Trend of fertility status of Indian soils

There is an increasing concern about the sustainability of Indian agriculture because of deterioration in soil fertility. The data from soil testing laboratories and published literature were analyzed to determine the trend in fertility status of agricultural soils of India since 1967, when the Green Revolution set in. Based on the soil test values of N, P and K, soil samples were classified into three categories i.e., low, medium and high, and nutrient index was calculated for soils of different states. In some states like for example, West Bengal, Gujarat, Tamil Nadu, N fertility increased, while it declined in Orissa and Kerala. In the remaining states the nitrogen fertility status remained almost same from 1967 to 1997. An increasing trend in P status of soil was observed in Assam, Karnataka and Kerala. In the rest of the states it remained unchanged. Potassium fertility either remained same or decreased. Available information indicated that the soil organic carbon content either remained static or increased in certain regions of India. Therefore, contrary to the general perception, there has not been much depletion of soil fertility of agricultural soils of the country over the years. Detailed data on time series are required to ascertain the trend in fertility of Indian soil.