摘要
为研究土壤团聚体有机碳分布对CO_(2)浓度增加和秸秆还田的响应,本研究以东北黑土区长期CO_(2)增加定位试验平台为依托,设置4个处理,分别为对照(CK)、增加CO_(2)浓度达1259.72 mg·m^(-3)(EC)、秸秆还田(ST)和增加CO_(2)浓度结合秸秆还田(EC+ST)。结果表明:EC与ST处理对土壤总有机碳含量无显著影响,但EC+ST处理使土壤总有机碳含量提升3.09 g∙kg^(-1)(P<0.05)。EC处理下土壤团聚体占比变化无显著影响,但分形维数(D)增加0.06,土壤团聚体稳定性降低。ST与EC+ST处理使>0.5~1 mm大团聚体占比分别提高14.98个百分点与8.20个百分点,此外,ST处理使≤0.053 mm微团聚体占比减少12.88个百分点,水稳性团聚体数量(R0.25)增加0.14,平均质量直径(dMW)增加0.08 mm,D减少0.11(P<0.05),土壤团聚体稳定性增强;EC+ST处理使>1 mm大团聚体占比增加4.07个百分点,dMW增加0.11 mm,土壤团聚体稳定性增加。EC与EC+ST处理较CK处理相比,分别使≤0.053 mm微团聚体土壤有机碳含量提升了0.66 g∙kg^(-1)和1.98 g∙kg^(-1);ST处理使>1 mm大团聚体土壤有机碳含量提高0.55 g∙kg^(-1),>0.25~0.5 mm大团聚体有机碳含量降低1.13 g∙kg^(-1);EC+ST处理使>1 mm大团聚体土壤有机碳含量减少3.05 g∙kg^(-1)(P<0.05)。EC处理使≤0.053 mm微团聚体有机碳贡献率增加9.14个百分点,而ST处理则使该部分减少10.54个百分点,同时>0.5~1 mm大团聚体有机碳贡献率增加14.35个百分点,EC+ST处理使>1 mm大团聚体和>0.5~1 mm大团聚体有机碳贡献率分别增加3.25个和6.74个百分点,>0.053~0.25 mm微团聚体有机碳贡献率降低5.82个百分点。研究表明,秸秆还田可以弥补CO_(2)浓度增加导致的土壤总有机碳含量下降与团聚体结构变差的不利结果。虽然秸秆还田时其本身矿化会向大气中释放CO_(2),但是在未来大气CO_(2)浓度增加的背景下,秸秆还田是提高黑土有机碳含量的潜在有效措施,值得在东北黑土区推广,�
The responses of organic carbon distribution in soil aggregates to CO_(2) enrichment and straw return were studied to provide theoretical evidence for the carbon sequestration and mitigation of black soil.Based on the long-term CO_(2) enrichment experimental platform located in the black soil region of northeast China,four treatments were set.The treatments were the control(CK),increasing CO_(2) concentration to 1259.72 mg·m^(-3)(EC),straw returning(ST),and increasing CO_(2) concentration combined with straw returning(EC+ST).The results showed that the EC and ST treatments had no significant effect on the total soil organic carbon,whereas the EC+ST treatment increased total soil organic carbon by 3.09 g∙kg^(-1)(P<0.05).The EC treatment had no significant effect on the proportion of soil aggregates,although the fractal dimension(D)increased by 0.06 and the stability of the soil aggregates decreased.Both the ST and EC+ST treatments increased the proportion of>0.5–1 mm macro-aggregates by 14.98 percentage points and 8.20 percentage points,respectively.In addition,the ST treatment reduced the proportion of≤0.053 mm micro-aggregates by 12.88 percentage points,increased the number of waterstable aggregates(R0.25)by 0.14,and the average weight diameter(dMW)was increased by 0.08 mm,furthermore,D decreased by 0.11(P<0.05),and the stability of soil aggregates was enhanced,whilst the EC+ST treatment increased the proportion of>1 mm macro-aggregates by 4.07 percentage points,and also increased the dMW by 0.11 mm and increased the stability of soil aggregates.Compared with CK,the EC and EC+ST treatments increased the soil organic carbon content of≤0.053 mm micro-aggregates by 0.66 g∙kg^(-1)and 1.98 g∙kg^(-1),respectively.In addition,the ST treatment increased the>1 mm macro-aggregate content of soil organic carbon by 0.55 g∙kg^(-1),whilst>0.25–0.5 mm macro-aggregates decreased by 1.13 g∙kg^(-1).In addition,the EC+ST treatment reduced>1 mm macro-aggregates by 3.05 g∙kg^(-1)(P<0.05).EC treatment also increa
作者
岳娅
薛海清
冯茜
苗欢
苗淑杰
乔云发
YUE Ya;XUE Haiqing;FENG Qian;MIAO Huan;MIAO Shujie;QIAO Yunfa(School of Applied Meteorology,Nanjing University of Information Science&Technology,Nanjing 210044,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2023年第4期943-950,共8页
Journal of Agro-Environment Science
基金
国家自然科学基金项目(42177279)
江苏省农业自主创新项目[CX(21)3170]。
