长期施肥对栗褐土有机碳矿化的影响  

Effect of long-term fertilization on organic carbon mineralization of cinnamon soil

作　　者：王朔林 杨艳菊[2] 王改兰[1] 赵旭[1] 陈春玉[1] 黄学芳 

机构地区：[1]湖南农业大学资源环境学院,湖南长沙410128 [2]南京师范大学地理科学学院,南京210046 [3]山西农业科学院旱地农业研究中心,山西太原030031

出　　处：《植物营养与肥料学报》2016年第5期1278-1285,共8页Journal of Plant Nutrition and Fertilizers

基　　金：国家国际科技合作专项(2011DFR31230)资助

摘　　要：【目的】土壤有机碳矿化是土壤中重要的生物化学过程,与土壤养分的释放、土壤质量的保持以及温室气体的形成密切相关。本文以25年长期定位施肥试验为依托,对栗褐土土壤有机碳矿化速率、有机碳累积矿化量的动态变化进行研究,为科学管理土壤肥力、增加栗褐土碳汇、减少温室气体排放提供依据。【方法】田间试验开始于1988,共设置8个施肥处理:不施肥(CK);单施氮肥(N);氮磷肥合施(NP);单施低量有机肥(M_1);低量有机肥与氮肥合施(M_1N);低量有机肥与氮磷肥合施(M_1NP);高量有机肥与氮肥合施(M_2N);高量有机肥与氮磷肥合施(M_2NP)。于2013年玉米播种前,采集耕层(0—20 cm)土壤样品,采用室内培养方法,对土壤碳矿化释放CO_2的数量和速率进行测定,并利用一级动力学方程计算出土壤有机碳库潜在矿化势和周转速率。【结果】各肥料处理不同程度地提高了栗褐土总有机碳含量,以高量有机肥与化肥配施作用最为显著。与CK相比,M_2N、M_2NP处理土壤总有机碳含量增加了121.1%、166.8%。不同处理土壤样品培养有机碳矿化速率均在第一天达到峰值,随后急剧下降。5 d后,下降趋缓,不同处理CO_2产生速率趋于一致。培养期间,各处理矿化速率变化符合对数函数关系。长期施用不同肥料均可以提高栗褐土有机碳的矿化速率,其大小顺序为:有机肥与化肥配施>单施有机肥>单施化肥>对照。培养57 d后,各处理土壤有机碳累积矿化量为555.0~980.3mg/kg,以M_2NP、M_1N的累积量较高,为对照的1.77倍、1.73倍。长期施肥栗褐土有机碳矿化率呈下降趋势,以处理M_2NP下降最明显,与对照相比,降低了6.3个百分点。施肥处理土壤的潜在矿化势均高于对照,M_1N、M_2NP最高,为923.7 mg/kg和926.4 mg/kg,较对照增加了74.0%和74.5%。不同施肥处理均可明显提升土壤有机碳的周转速率,减少周转时间,其中处理M_1NP、M_2NP效�【Objectives】Mineralization of soil organic carbon is an essential process of biochemistry in soils,which is closely related to release of soil nutrients, maintenance of soil quality, and formation of greenhouse gases. This paper is to study the effects of different fertilizing treatments on dynamic changes of soil organic carbon mineralization rate and cumulative decomposition in Cinnamon soils for better managements of soil fertility, increasing carbon sinks and decreasing greenhouse gas emissions. 【Methods】Since 1988, a fieldexperiment was conducted in 8 different fertilization treatments： no fertilizer（CK）, inorganic N（N, 120 kg/hm^2）inorganic N and P（NP, P_2O_5 75 kg/hm^2）, low amount of organic manure（M_1, 22500 kg/hm^2）, low amount of organic manure plus inorganic N（M_1N）, low amount organic manure plus inorganic N and P（M_1NP）, high amoun organic manure plus inorganic N（M_2N） and high amount organic manure plus inorganic N and P（M_2NP）. Soil samples were collected at 0–20 cm depth before sowing in 2013. Carbon dioxide cumulative emission and mineralization rate were determined by incubation method. First-order kinetic model was used to calculate potential mineralization and turnover rates. 【Results】 All the long-term fertilization treatments increased total organic carbon in the 0–20 cm depth of soil. The effects of manure combined with chemical fertilizer application, especially M_2 N and M_2 NP were more obvious than those in CK total organic C in M_2 N and M_2 NP was increased by 121.1% and 166.8%, respectively. The incubation results show that mineralization rates of soi organic carbon in all the treatments are the highest in the first day and then decreased rapidly. After 5 days incubation, the mineralization rate decrease slowdown. The changes of mineralization rates of soil organic carbon of all the treatment were in agreement with the logarithmic function relationship. Long-time fertilization enhanced the mineralization rates of soil organic carbon

关 键 词：长期施肥 栗褐土 有机碳矿化 

分 类 号：S153.6[农业科学—土壤学]