Effects of CaSO₄, CaCl₂, and NaCl on leaf nitrogen, nodule weight, and acetylene reduction activity in<i>Phaseolus vulgaris</i>L.

Abstract

Abstract Two forms of calcium were used to ameliorate the harmful effects of sodium chloride (NaCl) on total leaf nitrogen, nodule weight, and acetylene reduction activity in snapbeans, Phaseolus vulgaris L., cv Contender, Plants were grown in pots under greenhouse conditions and were irrigated with water containing NaCl with a salinity of 0, 44, 88, or 132 mM., In addition, either calcium sulfate (CaSO4)or calcium chloride (CaCl2) was added at concentrations of 0, 4, and 8 mM. When NaCl concentration increased, nodule weight and acetylene reduction activity decreased and total leaf nitrogen increased. Addition of Ca to the NaCl treatments slightly increased the total leaf nitrogen, nodule weight, and acetylene reduction activity of snapbeans. The positive effect on the measured variables in snapbeans by the addition of Ca compounds may be attributed to maintaining the selective permeability of membranes.