ALLEVIATION OF ALUMINIUM TOXICITY BY CALCIUM IN BRASSICA JUNCEA (L.) CZERNJ & COSSON

The ameliorative effect of Ca on Al toxicity was investigated on a crop plant (Brassica juncea L. Czernj & Cosson) that involved an affordable and practical method to contain the toxicity through soil amendments with some salts of Ca, which is available locally and plentifully. It was found that a dose of 1200 μg g–1of Ca as CaCO3 was sufficient to protect the crop from rhizotoxicity induced at 500 μg g–1 of Al. A comparative pot-culture study of different salts of calcium (viz. CaCO3, CaSO4.2H2O, CaCl2.2H2O) was made to find out its most suitable anionic moiety. It was revealed that the salt of CaCO3 worked the best, as it increased soil pH more than other two salts tested. Our study further revealed that local tubewell water irrigated Brassica plants were free from Al-induced toxic effects even at much less of Ca-salt applied to the soil. The findings were also supported by the biochemical analyses of Al and Ca.