Abstract:
The soil organic carbon (SOC) pool is the key indicator of soil health and quality
which in turn plays a vital role to soil sustainability. carbon sequestration is the
process of storing carbon in carbon pool. which occur through biological ,chemical
and physical process. This changes accelerated by changes in land use and
agricultural practices and also specially by microorganisms. This paper reviews the
current knowledge of microbial processes affecting C sequestration in
agroecosystems. The microbial contribution to soil C storage is directly related to
microbial community dynamics and the balance the balance between formation and
degradation of microbial byproducts. Soil microbes also indirectly influence C
cycling by improving soil aggregation, which physically protects soil organic matter
(SOM). Crop rotations ,reduced or no-tillage practices, organic farming. and cover
crops increase total microbial biomass enhancing the accumulation of MOM. A
quantitative and qualitative improvement of SOM is generally observed in agro
ecosystems favoring a fungal-dominated community. ln the present review we focus
on the greenhouse gas
C02 with relevance to its effect on plant associated beneficial
and pathogenic microorganisms in terrestrial ecosystems. Role of these
microorganisms in belowground nutrient cycling and soil aggregation is discussed
with reference to soil C-sequestration This review demonstrates that eC02 influence
the richness, composition and structure of soil microbial community and the
influence is more on active microbial communities and in the vicinity of roots. High
C:N ratio under co2 favors fungi with wider C:N ratio and nutrient acquisition ability
and biological nitrogen fixers. The ecosystems with fungal-dominated soil
communities may have higher C retention than bacterial dominated soil
communities. However, soil C-sequestration through plant growth. is strongly
controlled by availability of nitrogen and nutrients required for biological nitrogen
fixation. Nitrogenous and other chemical fertilizers show positive effect on C-sequestration but carry a carbon cost. Promotion of biological nitrogen fixers. and
nutrient solubilizers and mobilizers may help in maintaining soil nutrient balance for
higher C -sequestration
