If you like Hengfeng, you shgould also check out Migao ("MGO") which is also a China fertilizer play. As of now MGO is trading around $3.68 and its 52 hi-low is $11.97 - $2.76.
A friend of mine did a lot of research on this one after he got this lead from attending a stock guru's seminar last year. It's a solid sleeper play.