its different but the same

March 4, 2010 12:09 PM

Help me explain the difference between dirt and soil to my 4 year old son.
posted by ducktape to Home & Garden (27 answers total)

Dirt=crushed rocks. Soil=crushed rocks+dead (well, decomposed) stuff.
posted by amelioration at 12:11 PM on March 4, 2010

Are they different?

Soil is dirt with plant food added.

Dirt is like an empty plate where as soil is like a plate filled with cake.
posted by royalsong at 12:12 PM on March 4, 2010

Dirt has dead stuff.

No pile of crushed rocks is sterile.
posted by dfriedman at 12:16 PM on March 4, 2010

It's not different. They are synonyms. Look the words up. The first definition for dirt is soil.
posted by Pollomacho at 12:24 PM on March 4, 2010 [1 favorite]

Response by poster: odinsdream - thats our project for the weekend.
posted by ducktape at 12:24 PM on March 4, 2010

Dirt and soil are synonyms.

Crushed, powdered rock is called regolith.
posted by General Tonic at 12:25 PM on March 4, 2010

I remember a soil science professor that would flip out if someone called it dirt, instead of soil. Generally soil is the term for the whole system of minerals, nutrients, organisms and organic matter. Dirt is just schmutz.
posted by electroboy at 12:38 PM on March 4, 2010

We had an agriculture teacher in the public school I attended in Douglasville, GA. He used to say "If it's outside, it's soil. If it's inside, it's dirt."

In other words, it depends on context - if there are plants growing in it, or there could be plants growing in it, or if it's being useful in some other way, it's soil. If it's messing up your carpet, if it's making something "dirty", then it's dirt.
posted by amtho at 12:40 PM on March 4, 2010 [2 favorites]

Is your kid getting confused by the pejorative use of "dirt"? We say bad things about dirt (cheap as, old as, __y liar, etc), but we buy potting soil in nice plastic bags with pretty flowers.

Is a 4-year old capable of grokking metaphor as distinct from literal meaning? (I have no idea.) If so, maybe explaining the metaphorical meanings of dirt might clear up some confusion.
posted by Quietgal at 12:44 PM on March 4, 2010

Going with General Tonic and others, here. Dirt and soil are the same thing.

I did have a soil mechanics lab professor who used to tell us (civil engineering students) that the difference between dirt and soil was about $50 an hour. (adjust for inflation as necessary)
posted by dforemsky at 12:48 PM on March 4, 2010 [1 favorite]

electroboy must have had the same soil science teacher I had. :) Soil is the parent material (eroded rocks), organic matter, organisms. Dirt is cruft, like the nasty black road stuff all over your bike after the rain, or the grey crust on the earpiece of your cell phone.
posted by oneirodynia at 12:50 PM on March 4, 2010

Meant to add: people that work with soil don't call it "dirt".
posted by oneirodynia at 12:51 PM on March 4, 2010

when it is on your pants or the floor it is dirt.. when something is growing in it, it's soil..
posted by jockc at 12:51 PM on March 4, 2010 [1 favorite]

I when to college with a bunch of aggies. They get very mad if you say soil and dirt are the same thing. Plants grow in soil; it's alive. Dirt is what gets stuck to your clothes or your car's engine block.
posted by chairface at 1:10 PM on March 4, 2010

Just an extra fact to throw in: in the UK, we never use the word 'dirt' to refer to soil. We call it soil or earth. Soil can be dirt, but only when it makes something else dirty.
posted by le morte de bea arthur at 1:20 PM on March 4, 2010 [1 favorite]

I always thought the soil science prof should hang out with the engineering materials lab manager who would flip out if you referred to asphalt (or bitumen) as "tar".

"No, goddamit! Tar comes from pine trees, asphalt is a petroleum product! Those goddamn LaBrea tar pits are lakes of goddamn asphalt!"
posted by electroboy at 1:26 PM on March 4, 2010 [1 favorite]

I'm a fan of the Mary Douglas distinction:

Soil is the stuff plants grow in.

Dirt is 'matter out of place.' Thus coffee isn't dirty until it's spilled on your white shirt. Soil isn't dirt until you track it inside. 'Dirt' isn't a fundamental type of matter, but a social concept for how we understand matter which violates our social categories.
posted by farishta at 1:32 PM on March 4, 2010 [8 favorites]

My dad, a horticulturist, always told me "dirt is what you find under your fingernails."
posted by illenion at 1:48 PM on March 4, 2010

I think it's a difference of connotation. I remember seeing bumper stickers when I lived out West that read, 'Stop treating our soil like dirt.'
posted by workerant at 1:50 PM on March 4, 2010

Soil is a subset of dirt. Soil is useful dirt with particular properties - Dirt isn't necessarily soil, it could be greasy, dusty, gummy, rocky, sandy, etc.
posted by Gor-ella at 1:53 PM on March 4, 2010

Soil connotes growth potential. Things grow in soil. Dirt is soil with no growth.
posted by jckll at 1:57 PM on March 4, 2010

My college soil science professor said that dirt is misplaced soil. He had a bumper sticker to that effect on his office door.
posted by look busy at 2:03 PM on March 4, 2010 [1 favorite]

As in most matters, I think we can look to Rowlf the dog for our answer. In his late 70's Arbor Day Foundation commercial he sings, "Be it ever so humble, there's no dirt like soil", and then goes on to extol the virtues of soil, and discuss (with Fozzy? I can't remember) how it is the medium in which plants and trees grow, and is a precious subset of the dirt family.

I could not find it on Youtube.
posted by dirtdirt at 2:09 PM on March 4, 2010

Dirt is what you get on your clothes when you brush up against a car in Fairbanks in the spring. Soil is what you plant in.
posted by northernlightgardener at 2:15 PM on March 4, 2010

Heh. Just saw a screening of "Dirt. The movie." - it's a charming documentary about exactly this, and more. Recommended.
posted by dbmcd at 3:03 PM on March 4, 2010

My father-in-law the plant pathologist says "Dirt is soil that's in the wrong place."
posted by uberfunk at 7:16 AM on March 5, 2010

I think some of you have soiled your pants over words, while ignoring inconvenient uses of the words that don't fit your notions.

Except that mostly it's correct enough in common usage. But seriously, "soiled" and "dirty" are the same word. Interestingly, no one has brought up the word "loam", which is the kind of dirt I was taught to use for potting soil.
posted by Goofyy at 10:29 AM on March 7, 2010