Location
The Changsha subtropical paddy field and tea field fluxes measuring site is located in the Northeast of Changsha city (28°35′N，113°20′E, 80 m a.s.l.), and affiliated to Changsha Research Station for Agricultural & Environment Observation, Institute of Subtropical Agriculture, Chinese Academy of Sciences (Changsha Station). This site has the typical agroecosystems in the mid-subtropical hilly region of China.
Climatic
The site is characterized by a subtropical humid monsoon climate with the following annual means: air temperature,17.5℃; precipitation, 1330 mm; sunshine, 1651 h; accumulated temperature >0 ℃, 6335 ℃; and frost-free period, 280 days.
Vegetation and soil
The Changsha station is an agricultural research station with double cropping rice and tea as the primary crops. The soil types at the site mainly include granite red soil and paddy soil. Soil texture is loam in the tillage layers for both red soil and paddy soil, and changes to loam, sandy loam, sand for red soil and to clay loam, loam and sandy loam for paddy soil with the increase of soil depths
Observation system
The Changsha subtropical paddy field and tea field fluxes measuring site have set up a weather station, close-path eddy-covariance flux measurement systems for CO2/CH4/H2O and N2O/CO, a gradient flux measurement system for NH3, atmospheric dry and wet deposition measurement systems and CO2, CH4, N2O and NOx flux measurement systems based on chamber method in both a typical paddy field and a typical tea field.
Principal Investigator
Yong Li
E-mail: yli@isa.ac.cn
Station director
Yong Li Professor
Assistant station director
.Runlin Xiao Professor
Members
.Jinshui Wu (nstitute Director) Professor
Daoyou Huang Professor
Jianlin Shen Assoc.Professor
Ying Wang Assit. Professor
Yuyuan Li Assoc.Professor
CAS
Study and demonstration of the system for preventing and controlling agricultural nitrogen and phosphorus pollution from sources in the subtropical hilly region (Jinshui Wu 2013-2015）
MOST
Studies on mechanisms and key technologies for greenhouse gas emissions reduction from agricultural systems in the subtropical China （Jinshui Wu 2011-2014）
Catchment-scale carbon and nitrogen cycling model development and verification. （Yong Li 2012-2016）
NNSFC
Studies on spatial-temporal characteristics of soil N2O emissions in a typical subtropical hilly tea field （Yong Li 2012-2015）
Characteristics, influencing factors and parameterization of ammonia exchange flux between paddy field and atmosphere. （Jianlin Shen 2014-2017）
1
We quantified the annual N2O emission fluxes in typical tea fields in subtropical region, obtained representative N2O emission factors in subtropical tea fields. By large-sample sampling, we quantified the spatial-temporal variances of N2O emissions in a tea field with different elevation, found out the primary environmental factors that influenced the variances and developed the model for modeling N2O emissions from hilly tea fields..
2
We quantified the net greenhouse gas emissions from double rice cropping systems under various water, carbon and nitrogen management measures, found out the primary environmental factors that affected greenhouse gas emissions, and firstly discovered that application of straw-derived biochar reduced CH4 emissions by 40% in double rice cropping systems.
3
We established four atmospheric nitrogen deposition measurement systems in Jinjing river catchment, quantified nitrogen deposition in the main land use types in the catchment, found out the sources of nitrogen deposition and estimated the contribution of nitrogen deposition to diffuse nitrogen pollution in the catchment.
4
We published more than 10 peer-reviewed SCI journal papers about measurement and modeling of carbon and nitrogen fluxes in subtropical tea fields and paddy fields in Global biogeochemical Cycles, Biogeosciences, Agriculture, Ecosystems & Environment、Atmospheric Environment, Geoderma, European Journal of Soil Biology, etc...