不同施肥处理红壤性水稻土团聚体有机碳矿化特征  

Organic Carbon Mineralization in Aggregate Fractions of Red Paddy Soil Under Different Fertilization Treatments

作　　者：陈晓芬[1] 刘明[1,2] 江春玉 吴萌[1] 李忠佩[1,2] CHEN XiaoFen1, LIU Ming1,2, JIANG ChunYu1, WU Meng1, LI ZhongPei1,2(1.Institute of Soil Science, Chinese Academy of Sciences/State Key Laboratory of Soil and Sustainable Agriculture, Nanjing 210008; 2.University of Chinese Academy of Sciences, Beijing 10004)

机构地区：[1]中国科学院南京土壤研究所/土壤与农业可持续发展国家重点实验室,南京210008 [2]中国科学院大学,北京100049

出　　处：《中国农业科学》2018年第17期3325-3334,共10页Scientia Agricultura Sinica

基　　金：国家自然科学基金(41601270;41430859);中国博士后基金(2016M601904)

摘　　要：【目的】在已有团聚体碳氮分布研究的基础上,进一步研究不同施肥处理红壤性水稻土团聚体有机碳矿化特征,并分析有机碳矿化的影响因素,为揭示施肥对土壤肥力的影响及土壤有机碳矿化作用机制提供理论依据。【方法】以长期定位施肥红壤性水稻土为研究对象,包括9个处理:不施肥(CK)、有机质循环(C)、氮肥(N)、氮肥+有机质循环(NC)、氮磷肥(NP)、氮磷钾肥(NPK)、氮磷钾肥+有机质循环(NPKC)、氮钾肥(NK)和氮磷钾肥+1/2秸秆回田(NPKS)。运用湿筛法得到>2 mm、1—2 mm、0.25—1 mm、0.053—0.25 mm和<0.053 mm 5个粒级团聚体,观测团聚体和全土有机碳矿化动态变化,测定团聚体中微生物生物量碳含量和转化酶活性。【结果】全土和>1 mm团聚体有机碳矿化速率在培养前期快速下降,之后逐渐降低至稳定状态,而<1 mm粒级尤其是0.053—0.25 mm团聚体,有机碳矿化速率在培养前期降低幅度减小并更早达到稳定状态。有机碳累积矿化量在>2 mm和1—2 mm团聚体中最高,在0.053—0.25 mm团聚体中最低。与对照相比,施磷肥处理(NP和NPK)各粒级团聚体有机碳累积矿化量平均提高17.0%—62.1%,施有机肥处理(C、NC和NPKC)则平均提高25.0%—80.5%。>2 mm和0.25—1 mm团聚体对全土有机碳矿化的贡献最大,分别为21.0%—42.5%和20.6%—32.7%。>0.25 mm大团聚体微生物生物量碳含量和转化酶活性均高于<0.25 mm微团聚体。施磷肥处理各粒级团聚体微生物生物量碳含量较对照平均高73.4%—92.0%,施有机肥处理平均高60.8%—99.6%。磷肥和有机肥的施用显著提高>0.25 mm大团聚体转化酶活性,其中NC处理大团聚体转化酶活性最高,较对照提高46.0%—135.0%。团聚体有机碳累积矿化量与有机碳、全氮、微生物生物量碳含量及转化酶活性均呈极显著正相关,但与有机碳的相关性最大。【结论】大团聚体在土壤有机碳矿化中发挥主导作用;有机�【Objective】 Based on investigation of organic carbon and total nitrogen distribution in aggregates of red paddy soil under different fertilization treatments, in this study, soil organic carbon mineralization in aggregate fractions was further investigated, and the influence factors of organic carbon mineralization were also analyzed. The research results could help to better understand the mechanisms of influence of fertilization on soil fertility and organic carbon mineralization.【Method】Soil samples were collected from a long-term field experiment conducted in red paddy soil, which included nine fertilization treatments, namely no fertilizer（CK）, organic cycling（C）, N fertilizer（N）, N fertilizer plus organic cycling（NC）, N and P fertilizer（NP）, N, P and K fertilizer（NPK）, N, P and K fertilizer plus organic cycling（NPKC）, N and K fertilizer（NK）, N, P and K fertilizer plus 1/2 rice straw incorporation（NPKS）. Those Soil samples were separated into five aggregate-size classes by wet sieving, as〉2 mm, 1-2 mm, 0.25-1 mm, 0.053-0.25 mm and 〈0.053 mm. The dynamics of organic carbon mineralization in aggregates and bulk soils were detected, and microbial biomass carbon contents and invertase activity in aggregate fractions were mearsured.【Result】The mineralization rate of organic carbon in bulk soils and 〉1 mm aggregates decreased rapidly during the early stage of incubation, then decreased gradually and reached a stable state. However, the mineralization rate of organic carbon in 〈1 mm size classes, especially in 0.053-0.25 mm, showed a lesser decrease during the early stage of incubation and reached stability faster. The cumulative amounts of organic carbon mineralization were highest in 〉2 mm and 1-2 mm aggregates while those were lowest in 0.053-0.25 mm ones. Compared with CK, P fertilizer application（NP and NPK） and organic manure application（C, NC and NPKC） increased the cumulative amounts of organic carbon mineralization in aggregates by average 1

关 键 词：土壤团聚体 有机碳矿化 微生物生物量碳 转化酶 红壤性水稻土 长期施肥 

分 类 号：S153[农业科学—土壤学]