum compaction at given moisture content. Proctor moisture shall be used for achieving highest compaction. May contact further on vkphogat@gmail.com. thanks

Hi! do you have literature about the identification of leaves maturity in every branch?

Yesterday, I attented in a seminer on the use of vermicompost and cowdung. The results showed that vermicompost was better both in rice field and vegetable crops.

I'd recommend the answer of Sal Mangiafico

Thank you, Dr. Frank T. Edelmann

To be frank, I believe the answer is relative to this issue. Only textbooks that I am familiar with or have come across can be recommended. However, you are the only one who knows what study areas you are passionate about.

Rather than relying on a single textbook, I believe you can find knowledge by searching online databases, books, journals, and other serial blocks using keywords from your research objectives.

Thanks Dr- Abhishek Raj for your response.

check this out.

Depending on your specific application, I would recommend mixing your own standard soil using kaolite and/or activated carbon as a base. I would especially recommend kaolite (chemical composition Al2Si2O5(OH)4) as it is widely commercially available available either as 'kaolin clay' or 'china clay'. Both kaolite and activated carbon is used in many industrial processes and can be purchased in various sample sizes. Activated carbon is often used I use kaolin clay and activated carbon in standardized soil samples for this reason, and that the particle size range is very well defined in many commercial products.

Below I have included some useful links if you want to investigate further.