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四川盆地亚热带常绿阔叶林表层土壤氮截留与淋溶流失特征 被引量:4
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作者 王滨 吴福忠 +3 位作者 杨万勤 李俊 彭艳 曹瑞 《水土保持学报》 CSCD 北大核心 2015年第6期45-52,共8页
以四川盆地典型桢楠(Phoebe zhennan)和马尾松(Pinus massoniana)人工林为研究对象,于2013年12月至2014年12月,采用原位培养法监测了雨季(3个时期)和旱季(2个时期)5个关键时期土壤N截留和淋溶输出特征。结果表明:马尾松人工林... 以四川盆地典型桢楠(Phoebe zhennan)和马尾松(Pinus massoniana)人工林为研究对象,于2013年12月至2014年12月,采用原位培养法监测了雨季(3个时期)和旱季(2个时期)5个关键时期土壤N截留和淋溶输出特征。结果表明:马尾松人工林土壤的N截留和淋溶输出总量分别为17.82,26.95kg/(hm2·a),桢楠人工林土壤的N截留和淋溶输出总量分别为8.90,17.98kg/(hm2·a),2种人工林土壤均表现出明显的N截留作用,且硝态氮和水溶性有机氮的输入与输出量显著高于铵态氮和亚硝态氮(P〈0.01)。此外,2种人工林土壤N输入和输出均表现出显著的季节性差异,59.64%~77.14%的N输入过程都发生于旱季末期和雨季早期,且这2个时期的土壤N淋溶输出量分别占全年的44.86%~52.70%。2种人工林土壤在旱季主要表现为N截留效应,而雨季主要表现为N流失。相关性分析结果表明,除桢楠人工林的铵态氮和马尾松人工林的硝态氮外,2种人工林土壤N库的其余N组分淋溶输出量与降水量呈极显著正相关(P〈0.01),土壤对可溶性无机氮的截留量则与降水量呈负相关。总体而言,桢楠和马尾松人工林土壤N输入、输出和截留作用主要发生于旱季末期,且以硝态氮和水溶性有机氮为主。 展开更多
关键词 土壤截留 土壤输入 土壤氮淋溶 桢楠人工林 马尾松人工林 常绿阔叶林
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降水变化对科尔沁沙地樟子松人工林土壤氮矿化和淋溶的影响 被引量:2
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作者 葛志强 赵姗宇 +2 位作者 林贵刚 孙学凯 胡亚林 《生态学报》 CAS CSCD 北大核心 2020年第18期6564-6572,共9页
为研究降水量减少对沙地森林土壤氮循环过程的影响,以科尔沁沙地15年生樟子松人工林为研究对象,野外模拟不同降水量(自然降水、减少30%和50%)对沙地樟子松人工林土壤无机氮(SIN)含量、氮矿化速率和淋溶动态的影响。研究结果发现,沙地樟... 为研究降水量减少对沙地森林土壤氮循环过程的影响,以科尔沁沙地15年生樟子松人工林为研究对象,野外模拟不同降水量(自然降水、减少30%和50%)对沙地樟子松人工林土壤无机氮(SIN)含量、氮矿化速率和淋溶动态的影响。研究结果发现,沙地樟子松人工林SIN主要以硝态氮形态存在,模拟降水减少降低土壤硝态氮含量(P<0.05)和硝态氮/SIN值(P<0.001),而增加土壤铵态氮含量(P<0.05)。与自然降水相比,降水减少降低土壤净硝化速率和净矿化速率(P=0.002),但不同降雨处理的土壤净氨化速率差异不显著(P=0.86)。科尔沁沙地樟子松人工林土壤以硝态氮淋溶为主,不同降雨处理土壤硝态氮淋溶量差异不显著(P=0.09),但模拟降水减少降低土壤铵态氮淋溶(P=0.04)。此外,沙地樟子松人工林SIN含量、净氮矿化速率和淋溶量具有明显月动态特征,与降雨月动态规律基本一致。降水处理和采样时间对SIN含量和净氮矿化速率具有显著交互作用,但土壤氮淋溶量的交互作用不显著。可见,降水变化能够显著影响科尔沁沙地樟子松人工林土壤氮有效性、氮矿化速率和淋溶等过程,未来干旱加剧可能降低科尔沁沙地樟子松人工林土壤氮的可利用性。 展开更多
关键词 科尔沁沙地 樟子松人工林 减少降水 土壤矿化 土壤氮淋溶
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森林土壤碳、氮淋失过程及其形成机制研究进展 被引量:17
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作者 方华军 程淑兰 于贵瑞 《地理科学进展》 CSCD 北大核心 2007年第3期29-37,共9页
大气氮沉降对森林生态系统碳截存和损耗过程的影响已引起广泛关注,但对沉降氮在森林生态系统中的去向、增氮对土壤中碳/氮转化过程的影响以及土壤氮饱和前后土壤渗漏液中溶解性有机碳(DOC)和溶解性有机氮(DON)动态等方面的研究还不够深... 大气氮沉降对森林生态系统碳截存和损耗过程的影响已引起广泛关注,但对沉降氮在森林生态系统中的去向、增氮对土壤中碳/氮转化过程的影响以及土壤氮饱和前后土壤渗漏液中溶解性有机碳(DOC)和溶解性有机氮(DON)动态等方面的研究还不够深入。本文论述了近年来国内外在土壤氮饱和及土壤碳、氮淋溶领域的最新研究进展,从系统论的角度阐述土壤氮饱和过程及内涵;通过论述DOC和DON含量及其结构组成变化来揭示其对增氮/氮沉降的内在响应机理;论述了增氮对土壤无机氮转化的影响以及生物和非生物因素对沉降氮固持的贡献。指出土壤氮饱和为土壤中的有效氮随时间增加超过了土壤中生物和非生物的持留能力,导致土壤氮的净矿化、净硝化、NO-3流失以及土壤酸化等过程发生一系列非线性变化。初步认为土壤中DOC和DON对增氮的不同响应归因于氮素饱和过程的三个不同阶段。对于特定的生态系统来说,需要清楚地认识土壤氮素矿化、硝化、反硝化和固持等过程,才能明晰土壤氮素状态以及随时间的演变。另外,指出在上述三个研究领域中存在的问题,并提出拟解决的途径以及未来的可能研究方向,以期对该领域的研究提供参考。 展开更多
关键词 沉降 土壤饱和 溶解性有机质 土壤氮淋溶 土壤转化
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Nitrogen recovery and nitrate leaching of controlled release nitrogen fertilizer in irrigated paddy soil 被引量:3
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作者 郑圣先 聂军 +1 位作者 戴平安 郑颖俊 《Agricultural Science & Technology》 CAS 2004年第3期2-10,共9页
Ordinary high nitrogen fertilizer often results in nitrate (NO3--N) leaching and low recovery. Microplot and field plot experiments were conducted to determine the effect of controlled release nitrogen fertilizer (CRN... Ordinary high nitrogen fertilizer often results in nitrate (NO3--N) leaching and low recovery. Microplot and field plot experiments were conducted to determine the effect of controlled release nitrogen fertilizer (CRNF) on reco very and nitrate leaching on paddy soils. During two early rice cropping seasons (2002 and 2003), a single basal application of CRNF at 90 kg N ha-1 increased grain yields by 7.7%to 11.6%compared with two applications of urea. Estimated by the difference method fertilizer N recovery of CRNF (mean 76.3%) was 38.9 pe rcentage point higher than that of urea (mean 37.4%); estimated by 15N isotope method (mean 49.6%) CRNF (mean 67.1%) was 35.9 percentage point higher than ur ea (mean 31.2%). NO3--N leaching losses were 9.19 and 6.70 kg ha-1 for urea and CRNF, respectively. NO3--N leaching during the early rice cropping season was 27.1 %lower from CRNF than from two applications of urea. These losses repr esent 10.2%and 7.4%of applied urea-N and CRNF-N. Results from this study ind icate that CRNF improves N recovery and reduces NO3--N leaching and increases rice yield. 展开更多
关键词 controlled release nitrogen fertilizer nitrogen recovery nitrate leaching rice yield
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Soil NH_4^+ Fixation and Fertilizer N Recovery as Affected by Soil Moisture and Fertilizer Application Methods 被引量:6
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作者 TONGYan-Ani O.EMTERYD +1 位作者 H.GRIP LUDian-Qing 《Pedosphere》 SCIE CAS CSCD 2004年第2期247-252,共6页
Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed i... Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed in the laboratory and in a glass shelter,respectively,by using ammonium bicarbonate (NH4HCO3). The laboratory closed incubation box experiment was conducted using the Luvisol to study NH4+ fixation rate at soil moisture levels of 10.1%,22.7% and 35.3% water filled pore space (WFPS). The fixed NH4+-N increased dramatically to 51% and 66%,67% and 74%,and 82% and 85% 1,2 and 36 h after fertilizer incorporation at moisture levels of 10.1% and 22.7% WFPS and 35.3%WFPS,respectively. The rapid NH4+ fixation rates at all moisture levels could help prevent NH4+ losses from ammonia volatilization. In the glass shelter pot experiment,N fertilizer was applied by either banding (in a concentrated strip)or incorporating (thoroughly mixing) with the Entisol and the Luvisol. An average of 74.2% of the added N fertilizer was recovered 26 days after application to the Luvisol,while only 61.4% could be recovered from the Entisol,due to higher NH4+ fixation capacity of the Luvisol. The amount of fixed NH4+ decreased with increasing WFPS. The amount of fixed NH4+ in the incorporated fertilizer treatment was,on average,10% higher than that in the banded treatment.Higher NH4+ fixation rates could prevent N loss and thus increase N recovery. The results from the Luvisol showed lower nitrogen recovery as soil moisture level increased,which could be explained by the fact that most of the fixed NH4+ was still not released when the soil moisture level was low. When the fertilizer was incorporated into the soil,the recovery of N increased,compared with the banded treatment,by an average of 26.2% in the Luvisol and 11.2% in the Entisol,which implied that when farmers applied fertilizer,it would be best to mix it well with the soil. 展开更多
关键词 fertilizer application N recovery NH4+ fixation soil moisture
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