Temporal Monitoring and Assessment of Inorganic Nitrogen Content of Soil due to Nitrogen Fertilizers and their Related Cytotoxic Effects.

Background: Indian economy is largely based on agriculture. Major share of agricultural investments goes into chemical fertilizers. Nitrogen (N) fertilizers are used in fields to enhance the crop yield. Most of the reports are based on growth related data, morphological and yield related data but very few reports reveal the facts about genotoxic and cytotoxic effects of these fertilizers. Therefore, the present communication is an attempt in the aforesaid direction. Methods: In a pot experiment, mineral N content of soil in the form of ammonium-N (NH₄⁺-N) and nitrate-N (NO₃^--N) were analysed at regular interval of 5 days till 30 days after treatment (DAT). On the corresponding days root tip assay was done for cytotoxic analyses and also the temporal changes in NH₄⁺-N and NO₃^--N contents were observed. Result: In the Ammonium nitrate treatments, higher mitotic index (MI%) percentages were obtained. While for the Urea, NH4₊^-N content and MI were found to have a positive correlation. Also, it was found that there is an optimum ratio of NH4₊^-N and NO₃^--N in each treatment at which the MI% was the maximum. The study gives an interesting insight for the possible cytotoxic effects of the N fertilizers. [ABSTRACT FROM AUTHOR]