Temporal changes of IARI farm soils under mechanized and intensive cultivation

Six soil series of Indian Agricultural Research Institute (IARI) farm have been studied to detect the temporal changes over last twenty-six years due to intensive farming practices. A number of profiles were studied in the location of each soil series from which six representative pedons were selected and studied in details in respect of various morphological and physico-chemical characteristics. Such temporal observations over the spatial distribution indicated that the sub surface soil colour of Palam and Daryapur series has changed from yellowish brown to dark yellowish brown and soil colour of Jagat series has got darkened throughout the profile. There has been leaching of finer particles from surface to sub-surface horizons in Daryapur soil series leading to' development of Bwhorizon. Soils of Daryapur and Nagar series have been classified as Inceptisols instead of Entisols as classified earlier on the basis of structural development in sub-surface horizon. The soils of Mehrauli, Jagat and Holambi, which were non-calcareous in nature, are in the process of becoming calcareous. The organic carbon status in all soil series except Holambi and Daryapur series has declined over the period. Increase in bulk density has been observed in Mehrauli, Palam and Holambi soil series.