The present invention relates to a plant nutrition formulation and method thereof, and more particularly to a plant nutrition formulated by recovery filtrate from non-woody fiber plant biopulping and method thereof. The present invention provides a plant nutrition formulation including steps of providing a culture solution containing a culture medium, a non-woody fiber plant material and microbial suspension, fermenting the culture solution for preparing a biopulping solution, filtrating the biopulping solution for preparing a filtrate, and formulating the filtrate for preparing a plant nutrition.