It is my fanon that outputting the ideal fertilizer for the crop you are working with is part of Earth Pony magic. So, in effect, Earth Pony agriculture is much more competitive with human methods than it looks. It might even be breaking some biological facts, or even performing small amounts of transmutation to create elements that weren’t present in the Pony’s diet that their magic detects that the plants never-the-less need.
 
Some Earth Ponies learn to consciously control this effect (for instance to grow wine grapes or perhaps “Vidalia” onions, which require a specific sort of biologically deficient soil).
 
I further fanonize that the transition upon getting an agriculture-based cutie-mark is sufficiently disruptive that Applejack and Big Mac had an special toilet seat (enchanted for comfort) ready for when ‘Bloom got her mark. They quietly sold it when she got a non-agricultural mark so that she wouldn’t get the mistaken idea that they weren’t proud of her.

@Ping_chan  
Nah, man. There is no need for waste production as they are efficiant enough to use it all as fuel. Perhaps they can deficate and urinate synthetics as a decoy though!

I wonder if synths poop inorganic poop? Like synthetic poop?

@Dirty Bit  
Hey, it’s as organic as you can get

Oh, that Tater…

Now that’s what I call vertical systems integration.

@ShimmeringStallion  
Oh dear God I didn’t want to see the potatoes like that!

“Wait, the veggies or the fertilizer?”  
“……………… Yes.”

@Stotter  
:p

@Background Pony #B008
 
@Ping_chan  
I forgot to explain the acronym (magically modified organisms), but this turned out funnier.

@Background Pony #B008  
I once tried maxing our my agriculture skill while working quests at a Unicorn farm, it was lots of fun during the first free month, but after the 29th day the greedy little horned bastard started charging me $29.99 per month!  
I went back to mining fish over at Ragnarok.

@Stotter  

 
Unicorn crops have MMOs in them! If you eat their potatoes you turn into your World of Warcraft character! If you put too much unicorn-grown fruit in one place it opens a portal to Eve Online and then you get invaded by Goonswarm! And then there was the time customers turned into their Second Life characters…

I’ve heard good things about Unicorn agriculture, but it’s having trouble getting support to due to false rumors about MMOs being dangerous.  
For example, a giant apple only exploded that one time, and it was the fault of an earth pony filly learning potions.
 
What about those times with the parasprites and vampire fruit bats?
 
Lesson learned: no modifying the feeding habits of critters. Progress involves trial and error.
 
And the living apples?
 
We consider that night non-canon.
 
Isn’t this interview based on something even less canon?
 
After a question that damaged the fourth wall, Pinkie gets dragged off, thus ending this interview.

@Background Pony #D98B
 
I’ve seen the book cover.
 
@NudistHorse
 
The book is just about that; the metal album cover on the other hand is grimdark. I don’t know a lot about this subject but my Dad did dig up long abandoned outhouses in search of old bottles and whatnot, 70+ years after the sites were left.

@laofuzi  
That’s kinda weird to think of synthetic soil, but what do I know, I know more about fixing motherboards and bent cpu pins (back when they actually had pins that you could accidentally bend) than planting stuff in the ground…  
BTW I actually did try planting money in the ground once before, to see if I could get my money to grow, it didn’t work, so I’ve given up on investing my money naturally…  
One of these days I’ll figure out bitcoin mining…

@Ping_chan  
Yes, it’s called ammonium phosphate

So… Is there such a thing as Non-organic soil?

Do you also use Luna’s personal night soil ??

@Background Pony #D98B  
I’d rather not. ._.

I always wash my veggies before preparing meals, just in case.

So, it’s very organic.

Humans do this too. Look up “humanure” some time.

That…
 
Actually makes sense.

Earth ponies and earthworms compete fiercely for this environmental niche.

In. Out.
 
It’s the perfect cycle.