title: Carbon dioxide emission in relation with irrigation and organic amendments from a sweet corn field.
abstract: Soil moisture and organic matter level affects soil respiration and microbial activities, which in turn impact greenhouse gas (GHG) emissions. This study was conducted to evaluate the effect of irrigation levels (75% [deficit], 100% [full], and 125% [excess] of reference crop evapotranspiration requirements), and organic amendments (OA) type (chicken manure [CM] and bone meal [BM]) and OA application rates (0,168, 336 and 672 kg total N ha-1) on (i) soil physical properties (bulk density, organic matter content and soil moisture content) and (ii) soil carbon dioxide (CO2) emissions from a highly weathered tropical Hawai'ian soil. Carbon dioxide readings were consistently taken once or twice a week for the duration of the cropping season. A drip irrigation system was used to apply the appropriate amount of irrigation water to the treatment plots. Treatments were randomly selected and corresponding organic amendments were manually incorporated into the soil. Plots were cultivated with sweet corn (Zea mays 'SS-16'). Soil moisture content within and below the rootzone was monitored using a TDR 300 soil moisture sensor (Spectrum Technologies, Inc., Plainfield, IL, USA) connected with 12 cm long prongs. Soil bulk density and organic matter content were determined at the end of the cropping season. Analysis of variance results revealed that OA type, rate, and their interaction had significant effect on soil CO2flux (P < 0.05). Among the OA rates, all CM mostly resulted in significantly higher soil CO2fluxes compared to BM and control treatment (p < 0.05). The two highest rates of BM treatment were not significantly different from the control with regard to soil CO2flux. In addition, organic amendments affected soil moisture dynamics during the crop growing season and organic matter content measured after the crop harvest. While additional studies are needed to further investigate the effect of irrigation levels on soil CO2flux, it is recommended that in order to minimize soil CO2emissions, BM soil amendments could be a potential option to reduce soil CO2fluxes from agricultural fields similar to the one used in this study.
authors.affiliation: a College of Agriculture and Humans Sciences, Prairie View A&M University , Prairie View , Texas , USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Fares
authors.affiliation: b College of Tropical Agriculture and Human Sciences, University of Hawaii-Manoa , Manoa , Hawaii , USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Bensley
authors.affiliation: a College of Agriculture and Humans Sciences, Prairie View A&M University , Prairie View , Texas , USA.
authors.forename: Haimanote
authors.initials: H
authors.lastname: Bayabil
authors.affiliation: a College of Agriculture and Humans Sciences, Prairie View A&M University , Prairie View , Texas , USA.
authors.forename: Ripendra
authors.initials: R
authors.lastname: Awal
authors.affiliation: c Special Collections/Archives Department- John B. Coleman Library, Prairie View A&M University, Prairie View , Texas , USA.
authors.forename: Samira
authors.initials: S
authors.lastname: Fares
authors.affiliation: b College of Tropical Agriculture and Human Sciences, University of Hawaii-Manoa , Manoa , Hawaii , USA.
authors.forename: Hector
authors.initials: H
authors.lastname: Valenzuela
authors.affiliation: d Department of Environmental Sciences and Engineering , Government College University , Faisalabad , Pakistan.
authors.forename: Farhat
authors.initials: F
authors.lastname: Abbas
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods*; D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis*; D002645:Chickens; D006254:Hawaii; D008372:Manure; D058871:Organic Agriculture / Q000379:methods*; D018526:Plant Transpiration; D012621:Seasons; D012987:Soil / Q000737:chemistry; D014867:Water; D003313:Zea mays / Q000502:physiology*
chemical_list: D008372:Manure; D012987:Soil; D014867:Water; D002245:Carbon Dioxide
keywords: Bone meal; Hawai'i; carbon dioxide; chicken manure; greenhouse gas