Nitrogen Nutrition of Broad Beans as Influenced by Soil Salinity

Abstract

A pot experiment was carried out to study about the effect of nitrogen fertilization under soil salinization conditions on growth, nitrogen content and yield of edible broad beans. Soil salinity was adjusted to be 0.18 (cont.), 0.30, 0.45 and 0.60% of oven dry soil. Nitrogen fertilizer was applied at rates of 0, 25, 50 and 75 mg N/4 kg soil/pot. Obtained results were as follows : 1) Except for the low salinity level of 0.30% which proved to be promotive, the higher the soil salinity level the lower were the dry matter content, nitrogen content, seed yield, stem weight, number of pods per plant and protein content in seeds per plant. However, all salinity levels including low one were depressive on the weight of 100 seeds as well as the protein concentration in seeds. 2) The mean values of dry matter content, at pre-flowering and pod formation stages, as well as seed yield per plant and weight of 100 seeds were increased with each increase in applied nitrogen fertilizer. 3) Nitrogen content in plant as well as the number of pods per plant and protein content in seeds, was also increased by all investigated rates of nitrogen fertilizer, though, the medium rate was the most promotive one at both pod filling and maturity stages. 4) A positive highly significant correlation was found between the final seed yield and dry matter content in plant at both pre-flowering and pod filling stages. 5) The efficiency of seed yield production was increased with increasing the rates of applied nitrogen. The above results could conclude that a) the salt concentration of 0.45% in soil was the critical level for the growth and development of broad beans, and b) nitrogen fertilization along with seed inoculation with Rhizobium is significant for maximum seed yield in soils with low inorganic nitrogen content. © 1986, CROP SCIENCE SOCIETY OF JAPAN. All rights reserved.