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土壤管理方式影响土壤碳库储量,进而影响土壤的源汇功能。该研究通过测定草地(GL)、裸地(BL)、农田无肥(NF)、化肥(NP)和化肥配施有机肥(NPM)处理的有机碳含量和土壤容重,估算了不同土地利用和施肥管理方式下的土壤有机碳密度的变化及农田的固碳潜力。结果表明,土壤有机碳含量表层最高而且变化较大,向下逐渐降低且变化较小。对于不同植被覆盖的3个处理,草地0-20cm土层土壤有机碳含量比裸地和无肥分别高出20.6%和16.4%。对于不同施肥管理方式,化肥有机肥配施土壤有机碳含量比无肥和化肥分别高出25.4%和15.5%,所有处理有机碳含量在160-200cm土层没有显著差异。0-40cm土层及0-100cm土体有机碳密度的变化趋势是NPM>GL>NP>NF>BL;40cm以下有机碳储量无规律性变化,表现出较大的变异性,这可能与土壤本身的空间异质性有关。草地100cm土体有机碳储量比裸地和无肥分别增加6.8%和5.7%,裸地和无肥无显著差异;化肥加有机肥100cm土体有机碳储量比化肥和无肥分别增加10.4%和5.9%。经估算,松嫩平原黑土区0-100cm土体有机碳库储量约为1.35Pg,农田有机培肥后碳库储量可达到0.96Pg,其固碳潜力约为0.05Pg。0-100cm土体有机碳密度与0-20cm土层有机碳含量及有机碳密度呈极显著正相关(r=0.99;r=0.97,P<0.01),表明土壤表层有机碳含量及密度对0-100cm土壤有机碳库具有决定作用。
Soil management affects the soil carbon storage and thus affects the source and sink function of soil. In this study, the organic carbon content and bulk density of soils treated with GL, bare land, NF, NP and NPM were estimated to evaluate the effects of different land use and Variation of Soil Organic Carbon Density under Fertilization Management and Potential of Carbon Sequestration in Farmland. The results showed that the content of soil organic carbon was the highest and varied greatly, and then decreased gradually and changed little. For the three treatments with different vegetation cover, the content of soil organic carbon in 0-20cm soil layer was 20.6% and 16.4% higher than bare soil and no fertilizer, respectively. For different fertilization management modes, the organic carbon content of manure and organic manure application were 25.4% and 15.5% higher than those of non-manure and fertilizer respectively. There was no significant difference in the contents of all organic carbon in 160-200 cm soil layer. The trend of organic carbon density in 0-40cm soil layer and 0-100cm soil is NPM> GL> NP> NF> BL. There is no regular change in organic carbon storage below 40cm, showing great variability, which may be related to soil Their own spatial heterogeneity. Compared with bare land and no land, grassland organic carbon storage increased by 6.8% and 5.7% respectively compared with bare land and no fertilizer, bare land and no fertilizer had no significant difference; 5.9%. It is estimated that the soil organic carbon pool of 0-100cm in the black soil area of Songnen Plain is about 1.35Pg, and the carbon stock of organic fertilizers in farmland can reach 0.96Pg. The carbon sequestration potential is about 0.05Pg. There was a significant positive correlation (r = 0.99; r = 0.97, P <0.01) between 0-100cm soil organic carbon and organic carbon and soil organic carbon in 0-20cm soil layer, indicating that the organic carbon content and density of soil surface were 0 -100cm soil organic carbon pool has a decisive role.