Photograph via snooOG

A subreddit for all things soil, or soil science related.

The Soil reddit

Soil - a natural body consisting of layers that are primarily composed of minerals which differ from their parent materials in their texture, structure, consistency, color, chemical, biological and other characteristics.

Wikipedia: soil


  • Please keep all discussion to soil or agriculture based topics

  • Please try and post scientifically sound articles (i.e. that include sources) but all soil posts are welcome

  • Feel free to ask general, or homework related questions. We are a small sub, so an answer may take time, but we will try and get to it!

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The Nature and Properties of Soil

Soil Fertility and Fertilizers

An Illustrated Guide to Soil Taxonomy PDF

The Canadian System of Soil Taxonomy PDF

USDA Handbook on Erosion Control PDF

Soil Sampling and Methods of Analysis PDF Canadian Society of Soil Science

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Help with homework

The question in this photo is :is there evidence of the natural water table….. I don’t know where to start

02:28 UTC


what is pore water pressure at the base of layer 1 (fast i have exam )

04:15 UTC


Help me with this problem

solve this problem based on 9.3 figure How low should the water table depress so that the effective stress at C is 100kN/m2

14:51 UTC


Excellent Example of a Polyculture Orchard with Alley Cropping - Datça Peninsula - Southwest Türkiye

09:52 UTC


does anyone know source book these examples ?

03:00 UTC


Kaolinite tattoo - help?

Hi there! I’m looking to get a tattoo of kaolinite (what we potters would associate with porcelain.) I don’t just want to get the chemical formula in times new Roman (which would be Al2O3·2SiO2·2H2O because ceramicists think in oxides) - so could anyone let me know if this physical structure is accurate? Terrified to get something inked that’s incorrect!

Thank you in advance for your help :)



03:47 UTC


Chicken grit in soil question.

00:06 UTC


Inducing Drought in a Pot Experiment

Hi, everyone! Biology student here. Our group is currently preparing for our undergraduate research. Our topic is about enhancing the drought tolerance of spinach thru seed biopriming. We are going to use two bacterias, B.subtilis and P.fluorescens.

We initially proposed that we will induce drought thru lowering the field capacity of soil (idk if field capacity is the right term even if its just a pot ecperiment). Now, we could not find a high calibrated soil moisture sensor. Also, we are in a tight budget. High calibrated ones are too expensive for us to buy. We could not also conduct gravimetric method.

Now, we are thinking of another way of inducing drought in our set up. We are resorting to do the interval watering. Basically, we are going to have three set ups. Well watered, semi watered, and rarely/low watered. Then, test the soil moisture each set up every week.

Will interval watering will do?

Thank you so much!

16:57 UTC


Amending soil with clay?

While setting up my garden, I had some top soil delivered that turned out to be of rather poor quality. This is especially prominent in areas where I sowed grass, where (after 2 years) it is very compacted and doesn't seem to allow any plant growth in some spots.

I sent samples to a lab and it turns out to be ~5% clay/silt and ~1.5% organic matter. A home-made mason jar experiment seems to confirm that it's basically all sand.

Now I don't want to replace the entire top soil. I don't need a perfect lawn and I'm fine with some green weeds . I have plenty of beds with shrubs and trees that are doing fine with a thick layer of woodchip mulch.

I plan to add a layer of fine compost onto it, which is often recommended. However, I'm considering mixing that compost with fine ground clay, about 2kg of clay per m2, as I read in some papers that clay amendments help with water retention and general soil structure.

Is adding clay mixed with compost onto this lawn and maybe raking it in a bit a good idea?



Thanks for all the hints. I see most people are at least skeptical about adding clay.
Being me, though, I won't just leave it at that. I'll set up experimental patches: one with just compost added, another with compost mixed with clay and of course plenty of control with no intervention. I'll try to upload results here in a year if I don't forget ;)

14:00 UTC


How long is sterilized soil good for?

Sterilized some soil in my oven for some tricho seeds about 3 weeks ago. I have about half of a gallon ziplock baggie full of it now that I’d like to use but don’t want to risk it with my seeds before knowing it’s safe. Do you think the soil is still sterile? It has not been exposed to air since I first used it and there is a fair amount of humidity in there. Baggie has always been in room temp or a bit colder but never hot or in the sun. Of course I can sterilize a new batch but would like to use this soil if I can. Any response is appreciated!

16:52 UTC


can you challenge a land evaluation site assessment score (LESA). Grandparents in escrow on their 20 acre home/ranch to developer on farmland that hasn’t really ever been profitable for farming and as of now only brings in $10k a year. . .

03:07 UTC


Advice needed after sewer line replaced in front yard.

We got rid of our lawn and had a nice native garden going. Then sewer line problems hit.

They dug a deep hole, but when they went to refill it, I could see they were going to end up putting clay from 8' down on top, so I told them not to fill it all the way.

I dumped a bunch of top soil in. It keeps settling. But nothing is growing either.

Is there a "right" way to recondition this spot?

22:07 UTC


Moisture Meters

I'm trying to understand how to use a basic moisture meter (the ~$10 kind from any big box) for the best results. Do these meters measure the moisture at the tip of the meter, or is it an average for the part of the probe in the ground?

In my situation, I'm attempting to optimize lawn watering to have good moisture at 6" depth. Would I insert the probe 6" to get that number, or would 12" be better since it would then be an average of the full 12" depth (and 6" should be about in the middle)?

Thanks for any help on this.

19:13 UTC


Experience Working as a Soil Conservation Tech at the NRCS (+advice for a new grad)

I'm graduating soon with a degree in Environmental Science with enough soil classes to qualify to work as a Soil Conservationist. I'm considering applying for Soil Conservation Tech positions and was wondering if anyone had any thoughts or experiences they'd want share.

Do/did you like it? What was something you didn't expect about the position? What's a typical day/week like? How long did you stay with the agency, and what positions did you have with them?

I'm also wondering if anyone would like to give any insight into some post grad plans I'm considering. For context I go to school in California and I'm from the Bay.

  1. Move home, work at a consulting firm, save money, then apply to NRCS positions having both more experience and money to relocate if needed (which seems likely with the agency)

  2. Try to work for the NRCS directly out of college (which would involve moving), save money but not as much, try to work my way up the pay scale

I know none of it is guaranteed, but if I had the opportunity to do both, which would you recommend I go for? The appeal with 1 is I'll be back home with my family and making more so I can save more. The appeal with 2 is I'll be doing what I think I ultimately want to do right away (or I found out it's not for me right away and move on) and won't have to take a pay cut coming from Bay Area consulting salary to anywhere else Federal pay.

I'm open to expanding on some things I mentioned!

15:25 UTC


Review of Soil Mechanics

11:37 UTC


is the soil in my backyard redeemable?

Hi, like the title says, I'm trying to fix my soil but don't know if it's even achievable. I have adding soil and grass but the grass didn't survive and the soil disappeared.

I have tried poking 3 inch holes all around the terrain and I have tried throwing powdered lime and mixing it.

anything else I can do to fix this?

23:13 UTC


Analyze my soil

Wichita, Kansas. Is it silt and clay? What else can I tell from this? Thank you

19:49 UTC


Any tips/advice on "creating" soil to save money at the garden center?

I'm planneing to dig out a couple more plots in the garden, and I'm curious if theres any good "recipes" for good vegetable garden soil. I know where I can get an endless supply of coffee grounds, and grass clippings as well as food scraps are always readily available. Is there anything else that would be necessary for a good, healthy "homemade" soil? Feel free to answer simply, or teach me as much detail as you'd like!

23:34 UTC


What kind of soil is this? Will someone please delineate down to the series please?

01:53 UTC


How to I determine effective depth for agricultural drainage?

I'm in the process of planting an orchard on land that has for a very long time been used as cow pasture. There are certain areas that are pretty wet and need to be drained before apples will grow there. Some of this is due to compaction from livestock, but they're also areas where the slope of the terrain flattens out enough to collect water. I've read that drainage tile isn't an option when the "clay layer" is higher than the depth the tile would need to be (3 ft.). If the clay layer starts less than 3 feet down, drainage tile isn't an option How do I determine the height of the clay layer? The soil contains a lot of clay naturally, and in a swampy stream area nearby, I hit gravelly clay at about 20 inches down. Is this the impervious layer my text is talking about?

19:55 UTC


Soil instrument recommendation

Can anyone recommend a quality instrument for measuring soil pH and temperature. The one in the picture is of course as good as it costs (cheap). It's important that it is easy portable.

14:35 UTC


Oil Spill on Property

Hellllllo! Looking at buying a lovely 1920s home in the Seattle area. The house includes an inspection report and an additional 100 pages with thorough documentation about an oil tank spill that happened on the property in 2015. Essentially, the oil tank's lid was left off and when rain entered the tank 60 gallons of oil were displaced 450 square feet across the property. The oil tank was removed and a natural gas furnace was purchased. Over 60,000$ of cleanup was required after the spill. A state environmental firm (PLIA) then tested the soil in 8 locations. Soils were field screened from the surface to a depth of 17 feel below the ground surface. There is a very detailed report regarding the soil impacts and continued clean up was not recommended. (Tho, the report is so detailed and very difficult to understand as someone who doesn't work in geology).

The listing agent said the only lasting impact would be if we wanted to build a DUAD we'd have to put down an extra lining (she compared it to a pool liner) between the soil and the foundation. We don't have any plans to expand on the property.

Does anyone have experience with a situation like this? Is this a red flag for the property or have any long term health impacts?


1 Comment
19:25 UTC


Soil test

What are your comments on a soil sample having following properties :

  • Moisture Content(%) - 26.68%
  • Sand(%) - 64.4%
  • Fines(%) - 35.6%
  • Silt(%) - 33.6%
  • Clay(%) - 2%
  • Liquid Limit (%) - 28.44%
  • Plastic Limit (%) - 25.2%
  • Plasticity Index (%) - 3.24%.
16:35 UTC


Soil stratification?

Am I ID'ing the soil stratification in this jar correctly? I can't tell if that bottom layer is actually sand or more silt. This is only after about 24 hours so anticipating there's probably a little more clay that hasn't settled on the top.

When taking the soil sample, I broke up most of the smaller dirt/clay chunks. Should I have done that or just left them as is?

1 Comment
23:41 UTC

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