Response of wheat plants to different levels and forms of nitrogen

Indian soils are deficient in nitrogen and nitrogen use effeciency is between 33-50% depending on the crops. The present experiment was conducted to find out the response of wheat to different N supply and forms. It was noticed that wheat is sensitive to ammonia and N limiting conditions. Wheat seedlings (var. PBW 343) were grown under four different N treatments and various parameters of growth and N-assimilation were studied. Growth and nitrogen metabolism was enhanced in seedlings under high NO3 --N when compared to those grown with low and without N. The growth of the wheat seedlings was severely inhibited in terms of biomass accumulation, leaf area in NH4 +-N and zero?N treatments. Root : shoot ratio was enhanced in zero- N and ammonium grown plants as compared to the nitrate N fed wheat seedlings. There was a relative increase in shoot length by 20% to 40% in the seedlings grown in solution having N salts. In zero-N and ammonium fed plants the nitrate levels, total reduced N and total soluble protein content was significantly lower as compared to both low and high NO3-N grown wheat seedlings. These parameters directly correlated with low NR activity in zero-N and NH4 +-N treatments.