title: Greenhouse gas mitigation in rice-wheat system with leaf color chart-based urea application.
abstract: 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%.
authors.affiliation: Division of Environmental Sciences, Indian Agricultural Research Institute, New Delhi, 110012, India. artibhatia.iari@gmail.com
authors.forename: Arti
authors.initials: A
authors.lastname: Bhatia
authors.forename: Himanshu
authors.initials: H
authors.lastname: Pathak
authors.forename: Niveta
authors.initials: N
authors.lastname: Jain
authors.forename: Pawan K
authors.initials: PK
authors.lastname: Singh
authors.forename: Ritu
authors.initials: R
authors.lastname: Tomer
mesh_terms: D000383:Agriculture; D000397:Air Pollution / Q000517:prevention & control*; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods*; D057232:Global Warming / Q000517:prevention & control; D017752:Greenhouse Effect / Q000517:prevention & control; D008697:Methane / Q000032:analysis / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D058458:Nitrogen Cycle; D009585:Nitrogen Dioxide / Q000032:analysis / Q000378:metabolism; D009609:Nitrous Oxide / Q000032:analysis / Q000378:metabolism; D012275:Oryza / Q000254:growth & development* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D014908:Triticum / Q000254:growth & development* / Q000378:metabolism; D014508:Urea / Q000737:chemistry*
chemical_list: D002245:Carbon Dioxide; D014508:Urea; D009609:Nitrous Oxide; D009584:Nitrogen; D008697:Methane; D009585:Nitrogen Dioxide