Influence of Nitrogen Fertilization on Root Growth Dynamics and Yield of Chia (Salvia hispanica L.) in Greenhouse Pots

A greenhouse pot experiment was conducted in Western Greece in order to evaluate the effect of different nitrogen rates on the development of the root system and productivity of chia (Salvia hispanica L.) plant. The experiment followed a completely randomized design (CRD), with six treatments, different rates of applied nitrogen (0, 25, 50, 75, 100 and 125 kg ha-1 equivalent to 0, 134, 268, 402, 536 and 670 mg nitrogen pot-1). The results of this study showed that root length density (RLD) and root mass density (RMD) increased with the increased rate of applied nitrogen and the highest values (1.297 cm cm-3 and 1.178 mg cm-3, respectively) were found after the application of 670 mg nitrogen pot-1 at 100 days after sowing (DAS). Plant height (106.06 cm) and leaf area per plant (883.14 cm2) were significantly affected by the highest rate of nitrogen. Additionally, dry matter and seed yield per plant were clearly affected by fertilization, with the highest values (27.57 g and 4.20 g, respectively) obtained in plants treated with 670 mg nitrogen pot-1. In conclusion, increasing the levels of applied nitrogen up to 670 mg N pot-1 improves root development and therefore the yields of chia.