Nitrogen

Abstract

Rice (Oryza sativa L.) cultivars, Bhura Rata (BR), IR‐8 and Panvel (PNL‐1) were grown for 15 days and the effect of 100 mg/1 ammonium sulphate on Na and Cl absorption and transport was tested in solution culture after 3 hours. Ammonium sulphate reduced Na absorption from 0.1 and 10 mM NaCl in all cultivars, and more significantly in the salt‐tolerant BR, in which the transport was also reduced at 0.1 mM NaCl. Ammonium sulphate reduced transport of Na from 10 mM NaCl in IR‐8, a salt‐sensitive cultivar. Chloride uptake and transport from 0.1 mM NaCl were both reduced by ammonium sulphate in the salt‐tolerant BR and PNL.

The transport of Na, Rb, Cl, Fe and Zn from a saline Panvel and a non‐saline Trombay soil was examined by growing rice cultivars, AU‐1, AU‐42, BR, and PNL‐1, which are salt‐tolerant to varying degrees, and Jaya, a moderately salt‐tolerant cultivar which has been adapted to kharland (saline) soil conditions. Rb transport was much reduced in the saline soils in all the cultivars. There were differences between the cultivars on the translocation of Fe, Zn and Rb. In general, Rb, Zn, Cl and Fe uptake from saline soil were much less than from non‐saline soil, while Na uptake was higher in AU‐42 from the non‐saline soil. Growth was much more in BR than other cultivars in both types of soil. It was also better under ratooned condition. On an overall basis, BR is followed by Jaya and AU‐1 in their salt tolerance.

Key words:

• Sodium
• chloride
• absorption
• transport
• iron
• zinc
• rubidium
• rice cultivars
• saline soil
• ratoon