I'd be leery of planting wheat this fall... given the herbicides you used, and given the lack of rainfall you've experienced.   I fear it's a little too risky.

I probably would pull a few nitrate tests to see how much nitrogen I have in "storage".   But I think we need to recognize that whatever nitrogen is there now, may not be there next spring.   So it would probably be wise to pull nitrate samples again next spring.   There may not be any nitrogen left to take advantage of.  


gordon