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Nitrous oxide (N2O) is an important long-lived greenhouse gas and is a dominant contributor to stratospheric ozone depletion. Mitigating N2O emission from the rice paddies is one of the important challenges to global food security and climate change research while sustaining optimum productivity. We conducted a 2-year experiment to investigate the effect of different plant growth regulators (PGRs) on N2O emission to the atmosphere. The PGRs namely abscisic acid and cytozyme (20 mg L−1), kinetin (10 and 20 mg L−1) and tea extract (1:20 w/w) along with distilled water as control were sprayed at the tillering and panicle initiation stages of rice crop. Abscisic acid and kinetin (10 and 20 mg L−1) were found to bring about a significant (p

Identification of the combination of tillage and N fertilization practices that reduce agricultural Nitrous oxide (N2O) emissions while maintaining productivity is strongly required in the Indian s...

Agricultural soil acts as a source and sink of important greenhouse gases (GHGs) like methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2). Rice paddies have been a major concern to scientific community, because they produce the threatening and long-lasting GHGs mainly CH4 and N2O. Around 30% and 11% of global agricultural CH4 and N2O, respectively, emitted from rice fields. Thus, it is urgent to concurrently quantify the fluxes of CH4 and N2O to improve understanding of both the gases from rice fields and to develop mitigation strategies for upcoming climate change reduction. An effort is being made in this review to discuss exclusively the emission of CH4 and N2O under normal and controlled conditions in different locations of India and also addresses the current synthesis of available data on how field and crop management activities influence CH4 and N2O emissions in rice fields. Making changes to conventional crop management regimes could have a significant impact on reducing GHG emissions from rice field. Environmental and agricultural factors related to soil could be easily altered by management practices. So, knowing the mechanism of CH4 and N2O production and release in the rice field and factors controlling the emissions is fundamental to develop well-organized strategies to reduce emissions from rice cultivated soil. This will help the regulatory bodies or policy makers to formulate adequate policies for agricultural farmers to refine the GHG emissions as well as minimize the global climate change.

The excessive use of synthetic nitrogen fertilizer in agriculture interferes in natural ecosystem functioning and pollutes the environment through nitrogen leaching, volatilization, nitrification, and denitrification. The consumption of conventional fertilizer in the agricultural field has increased nitrous oxide (N2O) emission, an important trace gas, which is responsible for stratospheric ozone layer depletion and global warming. Alternatively, the use of slow-release fertilizer (SRF) is considered to ameliorate crop nitrogen use efficiency (NUE) and yields while minimizing problems related to environment caused by inorganic N-fertilizer. For SRF, the coating of urea particles can be done with various coating materials; thus, nutrients release slowly from coated fertilizer and plant can efficiently use it. The degree of N release to soil depends on the coating material being used. Starch is one type of encapsulating polymer which can be used to coat or encapsulate the urea granules to slow the rate of fertilizer release. Although starch is mineralizable, the addition of different cross-linking agents reduces the release rate of entrapped urea from their cross-linking structure. The presence of coating directly retards the ammonium (NH4+) oxidation by reducing the activity of nitrifying bacteria and indirectly reduces the substrate availability for denitrification in soil. In this chapter, we have briefly reviewed about the different types of SRF and its use in the different agroecosystems. The efficiency of SRF for the reduction of greenhouse gas from rice and wheat ecosystems, mainly N2O emission by affecting nitrification and denitrification process in soil, has also been discussed.

Global climate change is one of the most prominent and complex environmental problems caused by increasing concentrations of atmospheric greenhouse gases. Rice paddies are an important anthropogenic source of nitrous oxide (N2O), a greenhouse gas approximately 298 times stronger than carbon dioxide. Identifying a suitable mitigation method for N2O emissions from rice agriculture, while maintaining optimum crop productivity is strongly needed. A 2-year field study was conducted on rice to assess N2O emissions in response to the application of different plant growth regulators (PGRs). The PGRs abscisic acid (ABA) and cytozyme (20 mg L−1), kinetin (10 and 20 mg L−1) and wet tea extract (1:20 w/w) along with distilled water as control were sprayed at the tillering and panicle initiation stages of rice. Compared with control treatment, exogenously applied ABA and kinetin (10 and 20 mg L−1) significantly (p

Agricultural soils are an important source of greenhouse gas nitrous oxide (N

We investigated nitrous oxide (N2O) emission from an irrigated rice field over two years to evaluate the management of nitrogenous fertiliser and its effect on reducing emissions. Four forms of nitrogenous fertilisers: NPK at the recommended application rate, starch–urea matrix (SUM) + PK, neem-coated urea + PK and urea alone (urea without coating) were used. Gas samples were collected from the field at weekly intervals with the static chamber technique. N2O emissions from different treatments ranged from 11.58 to 215.81 N2O-N μg/m2/h, and seasonal N2O emissions from 2.83 to 3.89 kg N2O-N/ha. Compared with other fertilisers, N2O emissions were greatest after the application of the conventional NPK fertiliser. Moreover, SUM + PK reduced total N2O emissions by 22.33% (P

Agricultural soils are the major source of global nitrous oxide (N

Nitrous oxide is a greenhouse gas with high global warming potential emitted from agricultural sources. The effects of tillage practices and different levels of N fertiliser on seasonal fluxes of N2O were investigated in a field planted with the wheat variety Sonalika. The experiment was conducted during 2012–13 and 2013–14 under conventional tillage (CT) and reduced tillage (RT) farming systems in combination with four different levels of nitrogen fertiliser (i.e. zero nitrogen (F1), 60kgNha–1 (F2), 80kgNha–1 (F3) and 100kgNha–1 (F4)). Both tillage practices and fertiliser significantly (P