Yes, SOYBEAN is a Scrabble word!

Letter values in Scrabble US: S 1, O 1, Y 4, B 3, E 1, A 1, N 1.

Is it a valid word?

SOYBEAN is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a source of oil; used for forage and soil improvement and as food
erect bushy hairy annual herb having trifoliate leaves and purple to pink flowers; extensively cultivated for food and forage and soil improvement but especially for its nutritious oil-rich seeds; native to Asia
the most highly proteinaceous vegetable known; the fruit of the soybean plant is used in a variety of foods and as fodder (especially as a replacement for animal protein)

Also: soya bean, soybean plant, soja bean, glycine max.