Vintage TEXAS VOCATIONAL AGRICULTURE TEACHERS pin.  Maybe the 10 one the wheat is for 10 years of membership?  Not sure.  This nice older pin features the state of Texas with a wheat shock in the middle that has the number 10.  Blue enamel border with a 5 pointed Texas Star surrounding it.  Each point of the star has one of the letters of Texas.  Sort of nifty for your farming collection (or to replace the one you lost) 
It is in good vintage condition.  The post shows some wear- it is a different metal and is a bit softer.  The clasp/holder thing on the back is unusual, not damaged, just sort of different from most pins.  It screws and slides (but I haven't figured out what the screw part is for- doesn't seem to do anything).
Check out my other farming items and my huge pile o' lapel pins.  I have several styles of FFA (Future Farmers of America) and Vocational Ag pins. 
If you need additional photos or have any questions, please let me know.  I'll be happy to try to help.
From my non smoking home.
Check my stuff for more beautiful items that catch my eye!  I have a pretty eclectic collection of stuff and add new items almost daily.