Carbon Footprint and Sustainability of Agricultural Production Systems in India

The agriculture sector, which accounts for about 52% of the total workforce despite a steady decline of its share in the gross domestic product (GDP), is still the largest economic sector that plays a significant role in the overall socio-economic development of India. Sustainability of agricultural production systems depends on their carbon (C) footprint and the C output-input ratio. Thus, the present study was conducted with the objectives to: (i) assess C emissions in relation to predominant agricultural systems in India; (ii) evaluate C-use efficiency of production systems; and (iii) determine the relative sustainability of agronomic production systems as determined by their C footprints. The data collated on C-based input into the soil for predominant agricultural and horticultural crops included the amounts of fertilizers (N, P, K), herbicides, and pesticides used for crops annually, cropland area, total production of each crop, water-management practices, energy used for different operations, and total number of livestock. These data were used to compute C equivalent (Ce) per hectare of input and output, and the relative sustainability indices as a measure of the C-production efficiency. Beginning with low C-based input of 69.7 Tg Ce/yr (1 Tg = teragram = 10(12)g = 1 million ton) in 1960-61, input of fertilizers, pesticides, farm power, feed, fodder, and electricity increased to 281.2 Tg Ce/yr by 2008-09. The output in agriculture increased from 578.6 Tg Ce/yr in 1960-61 to 1239.1 Tg Ce/yr in 2008-09. The C-sustainability index was high in 1960, and was indicative of the minimum usage of inputs prior to the onset of the Green Revolution. Thereafter, the C-sustainability index decreased during 1970s and 1980s because of increased C-based inputs. There existed a linear relationship between C input and C output, indicating that an increase of 1 Tg Ce/yr of C input resulted in a corresponding increase in C output of similar to 21 Tg Ce/yr. Total food grain production in India increased from 89 million ton in 1960-61 to 262 million ton in 2008-09.