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!

  • No advertising, or corporate promotions


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

Related Reddits:

And Check Out the Big List of Related Reddits


11,881 Subscribers


Have you ever used composting bag based advance jivamrut for improving soil?

I recently got to know about this. Just thought if anyone know or used this innovative anaerobic compost bag for soil and plant improvement?

09:38 UTC


Problems reforesting tropical saprolite badlands. Please help

Title pretty much says it all. I live in the tropics and work with forestry. We are using Acasia trees to reforest and they’re not native. I’ve noticed the approach is always conventional like just looking at npk and rainfall. I’m thinking since reading studies that the native microbes matter and when nonnative trees are planted to reforest it effects the area. I think we would have better results with native trees using native (to that specific are) microbes, bacteria, ferments, or amendments. One of the problems is the areas are very acidic and only get good rainfall half the year. To offset this we add lime, but I think lime takes to long and mostly effects the surface. I think adding gypsum would help and go deeper. I believe that disrupting the area with nonnative trees isn’t as productive as the microbiology specific to that area suffers. Long term a lot of these tree plantings are not super successful. I believe we need multiple soil tests throughout the year in one area before and after planting to know how to better amend the area. These areas are pretty much dead and the lack of focus on bringing back soil biology is a problem for the immediate and long term success. Please throw me all the ideas, insights or knowledge you have. This is a huge problem here in the pacific. It damages our drinking water, reefs, wildlife and actual landmass. Forgot to mention the soil type is saprolite and a lot of the soil here is clay type.

09:58 UTC


Need Help Fixing My Soil!

We moved into our property last year. We have been working on rejuvenating the property and have made some progress, but I'm having a hard time bringing life back to some areas.

Link to soil pictures and videos https://imgur.com/a/y5gngig

Any suggestions are appreciated!

22:08 UTC


Who here makes their own soil and whats your recipe?

I saw on a gardening thread how Miracle Gro is considered pretty poor. It made me wonder about all the times Ive simply used that in pots and beds. Now Im guessing Ill have to be a bit better with my shopping.

06:11 UTC


Antifreeze spilled into soil

I was cutting out a pipe of my pool heater and about a quart to half gallon of antifreeze spilled into the soil where it was located. I sprayed it with water and then tried to dig out as much as I could before covering with additional new soil and pavers.

I have a two yr old and a 6 month pregnant wife so I just want to make sure there is no danger to them. It is on the side of the yard that we don’t really go around

00:35 UTC


Saturation/Field Capacity field test

Hey All,

I’m wondering if any soil scientists out there know of an easy, quick field test for figuring out if a soil is saturated above the field capacity. I don’t need to know what the field capacity is (which is all I’ve been able to find researching this topic), I just need to know if the water in it will be able to drain out.

Background: I’m an environmental tech who drills monitoring wells all the time. I don’t have issues in the sandier soils, but the clayier stuff is really hard to interpret in the field. I’ve drilled wells into soils that looked pretty dry and had tons of water, and stuff that was sopping wet that had none. I believe this is because the field capacity is so much higher than sandier soil. If I interpret it incorrectly, there’s a good chance that my well will be dry.

00:38 UTC


Permafrost soil from Alaska

Ice wedge polygon core collected with sipre auger from arctic coastal plain Alaska.

05:56 UTC



21:22 UTC


Is espoma with myco-tone safe for growing food?

I want to grow some basil in an indoor pot and have espoma with myco-tone. Is this safe for growing food that I plan to eat?


04:42 UTC


Pile 'o clay - trash, or potential

I dug out a pond in the yard of a new house build, and after about a foot of garden topsoil that was added by the landscaper, I hit clay. Weirdly, there was about 6" of light brown coloured clay, and then a layer of darker almost black stained clay that smelled kind of gross and oily. Not sure if there was some weird chemical spill.

Anyway, I had to dig out a big pile of the stuff, and now it's sitting in my yard. I've been throwing puolled weeds, kitchen scraps and other organics at the pile, but wondering if that's even worth doing vs. just getting the entire pile dumped somewhere. Is there any chance this stuff can turn into good soil over time? I see posts about gypsum for certain types of clay, which I'm debating trying, as well as planting certain crops, but that seem to apply to trying to improve in-ground clay soil architecture, whereas this is just a big pile of clay. Curious as to people's thoughts.

05:58 UTC


How accurate is a jar test?

I've followed procedures I've read about on university sites to test different soils on my farm. Overall, I've been surprised with how little clay there is in the soils that act like clay. So as an experiment, I took some clay from a river bank that passed the pliability test where I could roll it into a coil around my finger without any cracks, and the jar test is still showing mostly silt. There is a lighter clay layer that settles out over 48 hours, but it's very thin compared to the layer beneath it. These are clays that I've molded and fired before.

Is it possible the clay is coagulating into larger chunks that are behaving like silt in the jar test? Is there any other way to determine clay content at home?

22:48 UTC


soil productivity/value - not corn & soybean based

are there indexes for soil value that are not based on corn and soybean production? like the commodity crop productivity index, but for literally any other crop?

context is researching other important values for soil health - for trees, vegetables, native pollinator plants, and livestock forage in Illinois - there's going to be a lot of variability of course and its a lot of information to cover, but even a nod in the right direction would be cool!

13:27 UTC


Soil focused start ups

I’m working on a project for a major miner focused on delivery of soils for the rehabilitation of old mine operations.

Are there any start ups or researchers that may not be on my radar that you think would be applicable for mass soil delivery in remote locations?

1 Comment
12:25 UTC


Heavy Clay Soil Help

I have one acre of heavy clay soil. Very poor drainage. You could probably make a vase out of it. The grass loves it and the trees do okay, but everything else struggles.

Last fall, I rototilled 2000 square feet and planted tillage radish. They stayed about two inches tall. I expected them to die in the winter, but they survived. Picked one in the spring and it had basically no root system.

Raised beds have helped in the meantime, but I want to plant about 800 linear feet of hedge, probably pyracantha. I would have to improve the soil first.

Already composting kitchen scraps, but I don’t think it’s enough. Any advice? Thinking of getting tons of wood chips and letting them rot for a few years. Maybe there is a faster way?

23:39 UTC


Compost or manure?

The soil at my veg patch is lacking in worms and life. Would green-waste compost or rotted horse manure be a better addition to help with this? Or something else?

Both would be a tonne bag bought from a local horticultural trader.

(Have used up all of our own home made compost already)


08:57 UTC


Best thing for the soil?

I recently dug up a bunch of plants and weeds from my front garden what’s the best thing I can buy on my soil if I’m going to turf it over?

19:53 UTC


Paver base in garden soil

15:08 UTC


NPK Soil sensors Question

I’m trying to apply run some experiments to see if I can boost the fertility of soil. I don’t have a lab so I want to run these experiments and then test for their nutrient content before and afterwards to see what changes and if it works. I’ve heard of NPK sensors but I’m relatively new in this area and unsure of if they work well. I’ve seen some old answers (a couple of years ago) that say they don’t work well, but I also see an abundance of npk sensors on the internet available for purchase right now? Has the technology been developed? Are these completely bogus?

I’m new in the space so I appreciate any alternative advice I receive towards testing the before and after results or any other methods there are to do something like this. Thank you so much.

12:22 UTC


Can someone tell me what soil is this

I have mixed a bit of shampoo and left it for 18 hours....mostly seems clay to me a bit of rock in bottom....can somebody confirm

10:03 UTC


Drying oven settings for drying soil samples

Hi all,

for my PhD I will collect soil samples which need to be dried in drying ovens before being ground and ultimately analysed for their nutrient composition. While drying, the samples will be weighted daily until the difference in weight between the current day and the day before is less than 5%. That completes the drying process. The soil samples consist only of litter-free hummus of rendzina type.

I have received the instructions that the samples need to be dried at 60°C under exhaust air.

We have two drying ovens, Memmert brand, I don't know the precise model. I can set: temperature (°C), time, flap opening (%), and fan speed (%).

I have asked my contact person about the flap opening and fan speed settings, but they could only suggest me to read the manual. I did, and there is no information on how fan speed and flap opening influence the soil probes. I also don't know what combination of settings achieves exhaust air.

If anyone can clarify the two points above highlighted in bold, it would be greatly appreciated. My background is nature protection and I have never worked with soil before.


13:20 UTC


Planting Grass - How much does my soil matter?

I purchased a spec home that was built over a previous farmers field in Utah about a mile north of Utah Lake. I am trying to grow new grass from seed (first time) and it is starting to come in, but every single person who has looked over my soil has told me conflicting things about it. So not really sure what I should do here:.

On advice I went and dug a deep hole and then did a jar test for my soil composition which looks something like this:

  • Original Soil is a farmers field that is very organic and even has horse/cow manure in it. Very smelly. But you have to dig down about a foot to hit it. This stays perpetually wet because we have a high water table. I didn't jar test any of this as it is really deep and probably the best soil I could ever ask for.
  • The builders put about 8 to12 inches of basically 100% silt ontop of this. I did a jar test, no sand appeared in the first 10-15 minutes, and then the entire thing congealed into a solid mass by hour 4 with basically no changes after 24+ hours for clay and clear water sitting at the top.
  • I regraded parts of my yard with anywhere from 1/4th to 5 inches of topsoil/fill dirt which is about 60% sand / 40% silt with basically no clay with the jar test. So as far as I can tell I have sandy loam, but just barely otherwise it would be silt loam.

I currently have a very patchy amount of grass growing over the sandy loam and parts of it are also starting in the silt. I've been looking at the dirt pyramid and I am completely confused about what I should do here. As far as I see it my options are:

  1. Just throw more grass seed down with peat moss top-dressing and call it good. Some people tell me it will grow deep and hit the low water table/good soil, others say that it won't get more 2-3 inches deep roots and that I will have to water my grass constantly and I am making a bad decision.
  2. Till/aerate my entire 4000sqft yard, get 2 inches of compost, till the yard again to reincorporate, and then wait until fall/next spring and replant grass seed and try again.
  3. Dig out the soil and re-grade with 4 inches of screened topsoil.

I feel like with grass you can constantly play a "optimization" game where conditions can always be better but what conditions are good enough? Can I just plant now and occasionally place down more peat moss/compost season over season when I go back to overseed? Or is my soil composition going to screw me super hard and I should ensure it is done to a feasible standard and just reset?

My goal isn't to do anything too crazy or expensive. I just want to have a reasonably easy to maintain lawn that won't require constant watering and be somewhat drought resistant. I am seeding 50% Kentucky Bluegrass, 25% Perennial Rye, and 25% Creeping Red Fescue. Just want to make sure my soil is good enough to grow reasonably deep roots.

Thank you for any feedback.

05:03 UTC


I just bought a house with an unknown oil spill... I do not know the severity

18:25 UTC



Hello all I am looking for some advice. I have a small plot (320sqm) of land that I want to use as my experimental plot. The soil is heavy clay that used to be farmed many years ago, before being a vegetable garden and now has been sitting for a few years. I want seed in a wild flower mix along with a green manure/ crop mix. My question is would sowing around August be too late in the season? Am I better off leaving the current grass cover and sowing next spring? I ultimately (long term) want to create a natural orchard so will be working towards building the soil health that benefits wood perennials. Thanks you in advance for any assistance.

08:11 UTC

Back To Top