The effects of nitrogen fertilization on N2O emissions from a rubber plantation.

To gain the effects of N fertilizer applications on N2O emissions and local climate change in fertilized rubber (Hevea brasiliensis) plantations in the tropics, we measured N2O fluxes from fertilized (75 kg N ha(-1) yr(-1)) and unfertilized rubber plantations at Xishuangbanna in southwest China over a 2-year period. The N2O emissions from the fertilized and unfertilized plots were 4.0 and 2.

[Characteristics of N2, N2O, NO, CO2 and CH4 Emissions in Anaerobic Condition from Sandy Loam Paddy Soil].

Understanding the characteristics of the production of nitrogen gases (N2, N2O and NO), CO2 and CH4 in anaerobic paddy soils is not only a prerequisite for an improved mechanistic understanding of key microbial processes involved in the production of atmospheric greenhouse gases (GHG), but might also provide the basis for designing greenhouse gas mitigation strategies. Moreover, quantifying the composition fractions of denitrification gaseous products is of key importance for improving parameterization schemes of microbial processes in process-oriented models which are increasingly used for assessing soil GHG emissions at site and national scales. In our experiments we investigated two sandy loam soils from two paddy fields.

[Effect of carbon substrate concentration on N2, N2O, NO, CO2, and CH4 emissions from a paddy soil in anaerobic condition].

Understanding the effects of carbon and nitrogen substrates concentrations on the emissions of denitrification gases including nitrogen (N2) , nitrous oxide (N2O) and nitric oxide (NO), carbon dioxide (CO2) and methane (CH4) from anaerobic paddy soils is believed to be helpful for development of greenhouse gas mitigation strategies. Moreover, understanding the quantitative dependence of denitrification products compositions on carbon substrate concentration could provide some key parameters or parameterization scheme for developing process-oriented model(s) of nitrogen transformation. Using a silt loam soil collected from a paddy field, we investigated the influence of carbon substrate concentration on the emissions of the denitrification gases, CO2 and CH4 from anaerobically incubated soils by setting two treatments: control (CK) with initial soil nitrate and dissolved organic carbon (DOC) concentrations of ~ 50 mg.

[N2O emission from rice-rapeseed rotation system in Chengdu Plain of Sichun Basin].

By using static chamber/gas chromatograph techniques, the N2O emission from rice-rapeseed rotation system in Chengdu Plain of Sichuan Basin was measured from June 2005 to June 2006, with its characteristics and affecting factors investigated. The results showed that the total emission of N2O in a rotation cycle was (8.3 +/- 2.

[Estimation of chemical fertilizer N-induced direct N2O emission from China agricultural fields in 1991-2000 based on GIS technology].

Referring to the definition of agricultural field N2O emission factor by the Intergovernmental Panel on Climate Change, the main controlling factors climate and cropping system were introduced to estimate the chemical fertilizer N-induced direct N2O emission from China agricultural fields in 1991-2000, and a spatial inventory with 10 km x 10 km resolution was developed by dint of GIS framework. The results indicated that there was an increasing trend in the annual direct N2O emission, due to the increasing input of chemical fertilizer N. The mean annual emission in 1990s was estimated to be 204 Gg N2O-N, ranging from 159 to 269 Gg N2O-N, and the lowest and the highest emission occurred in 1992 and 1998, respectively.

[Effect of organic material incorporation in rice season on N2O emissions from following winter wheat growing season].

In a field experiment, five fertilizer treatments including chemical fertilizer (CF), rapeseed cake + chemical fertilizer (RC + CF), wheat straw + chemical fertilizer (WS + CF), cow manure + chemical fertilizer (CM + CF), and pig manure + chemical fertilizer (PM + CF), were dedicated to examine the effect of organic materials incorporation in the rice season on N2O emissions from the following winter wheat season and to assess the climatic impacts from CH4 and N2O emissions in a rice-wheat rotation. Organic material was incorporated at the same rate (225 g x m(-2)) for organic treatments at the depth of 10 cm in the soil as the basal fertilizer just before rice transplanting. An identical synthetic nitrogen fertilizer was adopted for all treatments.

[Effects of tillage-cropping systems on methane and nitrous oxide emissions from permanently flooded rice fields in a central Sichuan hilly area of Southwest China].

Using the static opaque chamber method, a field experiment was conducted in situ for two years to study the effects of three cultivation systems on CH4 and N2O emissions from permanently flooded rice fields in a hilly area in Southwest China. The results show that the average CH4 fluxes from a permanently flooded rice field with a single middle rice crop and flooded with no winter crop (PF) were (21.44 +/- 1.

[Angiotensin II up-regulates osteopontin mRNA expression of RAW264.7 macrophages via p38MAPK signaling].

Objective: To investigate the changes of osteopontin (OPN) mRNA expression induced by angiotensin II (AngII) in RAW264.7 macrophages, and to determine the role of p38 mitogen-activated protein kinase (p38MAPK) signaling in up-regulation of OPN mRNA expression.

Methods: RT-PCR was used for examining the OPN mRNA expression, and the phosphorylation of p38MAPK and activating transcription factor2 (ATF2) was detected by Western blot.

[CO2 emission from soil-crop system as influenced by crop growth and tissue N content].

To understand the CO2 emission from soil-crop system as influenced by crop growth and tissue N content, pot and field experiments were carried out during 2001-02 wheat and rice growing seasons. Black chambers were used to take gas samples within a closed soil-crop system. The CO2 emission rate was detected by a gas chromatograph.