Soil Carbon Dynamics Under Changing Climate A Research Transition from Absolute to Relative Roles of Inorganic Nitrogen Pools and Associated Microbial Processes:A Review

It is globally accepted that soil carbon （C） dynamics are at the core of interlinked environmental problems, deteriorating soil quality and changing climate. Its management remains a complex enigma for the scientific community due to its intricate relationship with soil nitrogen （N） availability and moisture-temperature interactions. This article reviews the management aspects of soil C dynamics in light of recent advances, particularly in relation to the availability of inorganic N pools and associated microbial processes under changing climate. Globally, drastic alterations in soil C dynamics under changing land use and management practices have been primarily attributed to the variation in soil N availability, resulting in a higher decomposition rate and a considerable decline in soil organic C （SOC） levels due to increased soil CO2 emissions, degraded soil quality, and increased atmospheric CO2 concentrations, leading to climate warming. Predicted climate warming is proposed to enhance SOC decomposition, which may further increase soil N availability, leading to higher soil CO2 effiux. However, a literature survey revealed that soil may also act as a potential C sink, if we could manage soil inorganic N pools and link microbial processes properly. Studies also indicated that the relative, rather than the absolute, availability of inorganic N pools might be of key importance under changing climate, as these N pools are variably affected by moisture-temperature interactions, and they have variable impacts on SOC turnover. Therefore, multi-factorial studies are required to understand how the relative availability of inorganic N pools and associated microbial processes may determine SOC dynamics for improved soil C management.

Compatible package-based agriculture systems:an urgent need for agro-ecological balance and climate change adaptation

Besides contributing majorly in the growth of a country,agriculture is one of the severely affected sectors at present.Several modifications and adaptations are being made in agricultural practices to cope-up with the declining soil fertility and changing climate scenarios across the world.However,the development and adoption of a single agricultural practice may not help in the holistic mitigation of the impacts of climate change and may result in economic vulnerability to farmers.Therefore,it is high time to develop and recommend a group of agricultural practices i.e.,package-based agriculture system having some compatibility for one another in the long term.In this article,a viewpoint has been given on some emergent agronomic practices adopted in the tropical agroecosystems which have potential to be developed as compatible agricultural package in combination.Moreover,we also emphasized on exploring some key indicators/environmental factors to assess the compatibility of different agronomic practices.For identifying the research transition from single to combined agricultural practices,a bibliometric analysis was performed by using conservation agriculture(CA),the system of rice intensification(SRI),organic agriculture and soil(biochar)amendment as the major agronomic practices being used for improving agroecological services such as improving nutrient cycling,soil fertility and crop productivity as well as climate change mitigation.The results revealed that scientific communities are now paying attention to exploring the role of combined agricultural practices for agro-ecological balance and climate change adaptation.Moreover,the limitations of the adoption of agronomic packages under different agro-climatic zones have also been highlighted.The recommendations of the study would further help the environmental decision-makers to develop potential measures for climate change mitigation without compromising the agro-ecological balance.