@gmslave i think you got the N backward. it's more available at higher pH. that's one of the main reasons the recommended pH for soil is higher, because it's tougher to get N out of soil - whether due to microbes involved, physical obstacles, whatever.. i don't know the nitty-gritty details of causality, unfortunately.
extra tidbit for answers.
i wouldn't trust those 'growweedeasy' ph charts.. i think they are a bit suspsect on the information they provide, but .. oh well. i wouldn't trust it without verifying what it says through actual research conducted on this stuff...
Most plants researched prefer the same narrow range of concentrations and ratios of nutes. marijuana is not different from this very common grouping of plants. So, most research will apply well in this regard to other species.
in this particular case, it kinda shows what i'm talking about that so-called pH chart. N is a solid bar across whole spectrum of "hydro" chart, and you can see the lower end on the "soil" chart. in this case, they got it right. More likely made by people that took a high school chem class and didn't do well.
but, if you study that chart... at <6 you will inevitably have deficiencies and problems... if that's true why do people recommend 5.5-5.8? Why aren't those people constantly having Mg, Ca, Mn defieciencies? That chart is trash, that's why, lol. generalizations only... if its range is 'higher' figure a higher pH could help. beyond that don't use it in a specific, precise, black-and-white way. those charts are not accurate in ways that can worsen problems.
right now, most science is butchered by this industry for money.