Not AvailableCarbon content in soils changes depending on the land use system, type of management practice and time.
There is an increasing concern about the soil quality vis-à-vis organic carbon content in soils due to global
warming and enhanced CO2 concentration in the atmosphere. This has led to estimate carbon stock in soils
at global and regional levels. The objective of the present study was to evaluate RothC model to estimate
total organic carbon (TOC) changes under four long term fertilizer experimental sites representing subhumid
moist (Sarol and Nabibagh), sub-humid dry (Panjri) and semi-arid (Teligi) climate in India. The
plant carbon input rate was calibrated using organic carbon and other soil parameters using RothC. The
results showed that RothC could simulate changes in TOC in two contrasting eco-sites for surface soil
layers. The root mean square error (RMSE) considered as modelling error ranged from 11.50 to 15.01,
4.70 to 11.60, 2.14 to 6.52 and 1.45 to 13.74 in the surface layers of Sarol, Nabibagh, Panjri, and Teligi
sites, respectively. The simulation biases expressed by M (relative error) by Student‘t’ value for all the
treatments at these sites were non-significant with two exceptions. Observed trends in TOC consist of an
increase for all the four treatments in the sub-humid site of Sarol and Nabibagh; while manures alone
or in combination increase TOC appreciably in Teligi and Panjri. TOC remained, however, almost similar
over years for the control (no fertilizer or manure) and NPK treatments in all the four sites. Analysis of
RothC output data showed that this model could be used as a tool to arrive at different threshold values of
rainfall to influence decomposition rate modifier and thus to find out rate of organic carbon sequestration
in various bioclimatic systems.Not Availabl
