The growth performance and reproductive allocation of Avena sativa under density and nitrogen interaction

In order to study the response of the growth and reproductive allocation pattern of oats to competition density, nutrient addition and their interaction, a pot experiment was conducted with different planting density and level of nitrogen addition. Plant height, leaf length, panicle length, tiller number and each organ biomass of oats significantly increased (P0.05) with the improvement of nitrogen addition level under the same density level. The plant performance with high nitrogen fertilizer (2 g·pot-1) were significantly greater (P0.01) than that of the other treatments. Meanwhile, the nitrogen fertilizer promoted the oats plant growth, improved plant photosynthesis and increased tiller numbers and nutrients accumulation. Most of test traits decreased with the increasement of density addition which performed competitive effects under the same nitrogen addition level. There were no significant interact effects of planting density and nitrogen addition level. Each growth index of oats significantly positive correlated with each other under interactions between density and nitrogen addition. The reproductive biomass allocation under interactions between high density and medium nitrogen addition (HD×MF) reached 12.23%. There was “shift” trade-off relationship in resource allocation of each organ of oats. The reproductive growth and allocation strategy of oat population is to increase organ allocation by restricting resources and reducing organ allocation access to non-restricted. The rule is consistent with the most optimal allocation theory.