Chou Collection, Middle Volume
Radical: Earth (tǔ)
Character: Fo
Kangxi strokes: 8
Page 226, Entry 32
Broad Rhymes (Guangyun), Collected Rhymes (Jiyun), Rhyme Meetings (Yunhui), and Correct Rhymes (Zhengyun) state it is pronounced fo. Fo describes the appearance of dust blowing in the air.
Han Yu, Poem in Response to Chancellor Zheng (Chou Zheng xianggong shi): The grand standard moves forward in a cloud of dust.
Also, Collected Rhymes (Jiyun) states it is pronounced bie. The meaning is the same.