Effect of Increasing Concentration of Bicarbonate on Plant Growth and Nutrient Uptake by Maize Plants

Abstract

2 Abstract: Increasing concentration of HCO ions in the nutrient medium progressively decreased the growth 3 - of maize plants as measured by decrease in shoots and root weight, these effects becoming more distinct with time, particularly at the two higher levels of bicarbonate supply (10 and 20 mM). Various parameter of growth including plant height, root and shoot measurements, nutrient composition of shoots and roots and nutrient uptake were all affected in this manner as was also the appearance of iron chlorosis. In the cation-anion balance data of the roots and shoots, mineral cation totals exceeded anion totals for each HCO treatment and in the 3 - accumulated on the root surface. Therefore, the specific effect on roots and shoots growth as compared with control may be due to inhibited respiration caused by high levels of bicarbonate treatments. understood. sheet, placed over the containers. To prevent the possible The purpose of this experiment was to investigate the occurrence of any anoxia compressed air was bubbled effects of increasing concentration of bicarbonate in the vigorously into the solution. For the first 2 days after nutrient medium on the growth of maize as measured at a transfer a half strength nutrient solution was used single harvest and to determine the uptake and (to prevent the plants suffering from osmotic stress). distribution of the main mineral nutrients. In this work This was then replaced by a full strength solution for a