Water and nitrogen interactively increased the biomass production of Jerusalem artichoke (Helianthus tuberosus L.) in semi-arid area
The response of height, aboveground and underground biomass of Jerusalem artichoke (Helianthus tuberosus L.) to water and nitrogen fertilization were studied in north-eastern Inner Mongolia, China. The results showed that water was a main limiting factor on the height and yield of Jerusalem artichoke; it significantly improved the height and yield of Jerusalem artichoke (including leaf, stem, root and tuber yields) (p<0.01). Nitrogen fertilizer significantly influence height and yield during irrigation and achieved higher yield during addition of nitrogen (25-50 kg ha-1) (p<0.01). On the contrary, it was not significantly influenced without irrigation. By analyzing the correlation among tuber, leaf, stem and root, stem-leaf ratio, root-tuber ratio and root-shoot ratio under different condition (including irrigation and no irrigation), leaf size showed significant positive correlation with stem size and negative correlation with root-shoot ratio and root-shoot ration in two different conditions; during irrigation, leaf size indicated significant positive correlation with tuber size and the positive correlation between leaf and root size was not significant (p<0.01); without irrigation condition showed significant positive correlation between leaf and root size and the positive correlation between leaf and tuber size was not significant (p<0.01).
Key words: Helianthus tuberosus L., yield, height, irrigation, nitrogen addition.