The reproductive allocation of Avena sativa under different planting densities and nitrogen addition treatments

To study the response of the growth characteristics, biomass accumulation and biomass allocation pattern of Avena sativa to planting density and nutrient addition, a pot experiment was conducted with different planting densities and different levels of nitrogen addition. The results showed that the plant height, leaf length, panicle length, tiller number, root biomass, shoot biomass and reproductive biomass of A. sativa differed significantly (P<0.01) in the different density levels; as plant density increasing, reproductive biomass allocation increased, while belowground biomass (root) allocation decreased; shoot (leaf and stem) biomass allocation decreased along with plant density and then increased afterwards. Nutrient addition increased both vegetative and reproductive biomass. Nutrient addition had more effect on shoot biomass than root biomass. Reproductive biomass allocation: F1 (no nutrient addition) ≈ F2 (low nutrient addition) >F3 (medium nutrient addition) ≈ F4 (high nutrient addition), i.e. A. sativa exhibited high root biomass allocation and shoot biomass allocation in F1. In general, to obtain limited resources and optimal biomass allocation and to adapt to biotic (e.g. plant density) and physical (e.g. nitrogen addition) environment changes, there’s a trade-off between the below-ground biomass allocation and between vegetative-reproductive biomass allocation of A. sativa in different treatments.