Q Nonsensitive Clearance timing

Hello, I have accepted a job with USDA and it requires Q Nonsensitive clearance. I currently have Secret clearance that will expire in July 2017. Based on my research it appears that I have to fill out SF 85 for new Q Nonsensitive clearance job. Is this correct? Here is some back ground about my employment.

Currently federal employee
-Cleared in May 2007 by DoD for secret level. Favorably adjudicated after filling out SF 86. Switched job after a few years. .
-Cleared for Public Trust position in January 2011. Favorably adjudicated after filling out SF 85P. Then switched job after about a year later.
-Filled out SF 86 in May 2012 was adjudicated favorably. This was a public trust position but my agency never requested any clearance level for me. Switched job again after few years.

My question is since I am applying for a job that requires low level of clearance (Q Nonsensitive), does that mean I have fill out SF 85 again? If yes, when will it needs to be completed? Or will my new agency accept the clearance from 2011 or 2012 because it was at a higher level? I don’t mind filling out the SF 85 if I have to. Could you please assist or provide an answer to my question?

Lets be clear in our terminology going forward:
Nonsensitive (SF-85) = no security clearance
Nonsensitive Public Trust (SF-85P = no security clearance
Noncritical Sensitive (SF-86) = Secret clearance

You say you currently have a Secret but you current job is considered a public trust position, so that does not make sense. Regardless, if you are a current federal employee with a favorably adjudicated background investigation (any level) then under reciprocity guidelines a new investigation is not required unless a new issue has popped up since the last investigation.

My understanding is there is no reciprocity among different agencies? I have a current public trust and I am leaving my agency to join another that requires a public trust. The new agency wants to conduct another public trust BI.