Effect of sodium on the growth of and ion uptake by barley, sugar beet and broad beans

Abstract

SUMMARYThe effect of soil salinity (ECerange 2–9 mmhos/cm) on the growth of and ion uptake by barley, sugar beet and broad beans (crops increasingly sensitive to salinity) was investigated in a glasshouse experiment.Barley and sugar-beet yields benefited from the added Na in the soil but broad beans were always adversely affected. Changes in growth and ion uptake are discussed in terms of Na:K synergism and antagonism.Sodium:potassium antagonism was observed in barley just after germination, and in sugar beet throughout growth, but not in barley at other growth stages nor in broad beans. Greater Na uptake promoted increases in dry-matter yields of all plant parts with barley and sugar beet, indicating that Na played a specific role in their metabolism. In sugar-beet roots, sugar concentrations and dry-matter yields increased with added Na by half as much more than without added Na, suggesting that Na is an essential nutrient.We conclude from our experiments that the effects of salinity caused by Na salts when water is not limiting, is related not only to plant species but also to their stages of growth.