Carbon footprint and water footprint of rice and wheat production in Punjab, India

Carbon footprint and water footprint assessments can be powerful tools to guide sustainable food production systems. The present study simultaneously quantified the carbon footprint (CF) and water footprint (WF) of rice and wheat production in the five agro-climatic zones of Punjab, India using farm survey data. Further, the variability in CF among the five agro-climatic zones and farm sizes was analysed. The carbon footprint per unit area of rice and wheat was found to be 8.80 +/- 5.71 and 4.18 +/- 1.13 t CO(2)eq/ha respectively. The CF per tonne of rice and wheat was 1.20 +/- 0.70 and 0.83 +/- 0.23 t CO(2)eq/t respectively. Large farms had 39% lower CF per tonne of rice compared to small farms. Residue burning, direct methane emissions and fertilizer use were the most important factors that contributed to the CF of rice and wheat production in Punjab. Nitrogen fertilizer use was identified as the major hotspot for mitigation. The average WF of rice and wheat was found to be 1097 and 871 m(3)/t respectively. A disparity between CROPWAT estimates of blue WF and actual blue water use was established indicating the need for actual blue WF accounting, particularly for flood irrigated crop production. Additionally, policy measures based on ground situation are discussed and the major role of local government policies in mitigating carbon and water footprint is highlighted.

Automated summary

This study quantified the carbon and water footprints of rice and wheat production in five agro-climatic zones of Punjab, India, revealing that rice and wheat had respective carbon footprints of 8.80 and 4.18 t CO(2)eq/ha. Nitrogen fertilizer use was identified as a major hotspot for carbon footprint mitigation, with large farms having lower carbon footprints per tonne compared to small farms.