Nitrogen Transformation in Waterlogged Soil in Indian Rice Fields: A Review
Rajat Kumar Parit
Department of Soil Science, Assam Agricultural University, Jorhat-785013, Assam, India.
P. K. Bharteey *
Department of Soil Science, Assam Agricultural University, Jorhat-785013, Assam, India.
Bishnu Jyoti Saikia
Department of Soil Science, Assam Agricultural University, Jorhat-785013, Assam, India.
Sarat Sekhar Bora
Department of Agronomy, Assam Agricultural University, Jorhat-785013, Assam, India.
P. K. Maurya
Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India.
Ruthy Tabing
Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Science, Uttar Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
No other element can match the essentiality of nitrogen in soil for growth and development of plants and its transformations among various forms viz., nitrite, nitrate, ammonium are mostly mediated by microbes. As its transformation depends on major microbial activity and thus, there is a huge difference between the transformation of it in aerobic soil and anaerobic soil. This difference mainly arises due to presence and absence of oxygen. The absence of oxygen in soil creates anaerobic condition and thus promotes the growth of anaerobic microbes. In submerged soil, applied nitrogen is lost in various forms such as volatilization, denitrification, leaching and runoff out of which ammonium volatilization causes the maximum loss. The recovery of applied nitrogen, as recorded from various filed experiments in India, has been found to vary from 28 to 34% for submerged rice. The chemistry of nitrogen in submerged soil is quite interesting for this review.
Keywords: Nitrogen transformation, waterlogged soil, nitrification, denitrification, volatilization