CO Unit Of Soil - Field Crop 2 Response Exchange Net Changes In Soil Water Content

A field experiment of winter wheat under different irrigation scheduling was conducted in Beijing's Daxing district China.It adopted gas chromatography technique to observe the fluxes CO2 from winter wheat field,with under a different conditions of irrigation methods,irrigation amounts and lower limit of irrigation.Compared the response relationship between net exchange of CO2 from the winter wheat-soil unit and soil moisture content transformation.First,the study was analyzed correlativity between the unit of soil CO2 flux and the correlation and the net CO2 exchange in the whole day based on three typical operation modes among 09:00?11:00,13:00?15:00,17:00?19:00.Then identify principles of soil water content and soil CO2 exchange net in crop-soil unit.And through the way of flood irrigation,sprinkler irrigation and drip irrigation combined with different irrigation amounts and lower limit of irrigation to study the CO2 net exchange and the soil water content.Figure out the suitable ranges of soil water content for winter wheat in this region,and analysis the different irrigation systems for crop-soil unit the impact of water saving,emission reduction,and so on,in order to put forward the feasible measures of farmland management.The experimental results showed that:(1)A linear positive correlation in soil carbon emissions between three typical operation modes,the representative of CO2 net exchange in 09:00?11:00 is higher.(2)By the soil water processing plant-the unit net exchange in crop root period to maturity of the CO2 rising after falling first approximation the tendency of the "U"type.(3)Crops-soil unit in the whole growth period on soil carbon sequestration function,CO2 exchange cumulative net amount is not has been increased with the increase of the irrigation water.(4)By several times,appropriate control irrigation than conventional irrigation in heading and maturity of one-time traditional net CO2 exchange can play a regulatory role,to a certain extent,have the effect of water saving and emissions reduction.(5)Scope of "water saving emission reduction" system of irrigation water:no difference based on irrigation,irrigation water in between 0.24?0.32m3 is the most suitable for the study area of winter wheat in the whole range of irrigation water during birth.(6)With the same cut-off irrigation and irrigation water,irrigation and drip irrigation are to absorb more CO2 than flooding method at the same time have a higher correlation between the response relation.With the same number of irrigation water andirrigation plots,with relatively high irrigation water floor can absorb more carbon dioxide.(7)Different irrigation system for the growth of winter wheat in the impact of difference;Winter wheat plant height and leaf area index have similar trends.(8)The region of winter wheat sowing date can be appropriately delay,on the basis of save winter irrigation water,according to set the lower limit of soil water content,time,amount of controlled irrigation,key growth period under the regulation of water uptake of carbon dioxide.