Biomass allocation and growth analysis of Panicum virgatum ramets under two planting conditions in Songnen Plain

Using a random sampling method, the plasticity and regularity of biomass allocation of ramets in switchgrass (Panicum virgatum) planted in sandy and saline-alkaline soils were analyzed at the milk-ripe and wax-ripe stages. The results showed that differences in the plant height and aboveground biomass of switchgrass between the two planting conditions were extremely significant at both stages (P < 0.01). The average aboveground biomass of each component in the sandy soil was 2.08～3.32 and 1.60～1.97 times that in saline-alkaline soil at the milk-ripe and wax-ripe stages, respectively. Plant height, total biomass, and biomass of each component of ramets in the switchgrass increased with increasing ramet height and aboveground biomass, indicating an extremely linear isogonic or allometric growth of power and exponential functions under both planting conditions and at the two growth stages. The height growth and biomass allocation of switchgrass ramets show both great ecological plasticity and strong adjustability.