The relationships in the uptake of the different cations and anions of both major and some minor elements were studied at two stages of growth in the recommended IRRI strains of rice grown in Bangladesh Agricultural University Farm, Hymensingh under various seasons and local strains of rice at tillering stage growing in different zones of Bangladesh under aus season.
The m.ež z cations varied directly with % N in all the zones of local and IRRI strains irrespective of stages of growth and seasons. A synergistic effect was observed between potassium and nitrogen; nitrogen and phosphorus; and phosphorus and potassium. But mature stage of IRRI strains of any season did not confirm the truth of synergism between nitrogen and phosphorus and the mature stage of IRRI under aus did not show any increasing or decreasing trend of potassium with the rise in phosphorus content. Direct correlation between % N and m.e% z anions and m.ez cations and m.e% anions existed in rice plants irrespective of strains, growth, seasons and zones. The rise in the uptake of the divalent ions Ca+++ Mg++ was attended by a fall in that of the monovalents Na+ K. This picture was observed in local strains of rice of different zones under aus season; but no relationship between these ions was noticed at maturity of aman whereas boro and aus season at maturity indicated inverse relationship between divalent and monovalent ions. Aman at tillering of IRRI strains showed the same truth when combined with local strains and boro at the same stage did not indicate any relationship. Antagonism was also observed between magnesium and potassium and calcium and potassium. Chlorine and sulphur showed practically no relationship between themselves but at some stages in some season when the local strains were compared with the exotic IRRI strains gave antagonistic characteristics. No relationship was found between iron and manganese; chlorine and manganese showed the same truth but IRRI strains at maturity under boro gave positive relationship. Nitrogen and molybdenum and nitrogen and manganese did not confirm any relationship between each other i.e. molybdenum and manganese m.e% neither increased nor decreased with the rise in nitrogen m.e%. So major mutrient nitrogen was without any relationship with trace elements. Another major element phosphorus was found to be in agreement with this truth showing no increasing or decreasing trend of Mo and in with its rise in uptake. The feebly arid zone with local strains confirmed antagonism between sulphur and manganese