) Glycine maxl.( بر رشد رويشي و گره بندي گياه سويا )KNO3( تاثير نيترات پتاسيم

Effect of nitrate (KNO3) on growth and nodulation in soybean (Glycin maxal)

Nitrate can affect growth, development and biological nitrogen fixation (BNF) in legumes. Application of nitrogen fertilizers might be necessary for more production in these crops. Therefore,this study was conducted to examine effect of various KNo3 concentrations (0,1,3,5 mM) on nodulation, nodule growth ,BNF and dry matter prodution in two soybean caltivars (Sahar and Williams) using sand culture and nitrogen free nutrient solution. Results showed that nodule number&nodule fresh weight are declined with increasing nitrate concentration, but shoot and total dry weight,nitrogen percentage and nitrogen yield are increased, Nodule number, nodule fresh weight, leaf area, leaf stem, root , total dry weight and nitrogen yield were higher in Williams than in Shahar, However, shoot dry weight, nitrogen percentage and root/shoot ratio were higher in sahar. root 1 shoot ratio showed a decreasing trend with incrcreasing [KNo3 ] . The highest number of nodules was observed in cv. Williams and 0 mM[KNo3] . The lowest root/shoot ratio was found in cv.Sahar and 0 mM [KNo3] But was decreased with increasing nitrate concentration. Higher nitrogen content and dry matter production was due to facilitated nitrogen uptake from growth medium.