Conservation Agriculture Approaches for Reducing Carbon Footprints

Abstract

Intensive soil tillage, burning of crop residues and over use of fertilizer and irrigation water under current agricultural practices has accelerated the pace of degradation in Indian agriculture. Intensive soil tillage increases soil erosion and nutrient runoff into nearby waterways. Crop residue burning resulting in loss of plant nutrients and release of greenhouse gases (GHGs) in the atmosphere. Imbalanced use of chemical fertilizer leads to soil compaction, slows down the fertilizer utilization rate and contaminates the local environment. Increasing demand of irrigation water causes water shortage and harms the environment in several ways including increased salinity, nutrient pollution, and the degradation of flood plains and wetlands. In the face of these management and environmental challenges, there is a need to formulate such agricultural practices which improve the productivity of natural resources as well as of external inputs and help to prevent soil degradation. Conservation agriculture (CA) practices such as reduced tillage, residue retention and proper crop rotations offer such solutions. CA also helps in making agricultural systems more resilient to climate change and safeguard ecosystem services.

In this chapter, five key farming strategies that are proven to be effective in increasing crop production while lowering carbon footprint is discussed. It includes -- (i) use of reduced tillage in combination with crop residue retention and decomposition to increase soil organic carbon; (ii) reduction in use of inorganic fertilizer and improvement of nitrogen (N) fertilizer use efficiency including N2- fixing pulses in rotations to lower the carbon footprints of field crops as N fertilizer contribute about 35 to 50% of the total emissions; (iii) use of diversified cropping systems and adopting intensified rotation with reduced summer fallow for lowering the carbon footprint by as much as 150 %; (iv) integration of key cropping practices which can increase crop yield (15 to 60 %), reduce emissions (25 to 50 %), and lower the carbon footprint of cereal crops (25 to 35 %), and (v) enhancing soil carbon sequestration as the emissions from crop inputs can be partly offset by carbon conversion from atmospheric CO2 into plant biomass and ultimately sequestered into the soil. With the adoption of these improved conservation agriculture technology, one can optimize the system performance while reducing the carbon footprint of crop cultivation.