Small amounts of ammonium (NH$ _4^+ $) can increase growth of maize (Zea mays). Issue 6 (16th September 2016)

• Record Type: Journal Article
• Authors: George, Jessey; Holtham, Luke; Sabermanesh, Kasra; Heuer, Sigrid; Tester, Mark; Plett, Darren; Garnett, Trevor
• Is Part Of: Journal of plant nutrition and soil science. Volume 179:Issue 6(2016:Dec.)
• Page Start: 717
• Page End: 725
• Publication Date: 2016-09-16
• Subjects: ammonium -- nitrate -- ion fluxes -- N uptake -- N budget; Plants -- Nutrition -- Periodicals; Soil science -- Periodicals; 630
• DOI: 10.1002/jpln.201500625
• Languages: English
• ISSNs: 1436-8730

Abstract

Abstract: Nitrate (NO$ _3^ - $ ) and ammonium (NH$ _4^+ $ ) are the predominant forms of nitrogen (N) available to plants in agricultural soils. Nitrate concentrations are generally ten times higher than those of NH$ _4^+ $ and this ratio is consistent across a wide range of soil types. The possible contribution of these small concentrations of NH$ _4^+ $ to the overall N budget of crop plants is often overlooked. In this study the importance of this for the growth and nitrogen budget of maize ( Zea mays L.) was investigated, using agriculturally relevant concentrations of NH$ _4^+ $ . Maize inbred line B73 was grown hydroponically for 30 d at low (0.5 mM) and sufficient (2.5 mM) levels of NO$ _3^ - $ . Ammonium was added at 0.05 mM and 0.25 mM to both levels of NO$ _3^ - $ . At low NO$ _3^ - $ levels, addition of NH$ _4^+ $ was found to improve the growth of maize plants. This increased plant growth was accompanied by an increase in total N uptake, as well as total phosphorus, sulphur and other micronutrients in the shoot. Ammonium influx was higher than NO$ _3^ - $ influx for all the plants and decreased as the total N in the nutrient medium increased. This study shows that agriculturally relevant proportions of NH$ _4^+ $ supplied in addition to NO$ _3^ - $ can increase growth of maize.