Aboveground biomass
Before the pod color turned from green to brown or blank, each plant was bagged loosely with a 1-mm nylon mesh to prevent seeds from splashing. At maturity, 10 plants of each material were randomly selected and then dried for one week at 70 °C, and total biomass was recorded using a balance (PB602-N, Mettler Toledo, Nänikon-Uster, Switzerland).