The effect of different seeding rates and nitrogen levels on aboveground shoot and root biomass (g plant−1) of Ischaemum rugosum.

Shoot data were fitted to an exponential decay model: Y = y0+a×e−bx, where Y is the shoot biomass (g plant−1) at different seed rates (kg ha−1) x, y0 is the minimum shoot biomass at seed rate 100 kg ha−1, y0+a is the maximum shoot biomass at seed rate 0 kg ha−1, and b is the slope. Root biomass data were fitted to an exponential decay model: Y = ae−bx, where Y is the root biomass (g plant−1) at seed rate x kg ha−1, a is the maximum root biomass (g plant−1) at seed rate 0 kg ha−1, and b is the slope. Parameter estimates are followed by standard error in parentheses.