Effect of Na/Ca and Na/K ratios in saline culture solution on the growth and mineral nutrition of rice (Oryza sativa L.)

Summary A study was conducted to evaluate the effect of manganese on accumulation of Zn, Fe, Cu, and B by different soybean genotypes under varying soil pH conditions, in view of determining tolerance towards extremes in soil pH and mineral toxicities. Enon sandy loam soil was used for the investigation in a greenhouse. Manganese rates were 0, 10, and 20 kg/ha. The pH levels were 5.3, 6.3, and 7.0. The soybean genotypes tested were PI 159319, PI 324924, PI 960895, and L-76-0132. Results indicate that Zn concentration in the genotypes leaf and seed was not affected by Mn application whereas the Cu concentration in the leaf was affected. In general, there was an increase in concentration of Fe in the genotypes seed with Mn application. Boron concentration in the genotypes leaf and seed was unaffected by Mn application. The effect of soil pH on Zn, Fe, Cu, and B in the genotypes tissue was significant. This did not result in toxic levels of the elements in the tissues.Contribution of the Department of Plant Science and Technology, North Carolina Agricultural and Technical State University, Greensboro, N.C. 27411, and Agronomic Division, North Carolina Department of Agriculture, Raleigh, NC 27611, USA