共查询到19条相似文献,搜索用时 265 毫秒
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利用室内培养实验,分析燥红壤和砖红壤中分别施加N0(不添加氮素)、N1(氮添加量为100mg·kg−1)、N2(氮添加量为200mg·kg−1)和N3(氮添加量为300mg.kg−1)4个水平氮后对土壤性质及N2O、CO2排放的影响。结果表明:氮肥添加显著降低了土壤pH和有机碳含量。相较于N0,燥红壤N1、N2和N3处理pH和有机碳降幅分别为8%~18%和4%~12%,砖红壤降幅分别为5%~23%和3%~15%;添加氮肥后各处理土壤全氮含量显著增加,燥红壤和砖红壤分别增加15%~54%和13%~52%。氮施入增加了土壤NH4+−N和NO3−−N含量,各处理土壤铵态氮和硝态氮含量均表现为N3>N2>N1>N0。氮添加促进土壤N2O和CO2排放,相较于N0,燥红壤N2O和CO2累积排放量分别增加1176%~2425%和124%~281%,砖红壤分别增加1054%~1887%和138%~256%。施氮量和土壤类型是影响农田土壤N2O和CO2排放的重要因素。土壤N2O和CO2排放与施氮量呈线性显著相关,减少施肥是降低土壤N2O排放最直接和最有效的措施。与砖红壤相比,燥红壤N2O和CO2排放对氮素添加的响应更敏感。 相似文献
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为分析不同林龄亚热带常绿阔叶次生林和杉木(Cunninghamia lanceolata)种植对土壤氮淋溶的影响,采用土柱微宇宙原位培养,分别比较9年生和45年生次生林(以米槠Castanopsis carlesii为建群种)之间、米槠和杉木人工林(均为9年生)之间的土壤总氮、硝态氮和铵态氮浓度及通量。结果表明:(1)4种类型森林土壤总氮和硝态氮浓度均表现为45年生次生林>9年生次生林>杉木人工林>米槠人工林;铵态氮浓度则为45年生次生林>杉木人工林>9年生次生林>米槠人工林。(2)4种类型森林土壤总氮和硝态氮的淋溶通量在整个试验期表现为9年生次生林>45年生次生林>杉木人工林>米槠人工林;5—8月4种类型森林土壤氨态氮淋溶通量差异较大,但大体上表现为杉木人工林>45年生次生林>9年生次生林>米槠人工林。(3)9年生和45年生次生林、米槠人工林、杉木人工林土壤总氮年淋溶量分别为14.24,13.27,7.26,10.97 [g/(m2·a)],硝态氮年淋溶量分别为10.88,9.97,5.35... 相似文献
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为探究外源碳氮添加对农田土壤温室气体排放的影响,以农田黑土为对象,在25℃和淹水条件下开展室内培养试验,研究外源碳(葡萄糖和乙酸)和氮(硫酸铵)添加对温室气体排放的影响。结果表明,淹水条件碳氮配施显著降低了土壤硝态氮含量,以氮肥配施葡萄糖处理效果更明显。与不施肥的对照处理相比,单施氮肥处理对CO2排放速率无显著影响;与单施氮肥处理相比,碳氮配施显著提高了CO2的排放速率,氮肥配施葡萄糖处理和氮肥配施乙酸处理的CO2累积排放量分别为单施氮肥处理的3.93和2.44倍。与不施肥的对照处理相比,单施氮肥显著增加了N2O排放速率,其累积排放量是对照处理的3.60倍;与单施氮肥处理相比,氮肥配施葡萄糖处理仅在第1天对N2O排放速率有显著促进效果,培养期间N2O累积排放量与单施氮肥处理无显著差异;氮肥配施乙酸处理对N2O排放速率的促进效果持续了5 d,其N2O累积排放量是单施氮肥处理的3.58倍。与不施肥的对照处理相比,单施... 相似文献
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【目的】探究红壤区玉米关键生育期氧化亚氮(N2O)的排放量及影响因素,为红壤区玉米季温室气体减排提供理论支撑。【方法】典型红壤长期施肥定位试验始于1990年,选取不施肥(CK)、氮钾化肥配施(NK)、氮磷钾化肥配施(NPK) 3个处理,监测玉米苗期、喇叭口期、灌浆期和成熟期N2O排放、温度和降雨量,测定了表层土壤理化性状和硝酸还原相关酶的活性。【结果】与CK相比,NK和NPK处理均显著提高了N2O累积排放量,NPK处理显著增加苗期N2O累积排放量,而NK处理显著提高了喇叭口期和灌浆期N2O累积排放量,但两个处理的玉米生育期N2O累积排放总量没有显著差异。从玉米苗期到成熟期,NK处理土壤pH整体呈下降趋势,降低了17.8%,而CK和NPK处理无显著变化;CK、NK和NPK处理土壤有机碳(SOC)整体呈上升趋势,分别较灌浆期升高了15.2%、16.4%和16.2%,NH4+-N含量呈逐渐降低趋势,而NO3<... 相似文献
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【目的】施用硝化抑制剂是削减农田N2O排放的有效措施,本文研究不同种类硝化抑制剂对土壤N2O排放的影响,为选择高效硝化抑制剂以实现黑土N2O减排提供科学依据。【方法】在黑龙江省东部典型旱作黑土区进行田间试验。设置6个处理:不施氮肥(N0),常规施氮(N200),减氮20%(N160),减氮20%分别配施硝化抑制剂双氰胺(N160+DCD)、3,4-二甲基吡唑磷酸盐(N160+DMPP)和2-氯-6 (三氯甲基)-吡啶(N160+CP)。测定全年土壤N2O排放通量,同步测定土壤温度和含水量以及玉米生长季土壤铵态氮(NH4+-N)、硝态氮(NO3--N)和可溶性有机碳(DOC)含量。【结果】施氮显著提高了土壤NH4+-N含量,且各施氮处理间差异不显著。施用硝化抑制剂处理降低了土壤NO3--N含量,DCD和DMPP处理的NO3--N... 相似文献
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不同配比有机无机肥料对菜地N2O排放的影响 总被引:3,自引:1,他引:2
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中亚热带杉木人工林和米槠次生林树干茎流和穿透雨磷的动态特征 总被引:1,自引:1,他引:0
磷(P)伴随树干茎流和穿透雨输入到森林,成为补充亚热带森林生态系统P流失的一个重要途径,但其在不同类型生态系统中的动态特征缺乏必要的关注。以中亚热带杉木人工林和米槠次生林为研究对象,通过测定2015年6月至2018年8月间树干茎流和穿透雨中P浓度,探讨了2个林分树干茎流和穿透雨P浓度的差异、季节变化特征及影响因素。结果表明,杉木人工林树干茎流和穿透雨P浓度变化范围分别为0.002~0.026,0.003~0.024 mg/L,米槠次生林树干茎流和穿透雨P浓度变化范围分别为0.003~0.024,0.003~0.031 mg/L,2个林分树干茎流和穿透雨P浓度均在夏季表现出显著差异。2个林分的树干茎流P浓度均为夏季高于冬季,杉木人工林穿透雨P浓度在季节上无显著差异,而米槠次生林夏秋季较高,冬春季偏低,树干茎流P浓度略微高于穿透雨。2个林分的树干茎流量在4个季节均具有显著差异,米槠次生林均高于杉木人工林,而穿透雨量在季节上无差异。杉木人工林P浓度与树干茎流量和穿透雨量均呈负相关关系,而米槠次生林P浓度与树干茎流量和穿透雨量均呈正相关关系。表明不同林分林冠结构和形态学特征的差异能显著影响亚热带森林生态系统降水中P的再分配。研究结果为深入认识森林生态系统P随水文过程的动态特征提供基础数据。 相似文献
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生物质炭对集约化菜地N2O排放和蔬菜产量的影响 总被引:1,自引:0,他引:1
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The amounts of N2O released in periods of alternate freezing and thawing depend on site and freezing conditions, and contribute considerably to the annual N2O emissions. However, quantitative information on the N2O emission level of forest soils in freeze‐thaw cycles is scarce, especially with regard to the direct and indirect effect of tree species and the duration of freezing. Our objectives were (i) to quantify the CO2 and N2O emissions of three soils under beech which differed in their texture, C and N contents, and humus types in freeze‐thaw cycles, and (ii) to study the effects of the tree species (beech (Fagus sylvatica L.) and spruce (Picea abies (L.) Karst.)) for silty soils from two adjacent sites and the duration of freezing (three and eleven days) on the emissions. Soils were adjusted to a matric potential of –0.5 kPa, and emissions were measured in 3‐hr intervals for 33 days. CO2 emissions of all soils were similar in the two freeze‐thaw cycles, and followed the temperature course. In contrast, the N2O emissions during thawing differed considerably. Large N2O emissions were found on the loamy soil under beech (Loam‐beech) with a maximum N2O emission of 1200 μg N m–2 h–1 and a cumulative emission of 0.15 g N m–2 in the two thawing periods. However, the sandy soil under beech (Sand‐beech) emitted only 1 mg N2O‐N m–2 in the two thawing periods probably because of a low water‐filled pore space of 44 %. The N2O emissions of the silty soil under beech (Silt‐beech) were small (9 mg N m–2 in the two thawing periods) with a maximum emission of 150 μg N m–2 h–1 while insignificant N2O emissions were found on the silty soil under spruce (0.2 mg N m–2 in the two thawing periods). The cumulative N2O emissions of the short freeze‐thaw cycles were 17 % (Sand‐beech) or 22 % (Loam‐beech, Silt‐beech) less than those of the long freeze‐thaw cycles, but the differences between the emissions of the two periods were not significant (P ≤ 0.05). The results of the study show that the amounts of N2O emitted in freeze‐thaw cycles vary markedly among different forest soils and that the tree species influence the N2O thawing emissions in forests considerably due to direct and indirect impacts on soil physical and chemical properties, soil structure, and properties of the humus layer. 相似文献
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AbstractBoth nitrogen (N) deposition and biochar can affect the emissions of nitrous oxide (N2O), carbon dioxide (CO2) and ammonia (NH3) from different soils. Here, we have established a simulated wet N deposition experiment to investigate the effects of N deposition and biochar addition on N2O and CO2 emissions and NH3 volatilization from agricultural and forest soils. Repacked soil columns were subjected to six N deposition events over a 1-year period. N was applied at rates of 0 (N0), 60 (N60), and 120 (N120) kg Nh a?1 yr?1 without or with biochar (0 and 30 t ha?1 yr?1). For agricultural soil, adding N increased cumulative N2O emissions by 29.8% and 99.1% (p < 0.05) from the N60 and N120 treatments, respectively as compared to without N treatments, and N120 emitted 53.4% more (p < 0.05) N2O than the N60 treatment; NH3 volatilization increased by 33.6% and 91.9% (p < 0.05) from the N60 and N120 treatments, respectively, as compared to without N treatments, and N120 emitted 43.6% more (p < 0.05) NH3 than N60; cumulative CO2 emissions were not influenced by N addition. For forest soil, adding N significantly increased cumulative N2O emissions by 141.2% (p < 0.05) and 323.0% (p < 0.05) from N60 and N120 treatments, respectively, as compared to without N treatments, and N120 emitted 75.4% more (p < 0.05) N2O than N60; NH3 volatilization increased by 39.0% (p < 0.05) and 56.1% (p < 0.05) from the N60 and N120 treatments, respectively, as compared to without N treatments, and there was no obvious difference between N120 and N60 treatments; cumulative CO2 emissions were not influenced by N addition. Biochar amendment significantly (p < 0.05) decreased cumulative N2O emissions by 20.2% and 25.5% from agricultural and forest soils, respectively, and increased CO2 emissions slightly by 7.2% and NH3 volatilization obviously by 21.0% in the agricultural soil, while significantly decreasing CO2 emissions by 31.5% and NH3 volatilization by 22.5% in the forest soil. These results suggest that N deposition would strengthen N2O and NH3 emissions and have no effect on CO2 emissions in both soils, and treatments receiving the higher N rate at N120 emitted obviously more N2O and NH3 than the lower rate at N60. Under the simulated N deposition circumstances, biochar incorporation suppressed N2O emissions in both soils, and produced contrasting effects on CO2 and NH3 emissions, being enhanced in the agricultural soil while suppressed in the forest soil. 相似文献
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农田改为农林(草)复合系统对红壤CO2和N2O排放的影响 总被引:1,自引:0,他引:1
以鄂南玉米地、紫穗槐/玉米地、香根草/玉米地、紫穗槐林地、香根草草地与撂荒地6种土地利用类型为研究对象,利用静态箱法,对夏玉米生长期间土壤CO2和N2O通量及影响因子进行了测定,研究我国北亚热带丘陵红壤区农田改变为林(草)地和农林(草)复合系统后土壤CO2和N2O排放特征。研究结果表明:(1)土地利用方式改变后,撂荒地土壤CO2排放量明显低于其他5种土地利用类型,但紫穗槐/玉米地、单作玉米地、香根草/玉米地、紫穗槐林地、香根草草地5种土地利用类型之间土壤CO2排放量差异不显著。(2)玉米生长期间,6种不同土地利用方式下,土壤N2O排放总量从高到低依次为紫穗槐/玉米地(508 g·hm-2·a-1)、紫穗槐林地(470 g·hm-2·a-1)、撂荒地(390 g·hm-2·a-1)、香根草/玉米地(373 g·hm-2·a-1)、香根草草地(372 g·hm-2·a-1)、单作玉米地(285 g·hm-2·a-1)。(3)土壤CO2通量与土壤有机碳、土壤微生物生物量碳和土壤含水量无显著相关关系;土壤N2O通量与土壤氮素净矿化率呈显著线性相关,但与土壤无机氮和土壤含水量无显著相关关系。农田改变为农林(草)复合系统可能潜在地增加土壤CO2和N2O排放;农田改变为林(草)地可能潜在地减少土壤CO2排放,增加土壤N2O排放。 相似文献
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Yi Cheng Jing Wang Shen-Qiang Wang Jin-Bo Zhang Zu-Cong Cai 《Biology and Fertility of Soils》2014,50(7):1099-1108
Soil moisture changes, arising from seasonal variation or from global climate changes, could influence soil nitrogen (N) transformation rates and N availability in unfertilized subtropical forests. A 15?N dilution study was carried out to investigate the effects of soil moisture change (30–90 % water-holding capacity (WHC)) on potential gross N transformation rates and N2O and NO emissions in two contrasting (broad-leaved vs. coniferous) subtropical forest soils. Gross N mineralization rates were more sensitive to soil moisture change than gross NH4 + immobilization rates for both forest soils. Gross nitrification rates gradually increased with increasing soil moisture in both forest soils. Thus, enhanced N availability at higher soil moisture values was attributed to increasing gross N mineralization and nitrification rates over the immobilization rate. The natural N enrichment in humid subtropical forest soils may partially be due to fast N mineralization and nitrification under relatively higher soil moisture. In broad-leaved forest soil, the high N2O and NO emissions occurred at 30 % WHC, while the reverse was true in coniferous forest soil. Therefore, we propose that there are different mechanisms regulating N2O and NO emissions between broad-leaved and coniferous forest soils. In coniferous forest soil, nitrification may be the primary process responsible for N2O and NO emissions, while in broad-leaved forest soil, N2O and NO emissions may originate from the denitrification process. 相似文献
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采用实验室静态培养方法,通过氮肥配施不同量纳米碳来探究纳米碳对植烟土壤氮素转化以及N_2O排放的影响。试验在等氮条件下共设置5个处理:CK,硝酸铵(N 200 mg/kg,下同);NC1,硝酸铵+纳米碳(2.5 g/kg);NC2,硝酸铵+纳米碳(5 g/kg);NC3,硝酸铵+纳米碳(10 g/kg);NC4,硝酸铵+纳米碳(15 g/kg)。结果表明:NC3和NC4处理较CK处理显著降低了土壤pH(P0.05);与CK处理相比,NC1、NC2、NC3和NC4处理在培养前期增加了土壤NH_4~+-N含量,相应降低了NO_3~–-N含量;在培养结束时,与CK处理相比,添加纳米碳处理显著降低了无机氮含量,而显著增加了CO_2累积排放量(P0.05);另外,添加纳米碳处理较CK处理增加了N_2O累积排放量,但仅NC4处理与CK处理间差异显著(P0.05),N_2O累积排放量与CO_2累积排放量呈显著正相关关系(R~2=0.50,P0.001)。可见,添加纳米碳能够降低土壤pH和无机氮含量,抑制土壤硝化作用,同时还可以提高微生物活性和增加N_2O排放量。 相似文献
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Moe Shimotsuma Yasuhiro Nakajima Hiroko Akiyama 《Soil Science and Plant Nutrition》2013,59(2):178-184
ABSTRACTLegumes, including hairy vetch (Vicia villosa Roth), are widely used as green manures. They fix nitrogen (N) and provide the N to other crops when they decompose, and thus are considered alternatives for chemical N fertilizers. However, N-rich plant residues, including hairy vetch, are also sources of soil nitrous oxide (N2O) emissions, a greenhouse gas. On one hand, rice (Oryza sativa L. ssp. japonica) husk biochar is widely used as a soil conditioner in Japan and has been reported as a tool to mitigate soil N2O emissions. We conducted a soil core incubation experiment (1.5 months) to compare the N2O emissions during the decomposition of surface-applied hairy vetch (0.8 kg dried hairy vetch m?2 soil) under semi-saturated soil moisture conditions (~100% water-filled pore space (WFPS)), using two soil types, namely Andosol and Fluvisol. Throughout the incubation period, the use of biochar suppressed soil NH4+-N concentrations in Andosol, whereas the effect of biochar on NH4+-N was not clear in Fluvisol. Biochar increased the nitrate (NO3?-N) levels both in Andosol and Fluvisol, suggesting a negative influence on denitrification and/or a positive influence on nitrification. Biochar application did not influence the cumulative N2O emissions. Our study suggests that rice husk biochar is not a good option to mitigate N2O emissions during the decomposition of surface-applied hairy vetch, although this study was performed under laboratory conditions without plants. However, the trends of the inorganic-N concentration changes followed by the addition of hairy vetch and biochar were markedly different between the two soil types. Thus, factors behind the differences need to be further studied. 相似文献
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《Soil Science and Plant Nutrition》2013,59(5):782-788
Abstract An incubation experiment was conducted to examine the effects of the phosphorus (P) application on nitrous oxide (N2O) and nitric oxide (NO) emissions from soils of an Acacia mangium plantation in Indonesia. The soils were incubated with and without the addition of P (Ca[H2PO4]2; 2 mg P g soil)?1) after adjusting the water-filled pore space (WFPS) to 75% or 100%. The P addition increased N2O emissions under both WFPS conditions and NO emissions at 75% WFPS. Some possible mechanisms are considered. First, the P addition stimulated nitrogen (N) cycling, and N used for nitrification and/or denitrification also increased. Second, the P addition could have relieved the P shortage for nitrifying and/or denitrifying bacteria, producing N2O and NO. Our results suggest that the application of P fertilizer has the potential to stimulate N2O and NO emissions from Acacia mangium plantations, at least when soils are under relatively wet conditions. 相似文献
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模拟氮沉降对湿性常绿阔叶次生林土壤碳氮组分和酶活性的影响 总被引:5,自引:4,他引:1
为了研究氮沉降对次生林土壤碳氮组分和酶活性的影响,以华西雨屏区湿性常绿阔叶次生林为对象,从2014年1月起进行野外定位模拟氮沉降试验,分别设置对照(CK,+0 g/(m^2·a))、低氮(LN,+5 g/(m^2·a))和高氮(HN,+15 g/(m^2·a))3个氮添加水平。在氮沉降进行27个月后,按照腐殖质层和淋溶层表层进行取样,测定不同土层土壤总有机碳(TOC)、可浸提溶解性有机碳(EDOC)、易氧化碳(ROC)、全氮(TN)、硝态氮(NO_3^-—N)和铵态氮(NH_4^+—N)含量以及蔗糖酶、脲酶、酸性磷酸酶和多酚氧化酶活性。结果表明:模拟氮沉降显著增加该次生林腐殖质层土壤的TOC和NH_4^+—N含量,显著增加腐殖质层和淋溶层表层土壤的NO_3^-—N含量,腐殖质层土壤C/N显著升高。淋溶层表层土壤TOC、NH_4^+—N、C/N以及2层土壤的EDOC、ROC、TN和NH_4^+—N/NO_3^-—N均无显著影响。2层土壤的多酚氧化酶活性均随着氮添加量的升高而降低,其中淋溶层表层达到显著差异。模拟氮沉降对蔗糖酶、脲酶和酸性磷酸酶活性均无显著影响。腐殖质层中,NH_4^+—N和NO_3^-—N含量与TOC含量存在极显著正相关关系。2层土壤的多酚氧化酶活性均与NO_3^-—N含量呈极显著负相关。结果说明,模拟氮沉降使该次生林中原本较高的腐殖质层土壤TOC含量进一步显著增加,并且促进土壤无机氮的积累,而模拟氮沉降对多酚氧化酶的抑制作用更加有利于土壤有机质的积累。 相似文献
19.
YuHua Kong Mirai Watanabe Hirohiko Nagano Keiji Watanabe Miwa Yashima 《Soil Science and Plant Nutrition》2013,59(5):790-799
Land-use type and nitrogen (N) addition strongly affect nitrous oxide (N2O) and carbon dioxide (CO2) production, but the impacts of their interaction and the controlling factors remain unclear. The aim of this study was to evaluate the effect of both factors simultaneously on N2O and CO2 production and associated soil chemical and biological properties. Surface soils (0–10 cm) from three adjacent lands (apple orchard, grassland and deciduous forest) in central Japan were selected and incubated aerobically for 12 weeks with addition of 0, 30 or 150 kg N ha–1 yr–1. Land-use type had a significant (p < 0.001) impact on the cumulative N2O and CO2 production. Soils from the apple orchard had higher N2O and CO2 production potentials than those from the grassland and forest soils. Soil net N mineralization rate had a positive correlation with both soil N2O and CO2 production rates. Furthermore, the N2O production rate was positively correlated with the CO2 production rate. In the soils with no N addition, the dominant soil properties influencing N2O production were found to be the ammonium-N content and the ratio of soil microbial biomass carbon to nitrogen (MBC/MBN), while those for CO2 production were the content of nitrate-N and soluble organic carbon. N2O production increased with the increase in added N doses for the three land-use types and depended on the status of the initial soil available N. The effect of N addition on CO2 production varied with land use type; with the increase of N addition doses, it decreased for the apple orchard and forest soils but increased for the grassland soils. This difference might be due to the differences in microbial flora as indicated by the MBC/MBN ratio. Soil N mineralization was the major process controlling N2O and CO2 production in the examined soils under aerobic incubation conditions. 相似文献