Citrus Orchard Soil Active Organic Carbon Pool And Carbon Release Patterns Under Different Management Measures

Jiangxi province, located in mid-subtropical monsoon climate zone, is a typical redsoil erosion area in southern China. This study was conducted in De’an ecologicalexperimental citrus orchard park of Jiangxi province soil and water conservationresearch institute to investigate the soil total carbon, microbial biomass carbon,particulate organic carbon and soil respiration in this citrus orchard park where wereplanted different vegetation types (pasture,crop rotation crops, terraces)with differentsoil management measures. The results of this study were as follows:(1) The order of total organic carbon content in pasture, crop rotation, terracing andThe control plot was7.99±0.73、6.36±0.59、5.50±0.43and4.83±0.32g kg-1,respectively. The total soil organic carbon content were significant different amonggrass, rotation crop, terraces measures and control plot. The spatial distribution of thetotal soil organic carbon content among different vegetation types were significantdifferent. The order of its spatial distribution were0-10>10-20>20-40>40-70>70-100cm.(2)The soil microbial biomass carbon content under rotation crops was the highest(264.41±24.83mg kg-1) while the lowest content (176.86±11.44mg kg-1) in grasscompared to that in other vegetation types. From the time change on soil microbialbiomass carbon content were compared, grass, crops in time of two measures showsignificant differences, terraced measures and the control group had no significantdifference. The soil microbial biomass carbon content of three kinds of measures hasthe highest value in different month. From the vertical distribution of soil microbialbiomass carbon to compare the results of soil microbial biomass carbon contentdecreased with the increase of soil depth.(3) Compare soil particulate organic carbon under differences management measures,crop group has highest soil particulate organic carbon than the other measures,itscontent is4.02±0.30g kg-1. From the time change to compare soil particulate organiccarbon4,6,9month of soil particulate organic carbon content had no significantdifference. From the comparison results of vertical distribution of the particles oforganic carbon of soil particles generally is inversely proportional to the depth of soilorganic carbon content, the deeper the soil depth, the less content.(4) Eight experimental plots temperature, surface temperature, soil temperature andvegetation canopy are basically the same, but the big difference vegetation.Experimental samples under different management measures of soil respiration ratefluctuations are not same,grass, crop rotation and terraced soil respiration rate fluctuations more obvious, rising also declined; the control respiratory rate isrelatively stable, continues to decline.