Abstract
The effect of nitrate nitrogen in culture solution on the growth of waterhyacinth, the absorption of nitrate nitrogen and the nitrogen contents of tissues of waterhyacinth were studied.
(1) The contents of waterhyacinth and total nitrogen of waterhyacinth and specific absorption rate of nitrate nitrogen increased with increasing concentration of nitrate nitrogen in culture.
(2) It is clear that nitrate nitrogen is limiting below a concentration of 0.6mg·l-1 and concentrations higher than this exert less influence on the nitrogen content of the plant.
(3) When nitrate nitrogen are present in excess (above 0.5mg·l-1), the value of the specific growth rate of waterhyacinth remain constant.
