Greenhouse gas mitigation in rice–wheat system with leaf color chart-based urea application

• Published in: Environmental monitoring and assessment 2012-05, Vol.184 (5), p.3095-3107
• Main Authors: Bhatia, Arti, Pathak, Himanshu, Jain, Niveta, Singh, Pawan K., Tomer, Ritu
• Format: Article
• Language: English
• Subjects: Agricultural research; Agriculture; Air Pollution - prevention & control; Atmospheric Protection/Air Quality Control/Air Pollution; Carbon dioxide; Carbon Dioxide - analysis; Carbon Dioxide - metabolism; Carbon dioxide emissions; Climate change; Color; Earth and Environmental Science; Ecology; Ecotoxicology; Efficiency; Emissions control; Environment; Environmental impact; Environmental Management; Environmental monitoring; Environmental Monitoring - methods; Experiments; Fertilizers; Global warming; Global Warming - prevention & control; Greenhouse effect; Greenhouse Effect - prevention & control; Greenhouse gases; Methane; Methane - analysis; Methane - metabolism; Monitoring/Environmental Analysis; Nitrogen - metabolism; Nitrogen Cycle; Nitrogen Dioxide - analysis; Nitrogen Dioxide - metabolism; Nitrous oxide; Nitrous Oxide - analysis; Nitrous Oxide - metabolism; Oryza - growth & development; Oryza - metabolism; Oryza sativa; Plant Leaves - chemistry; Plant Leaves - metabolism; Research centers; Rice; Studies; Triticum - growth & development; Triticum - metabolism; Urea; Urea - chemistry; Wheat
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-011-2174-8

Conventional blanket application of nitrogen (N) fertilizer results in more loss of N from soil system and emission of nitrous oxide, a greenhouse gas (GHG). The leaf color chart (LCC) can be used for real-time N management and synchronizing N application with crop demand to reduce GHG emission. A 1-year study was carried out to evaluate the impact of conventional and LCC-based urea application on emission of nitrous oxide, methane, and carbon dioxide in a rice–wheat system of the Indo-Gangetic Plains of India. Treatments consisted of LCC scores of ≤4 and 5 for rice and wheat and were compared with conventional fixed-time N splitting schedule. The LCC-based urea application reduced nitrous oxide emission in rice and wheat. Application of 120 kg N per hectare at LCC ≤ 4 decreased nitrous oxide emission by 16% and methane by 11% over the conventional split application of urea in rice. However, application of N at LCC ≤ 5 increased nitrous oxide emission by 11% over the LCC ≤ 4 treatment in rice. Wheat reduction of nitrous oxide at LCC ≤ 4 was 18% as compared to the conventional method. Application of LCC-based N did not affect carbon dioxide emission from soil in rice and wheat. The global warming potential (GWP) were 12,395 and 13,692 kg CO 2  ha −1 in LCC ≤ 4 and conventional urea application, respectively. Total carbon fixed in conventional urea application in rice–wheat system was 4.89 Mg C ha −1 and it increased to 5.54 Mg C ha −1 in LCC-based urea application (LCC ≤ 4). The study showed that LCC-based urea application can reduce GWP of a rice–wheat system by 10.5%.