[Objective] This study aimed to investigate the effect of soil organic carbon mineralization at different temperature on the amount of nitrogen application, in order to provide references for the establishment of carb...[Objective] This study aimed to investigate the effect of soil organic carbon mineralization at different temperature on the amount of nitrogen application, in order to provide references for the establishment of carbon circulation model for orchard eco-system. [Method] The effects of nitrogen treatments on soil organic carbon mineralization of citrus orchard soil were investigated under 10, 20, 30 ℃ by laboratory simulated experiment. [Result] The mineralization rate decreased quickly at the be- ginning of the experiment but remained stable at the late period under three temper- ature treatments. The amounts of CO2 ranged from 1 328.25-2 219.42 mg/kg under three temperature condition, and the amount of soil organic carbon mineralization of 100 mg/kg （N4） treatment was the greatest, while that of CK was the lowest. High level nitrogen treatment （N4 and N3） were significant higher than the lower level nitro- gen treatment （N2 and N1）. The soil organic carbon mineralization rate increased with the temperature from 10 to 30℃. The dependence of soil carbon mineralization to temperature （Q10） was different under different nitrogen treatments that the Qlo value of N2 treatment was the lowest while that of the N4 treatment was the greatest. The soil organic carbon mineralization in Citrus orange orchard soil was affected significantly by high level nitrogen treatment, but with no significance under lower nitrogen treatment. [Conclusion] The dependence of soil carbon mineralization to temperature （Q10） increased with the increasing nitrogen input. The combination of nitrogen with temperature may increase the CO2 emission from Citrus orchard soil.展开更多
Fruit flies are causing extensive socio-economic losses in citrus orchards in Ghana. The flies as quarantine pests have detrimental effects on the export market due to international trade regulations. Oecophylla speci...Fruit flies are causing extensive socio-economic losses in citrus orchards in Ghana. The flies as quarantine pests have detrimental effects on the export market due to international trade regulations. Oecophylla species have been tested as biological control agents on other crops, and have shown great potential in reducing the effects of pests. The effectiveness of Oecophylla as a biocontrol agent of fruit flies was compared with insecticide, Cypermethrin ＋ Dimethoate （Cydim super~） at Forest and Horticultural Crops Research Centre, Kade, in the Eastern Region of Ghana. The results have shown that trees colonized by Oecophylla had between 6%-10% fly infestation and Cypermethrin ＋ Dimethoate （1614 mg a.i. mL~ tree＂1） recorded 3.0% infestation. Cypermethrin ＋ Dimethoate treatment recorded 3.50 ~ 0.87 dropped fruits, and Oecophylla colonized-trees recorded 15 to 19.20 -4- 3.61. Oecophylla colonized-trees recorded yield values from 12.90 to 15.20 tons ha-~ whilst Cypermethrin ＋ Dimethoate treatment recorded 27.90 tons hat fruit yield. Total number of fly landings in the presence of Oecophylla （72.00） was significantly lower than the absence of Oecophylla （114.20）. Set-up with no Oecophylla recorded the highest infestation index （71.17） while the presence recorded 45.83. These results suggest that Oecophylla longinoda can be used as a biocontrol agent for IPM programs in citrus orchards.展开更多
Studies related to the quantitation and distribution of soil organic carbon （C） under different land use types can help to fill the knowledge gaps regarding estimation of the amount of C stored in soils at a global ...Studies related to the quantitation and distribution of soil organic carbon （C） under different land use types can help to fill the knowledge gaps regarding estimation of the amount of C stored in soils at a global scale. Orchards are an important land use type in southern China; the total area （1.15 x 107 ha） of orchards in China comprises approximately 20.5% of the area of all orchards worldwide. We assessed soil organic C stocks （SOCS） in citrus orchards in Yongchun County （consisting of 22 towns）, Fujian Province, China in 1982 and 2010. The southeastern part of the county, an area featuring extensive citrus farming with a gently sloping landscape and low rates of water erosion, had the highest SOCS. In contrast, the lowest SCOS was observed in the northern part of the county, where steep hills with severe erosion problems are common and citrus orchards are sparsely distributed. From 1982 to 2010, the mean SOCS in citrus orchards increased from 22.1 to 41.7 Mg ha-1 which indicated that current management practices such as fertilization, irrigation, and cultivation enhanced soil C stocks. Further in-depth studies on the effects of these practices on C sequestration would be worthwhile and surveys of SOCS throughout Fujian Province are needed, to support efforts to mitigate global C emission.展开更多
基金Supported by the National Key Technology R&D Program(2012BAD14B15)the Fund for Scientific and Technological Innovation Team Construction of the Fujian Academy of Agricultural Sciences(STIF-Y01)the Inovation Fund for Youth Talent of Fujian Academy of Agricultural Sciences(2010QA-1)~~
文摘[Objective] This study aimed to investigate the effect of soil organic carbon mineralization at different temperature on the amount of nitrogen application, in order to provide references for the establishment of carbon circulation model for orchard eco-system. [Method] The effects of nitrogen treatments on soil organic carbon mineralization of citrus orchard soil were investigated under 10, 20, 30 ℃ by laboratory simulated experiment. [Result] The mineralization rate decreased quickly at the be- ginning of the experiment but remained stable at the late period under three temper- ature treatments. The amounts of CO2 ranged from 1 328.25-2 219.42 mg/kg under three temperature condition, and the amount of soil organic carbon mineralization of 100 mg/kg （N4） treatment was the greatest, while that of CK was the lowest. High level nitrogen treatment （N4 and N3） were significant higher than the lower level nitro- gen treatment （N2 and N1）. The soil organic carbon mineralization rate increased with the temperature from 10 to 30℃. The dependence of soil carbon mineralization to temperature （Q10） was different under different nitrogen treatments that the Qlo value of N2 treatment was the lowest while that of the N4 treatment was the greatest. The soil organic carbon mineralization in Citrus orange orchard soil was affected significantly by high level nitrogen treatment, but with no significance under lower nitrogen treatment. [Conclusion] The dependence of soil carbon mineralization to temperature （Q10） increased with the increasing nitrogen input. The combination of nitrogen with temperature may increase the CO2 emission from Citrus orchard soil.
文摘Fruit flies are causing extensive socio-economic losses in citrus orchards in Ghana. The flies as quarantine pests have detrimental effects on the export market due to international trade regulations. Oecophylla species have been tested as biological control agents on other crops, and have shown great potential in reducing the effects of pests. The effectiveness of Oecophylla as a biocontrol agent of fruit flies was compared with insecticide, Cypermethrin ＋ Dimethoate （Cydim super~） at Forest and Horticultural Crops Research Centre, Kade, in the Eastern Region of Ghana. The results have shown that trees colonized by Oecophylla had between 6%-10% fly infestation and Cypermethrin ＋ Dimethoate （1614 mg a.i. mL~ tree＂1） recorded 3.0% infestation. Cypermethrin ＋ Dimethoate treatment recorded 3.50 ~ 0.87 dropped fruits, and Oecophylla colonized-trees recorded 15 to 19.20 -4- 3.61. Oecophylla colonized-trees recorded yield values from 12.90 to 15.20 tons ha-~ whilst Cypermethrin ＋ Dimethoate treatment recorded 27.90 tons hat fruit yield. Total number of fly landings in the presence of Oecophylla （72.00） was significantly lower than the absence of Oecophylla （114.20）. Set-up with no Oecophylla recorded the highest infestation index （71.17） while the presence recorded 45.83. These results suggest that Oecophylla longinoda can be used as a biocontrol agent for IPM programs in citrus orchards.
基金supported by the National Key Technology R&D Program of China (No.2012BAD14B15)
文摘Studies related to the quantitation and distribution of soil organic carbon （C） under different land use types can help to fill the knowledge gaps regarding estimation of the amount of C stored in soils at a global scale. Orchards are an important land use type in southern China; the total area （1.15 x 107 ha） of orchards in China comprises approximately 20.5% of the area of all orchards worldwide. We assessed soil organic C stocks （SOCS） in citrus orchards in Yongchun County （consisting of 22 towns）, Fujian Province, China in 1982 and 2010. The southeastern part of the county, an area featuring extensive citrus farming with a gently sloping landscape and low rates of water erosion, had the highest SOCS. In contrast, the lowest SCOS was observed in the northern part of the county, where steep hills with severe erosion problems are common and citrus orchards are sparsely distributed. From 1982 to 2010, the mean SOCS in citrus orchards increased from 22.1 to 41.7 Mg ha-1 which indicated that current management practices such as fertilization, irrigation, and cultivation enhanced soil C stocks. Further in-depth studies on the effects of these practices on C sequestration would be worthwhile and surveys of SOCS throughout Fujian Province are needed, to support efforts to mitigate global C emission.
