ball python in grass with fertilizer.

hello all,
lurker here.

I sat my ball python in a field of grass and he attempted to burrow his nose deep into the soil a few times, didn't think this would hurt him in anyway.
anyways.. turns out a month ago someone threw fertilizer all over the yard, unsure if this will effect the snake or not.
also a fly had landed on his back and I flicked it away after it being there for about 3 seconds or so.

I may be over-reacting but I'm just really trying to reach the full potential in snake care as I really do care for my snakes,

any comments as to the events here?
thanks in advance :)

What kind of fertilizer? Has it rained since it was applied? How much?

Wouldn't worry much about the fly landing on your snake, but depending upon where you live, more about what parasites were waiting in the grass to get onto
or into your snake. Nice little things like hookworms & ticks...& pathogens carried by wild creatures. Personally, when I take a snake outside for fresh air & a
little natural sun, it doesn't leave my hands...much as they'd like to.

I live in las vegas so I sorta doubt parasite travel, more or less just worried about bacteria.
bacteria and ofcourse in-sensitive chemicals and other materials like fertilizer.
but yeah I think it was just normal fertilizer.

just asking around trying to figure out if this is a serious enough situation

I meant chemical fertilizer or cow manure...? No idea what you mean by "normal fertilizer", lol.
Probably fine, but like I said, not something I do anyway.