Effect Of Gradients Of Precipitation And Temperature And Fertilization On Organic Carbon Of Soils In Northeastern China

Agriculture soil carbon pool can be interrupted strongly by anthropic activity and also can be regulated at a relatively short time scale.The agricultural soil carbon storage plays a vital role on global climate change.The research of immobilizing agricultural soil carbon has become the hotspot of global change.The climate factor affects the soil carbon station strongly and the soil organic carbon pool has been influenced by rainfall and temperature. This thesis is based on the general distributing trend of temperature and rainfall of northeast region to setup the sampling sites,and choose the representative fertilizer treatments at long term fertilization station(summing to twenty-six treatments from four long term fertilization stations),in order to investigate the change of soil organic carbon concentration,storage and labile organic carbon and the effect of long term fertilization treatments on soil organic carbon concentration,storage and labile organic carbon under special hydrothermal conditions.The results indicate that:The distributing characteristics of soil organic carbon and storage within the sampling region is that north is higher than south.The soil organic carbon concentration not only has relationship with average temperature per year,rainfall and effective accumulated temperature,but also with tillage and fertilizer.The correlation between P/t and other two factors is better when characterizing the relationship between soil organic carbon concentration,storage and climate factors.The distributing characteristics of soil labile organic carbon within the sampling region is that north is higher than south.The correlation between labile organic carbon and soil total organic carbon is good and different components have good correlation with each other.The correlation of components of labile organic carbon and climate factors are good.The correlation of the components of liable organic carbon and average temperature per year is larger than that of components of labile organic carbon and precipitation.The correlation of soil microbial quotient and climate factors is higher than that of soil microbial biomass carbon and climate factors.So the indicating effect of soil microbial biomass quotient is more sensitive than soil microbial biomass carbon concentration when characterization and prediction the effect of climate changes on soil organic carbon.Appropriate fertilization protocols can increase the accumulation of soil organic carbon, making the agricultural soil to be sinking not to be source.Under the same hydrothermal conditions adding organic manure and appropriate fertilization can increase soil carbon concentration.The same fertilizer treatments under different hydrothermal conditions differ significantly.Shenyang region:the topsoil organic carbon concentration differs significantly over 18 years of long term fertilization.Compared with unfertilized and pre-experimental soil, applying inorganic-organic fertilizer treatments differ significantly,except M₁N₁ treatment.The content of soil light fraction varies between 4.325 g kg^-1and 6.750 g kg^-1,while that of the N2P2,N4P2,M1N1,M1N1P1 treatments differs insignif(?)cantly and the difference of M2N2P1 and M4N2P1 reach a significant level at 5%comparing with CK.The soil light faction organic carbon concentration varies between 0.875 g kg^-1and 2.075 g kg^-1.The difference of soil light fraction organic carbon between other treatments and CK reach a significant level at 5%.The range of soil microbial biomass carbon is between 195.51 mg kg^-1and 334.02 mg kg^-1.The soil microbial biomass carbon of different fertilizer treatments and CK differs significantly.The soil soluble organic carbon varies between 139.86 mg kg^-1 and 281.10 mg kg^-1.The soil soluble organic carbon of fertilizer treatment and CK differs significantly.The soil particulate organic carbon of different fertilizer treatments varies between 1.918 g kg^-1and 3.100 g kg^-1。The soil particulate organic carbon of applying inorganic-organic fertilizer treatments are all higher than that of applying single inorganic fertilizer and CK.Gongzhuling region:over 25 years of long term fertilization the topsoil organic carbon concentration differs significantly.The soil organic carbon between low level organic manure plot and high level organic manure plot increases by -0.16～0.69 g kg^-1and 11.79～12.74 g kg^-1 respectively,comparing with that of pre-experiment(17.13g kg^-1).The topsoil organic carbon of single inorganic fertilizer treatments declined by 13.49%～16.17%,comparing with that of pre-experiment,which increases by 2.72%～6.01%than CK and differs significantly at 5%. The soil light fraction of different fertilizer treatments differs significantly,varying between 5.325 g kg^-1～17.450 g kg^-1.The proportion of LFOC/TOC varies between 9.0%～18.53%.Soil microbial biomass carbon concentration varies between 296.21mg kg^-1～981.60 mg kg^-1.The soil soluble organic carbon varies between 176.42 mg kg^-1～425.13 mg kg^-1,while the proportion of that to total organic carbon varies between 1.26%～1.78%.The soil particulate organic carbon concentration among treatments varies between 2.763 g kg^-1～10.108 g kg^-1.The difference of soil particulate organic carbon between every treatment and CK reach a significant level expect that of NP.The proportion of particulate organic carbon to total organic carbon differs significantly under different fertilizer applied treatments,varying between 19.76%～33.84%.Haerbin region:over 25 years of fertilization at long term fertilization station,the difference between organic-inorganic fertilizer treatments and CK reach to a significant level at 1%.The content of soil light fraction differs significantly,varying between 4.975 g kg^-1and 13.100 g kg^-1.The soil light fraction organic carbon concentration varies between 1.400 g kg^-1 and 3.792 g kg^-1.The soil microbial biomass carbon concentration varies between 336.14mg kg^-1and 579.53 mg kg^-1.The SMBC concentration among different treatments differs significantly compared with CK.The soil soluble organic carbon concentration varies between 152.22 mg kg^-1and 268.27 mg kg^-1.The range of the ratio of soil soluble organic carbon to soil total organic carbon is 1.13%～1.53%.The concentration of soil particulate organic carbon varies between 2.794 g kg^-1and 5.150 g kg^-1.Compared with CK the soil particulate organic carbon among treatments differs significantly.Hailun region:the soil organic carbon of fertilization and being wasted treatments declined over 20 years compared with pre-experimental soil,especially that of CK.The soil organic carbon of CK treatment declined from 31.32g kg^-1at pre-experiment period to 23.61 g kg^-1at 2005.Compared with that of pre-experiment,the soil organic carbon of NP,NPK and MNPK declined by 20.37%,19.57%and 15.23%respectively.The soil light fraction organic carbon(LFOC)concentration among treatments differs significantly,which varies between 9.800g kg^-1and 18.525g kg^-1.The LFOC of wasteland(natural recovery)treatment is the highest,which is 1.89 times of CK treatment. The ratio of LFOC to TOC varies between 10.32%and 24.73%.The soil microbial biomass carbon concentration varies between 529.62mg kg^-1and 893.20mg kg^-1.The ANOVA results indicate that the soil microbial biomass carbon concentration among treatments differs significantly.The soil soluble organic carbon varies between 328.72mg kg^-1and 469.16mg kg^-1.The soil soluble organic carbon concentration differs significantly except that of NP and NPK treatments.The range of particulate organic carbon(POM-C)concentration of topsoil varies between 4.498g kg^-1and 10.354g kg^-1.The wasteland has the maximum concentration of topsoil POM-C,which is higher than CK by 5.553g kg^-1and increasing rate up to 115.67%. The range of the proportion of POM-C to SOM varies between 19.05%and 35.00%.