The Ecological Footprint is one of the world's most universal measures of ecological sustainability. Ecological Footprints measure the area of the Earth's surface needed to sustain our consumption patterns and assimilate our wastes.
Land footprint: is the amount of cropland needed to produce a given quantity of crop taking into consideration differences in productivity of cropland in various regions and long term impacts on soil resources from various growing methods.
Water footprint: measures the acre-feet of irrigation water needed to grow crops and the amount of water needed to dilute toxic concentrations of chemicals to safe levels.
Carbon footprint: measures the area needed to sequester carbon emissions associated with planting, maintaining, and harvesting, irrigation, production of chemical inputs, and disposal of wastes.
So naturally the Chemical Free Self-Sustainable Farming methods have reduced foot-prints for the same crop grown in conventional method, applying Chemical fertilizers.