Minecraft Carrots?

I'm grind on Minecraft as normal and just wanted to start a carrot farm, I made the whole underground and put it in a little wood look, so:
Carrots (around 7 blocks), then water and then I just wanted to put carrots there again, but I can't put the carrots on the last two blocks.

Do you know maybe what that could be?

(Games btw on 1.16.4, on the PC)

Is it the light?

Yep, I didn't think about that at all, I've now placed a torch, thanks ^ - ^

One water block is enough for 4 blocks in each direction.