首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到17条相似文献,搜索用时 140 毫秒
1.
为了评价林下侵蚀劣地碳氮提升对短期恢复管理措施的响应,选择基于最小可检测变化(minimum detectable change,MDC)设计的土壤有机碳(SOC)、全氮(TN)和碱解氮(AN)随时间变化的随机分层采样方法,用以消除林下土壤碳氮的空间变异性。以南方红壤低山丘陵区马尾松林下侵蚀劣地为对象,共设置7个处理:无恢复措施(CT)、乔草+鱼鳞坑(FG)、乔灌+鱼鳞坑(FS)、乔灌草+鱼鳞坑(FGS)、乔草+小水平沟(FGP)、乔灌+小水平沟(FSP)、乔灌草+小水平沟(FGSP)。结果表明:试验进行1.5年后,各处理的总植被盖度较试验前显著增加,增加幅度为7%~50%,其中草灌植被盖度增加尤为明显。基于MDC结果,除FG、FS处理外,其余处理均可以检测到SOC的变化;除FG外,其余处理均可以检测到TN的变化,而所有处理均可以检测到AN的变化。与试验前相比,各恢复措施下SOC、TN和AN含量的增量分别为0.10~2.08 g/kg、0.02~0.13 g/kg和8.54~25.06 mg/kg。SOC、TN和AN的净增量百分数分别为34%~101%,35%~83%和14%~82%;SOC的净增量大小排序为FGSPFGFGPFGSFSPFS;而TN的净增量表现为FSFGSFGSPFGPFSPFG。小水平沟区组对SOC、TN和AN的增加明显高于鱼鳞坑区组。近地表草灌植被盖度是SOC、TN和AN提升的关键因素。本土先锋草灌植被与小水平沟复合配置措施是林下侵蚀劣地快速增碳固氮的有效措施,研究结果可为红壤林下侵蚀劣地恢复治理提供技术支撑。  相似文献   

2.
[目的]阐明晋西黄土区典型人工植被类型对球囊霉素相关土壤蛋白(GRSP)和团聚体稳定性的影响,以及两者之间的关系,为黄土高原地区人工植被建设与管理提供科学依据。[方法]选取晋西三川河流域4种典型人工植被(苜蓿、刺槐、侧柏和核桃),以农地为对照,分析0—100cm土层中GRSP组分、有机碳(SOC)和团聚体稳定性指标在不同植被类型下的分布差异及其相关性。[结果]不同植被类型下易球囊霉素(EE-GRSP)、总球囊霉素(T-GRSP)以及两者的比值在0—30cm土层存在显著差异,均以核桃地最高,而苜蓿地较低。不同植被下EE-GRSP/SOC和T-GRSP/SOC均随着土层深度增加而增加,分别为1.78~6.77,4.07~19.11。与农地相比,侧柏和苜蓿地分别增加了39.67%,36.62%的EE-GRSP/SOC以及39.25%和46.70%的T-GRSP/SOC,而核桃分别减少了31.07%和36.93%。平均重量直径与T-GRSP和SOC呈显著正相关关系,而与EE-GRSP/SOC呈显著负相关关系(p0.05)。[结论]不同人工植被对表层土壤GRSP的组分有明显影响,土壤团聚体稳定性不仅与GRSP的组分有关,也与其对SOC的贡献有重要关系。  相似文献   

3.
在四川丘陵区紫色土上进行田间试验,以无物料还田为对照,对比分析了蚕豆秸秆、油菜秸秆、猪粪3种物料还田对夏玉米吐丝期和收获期0—20,20—40cm土层土壤有机碳、全氮、微生物量碳氮含量及微生物熵的影响,以期为农业废弃有机物料的综合利用及四川丘陵区土壤质量的提升提供理论参考。结果表明:(1)尽管有机物料还田于0—20cm土层中,0—20,20—40cm土层土壤有机碳(SOC)、全氮(TN)、微生物量碳(SMBC)、微生物量氮(SMBN)含量均受到有机物料的深刻影响。各处理0—20cm土层SOC、TN、SMBC、SMBN含量均显著高于20—40cm土层,且上下2层土壤SOC、TN、SMBC和SMBN含量在生育时期间均表现为吐丝期>收获期。(2)在2个生育时期,3种物料还田均能提高0—20,20—40cm土层SOC、TN、SMBC、SMBN含量。与对照相比,物料还田处理的SOC、TN、SMBC、SMBN含量分别提高2.6%~141.2%,1.9%~33.0%,5.1%~114.7%,41.5%~98.7%,其中收获期各处理0—20,20—40cm土层SOC、SMBC、SMBN均表现为油菜秸秆>蚕豆秸秆>猪粪>对照,TN表现为蚕豆秸秆>猪粪>油菜秸秆>对照。(3)各处理SMBC/SMBN、qMB、SMBN/TN分别为3.74~10.53,0.86%~2.19%,1.01%~3.41%,且物料还田降低SMBC/SMBN,提高土壤qMB和SMBN/TN值。相关分析表明,SMBC、SMBN与SOC、TN之间均存在极显著正相关关系。因此,农业生产中可通过物料还田提供给微生物足够的碳氮营养,提高土壤SMBC、SMBN、SOC、TN含量和qMB值,维持较高的农田生产力,提升土壤质量,但具体施用物料时还需寻求土壤肥力提升、玉米产量增加以及环境效益之间的平衡。  相似文献   

4.
不同施肥处理对球囊霉素土壤蛋白含量的影响   总被引:1,自引:0,他引:1  
球囊霉素是丛枝菌根真菌分泌的一种疏水性蛋白,通过研究不同施肥处理对棕壤中Bradford反应性球囊霉素土壤蛋白(GRSP)含量的影响以及GRSP与土壤有机碳之间的关系表明:不同施肥处理显著影响土壤中GRSP的含量,无机肥、有机肥以及有机-无机肥配施均显著增加农田土壤总GRSP(T-GRSP)和易提取GRSP(EE-GRSP)的含量,以有机-无机肥配施效果最好。与CK和单施NPK处理比较,有机肥施用提高土壤T-GRSP在土壤有机质(SOM)中的比例,表明有机肥促进GRSP在土壤有机质中的累积,提高GRSP对土壤有机质的贡献。同时,不同施肥处理GRSP含量与土壤有机碳(SOC)含量呈极显著相关关系。  相似文献   

5.
以黄土高原南部半湿润易旱区已进行17年的田间定位试验为研究对象,研究了不同培肥措施(不施肥、施用氮磷钾及氮磷钾与有机肥配合施用)下两种种植制度(一年1熟及一年两熟)和撂荒对土壤微生物量碳、氮(SMBC、SMBN)及可溶性有机碳、氮(SOC、SON)等含量的影响.结果表明,与一年1熟的小麦一休闲种植制度相比,一年两熟小麦一玉米轮作提高了0~10 cm土层SMBC、SMBN、有机碳(TOC)、全氮(TN)和土壤SOC、SON的含量,而对10~20 cm土层上述测定指标影响不大.与不施肥(CK)或单施化肥处理(NPK)下小麦-休闲和小麦-玉米轮作方式相比,撂荒处理显著提高了0~10 cm土层各测定指标的含量.不同培肥措施相比,氮磷钾配施有机肥显著提高了0~10 cm、10~20 cm土层SMBC、SMBN含量;NPK处理0~10 cm土层SMBN含量显著增加,10~20 cm土层SMBN和0~10 cm、10~20 cm土层SMBC含量增加但未达显著水平.不同培肥措施和种植制度对SMBC/TOC和SMBN/TN的比例无明显影响.  相似文献   

6.
土壤微生物和生物化学性质是农业土壤生产力的重要指标.该文研究了湖南省双季稻种植区不同生产力水稻土微生物种群数量和生物化学性质的差异.不同生产力水稻土样品采自湖南省东部、中部和西北部8个水稻主产县,测定了高产、中产和低产水稻土的微生物种群数量、微生物生物量C(SMBC)、微生物生物量N(SMBN)、土壤呼吸、代谢熵(qCO2)、脲酶、磷酸酶、转化酶、脱氢酶、土壤有机C(SOC)、全N(TN)、全P(TP)、全K(TK)、有效N(AN)、速效P(AP)、速效K(AK)和稻谷与稻草产量.结果表明,高产水稻土的细菌、真菌、放线菌数量和微生物生物量C、N与中产水稻土无明显差异.SMBC、SMBN含量和土壤脲酶、转化酶、脱氢酶活性与细菌、真菌和放线菌的变化规律基本相似.由于湖南省植稻区施用磷肥有近50年历史,土壤磷素含量较高,导致不同生产力水稻土之间的磷酸酶活性没有差异.细菌和放线菌与SOC、TN、TK、AN含量之间相关性最好.脲酶和转化酶活性与土壤SOC、SMBC、SMBN、TN和AN含量之间的相关性最好.高产水稻土与中产水稻土之间在微生物性质上差异很小,中产水稻土只要加强田间管理措施,可以达到高产水稻土的产量目标.目前低产水稻土的微生物性质和生物化学性质较差,应注意有机肥料和无机肥料的合理施用,重视低产水稻土的改良,提升这类土壤的生物质量.  相似文献   

7.
秸秆与氮肥不同配比对红壤微生物量碳氮的影响   总被引:9,自引:2,他引:7  
【目的】 秸秆碳氮比是影响其养分释放和还田利用的主要因素之一。秸秆还田条件下,如何合理施用氮肥是秸秆利用的关键问题。研究玉米秸秆还田配施不同量氮肥后土壤微生物特性的变化,对于指导秸秆还田和培肥土壤有重要意义。 【方法】 在中国农业科学院衡阳红壤实验站旱地试验田进行尼龙袋大田填埋试验,供试土壤为红壤。尼龙袋装土200 g (以风干土计),共设置6个处理:CK、低量尿素0.157 g (N1)、高量尿素0.939 g (N2)、玉米秸秆9 g (S)、玉米秸秆 + 低量尿素 (SN1)、玉米秸秆 + 高量尿素 (SN2)。S、SN1和SN2处理中混合物的碳氮比分别为53∶1、37∶1、15∶1。填埋后分别于7、14、21、28、49和150 d取样,分析不同碳氮比秸秆还田后土壤有机碳 (SOC)、微生物生物量碳和氮 (SMBC和SMBN)、微生物熵 (SMBC/SOC) 及微生物量碳氮比 (SMBC/SMBN) 等随时间的变化及处理间差异。 【结果】 SMBC和SMBN均随时间先增加后降低,分别在21 d和14 d达到最大值。还田150 d时与CK相比,秸秆还田各处理SMBC增加了4~5倍,SMBN增加了6~8倍。S、SN1和SN2处理的SMBC 6次取样的平均值分别为1425、1379和1462 mg/kg,约为其他处理的10倍;SMBN分别为172、181和193 mg/kg,约为其他处理的8倍;微生物熵分别为3.57、3.41和3.57,约为其他处理的2.8倍,S、SN1和SN2处理间差异不显著。N1、N2的SMBC/SMBN显著低于S处理。在28 d前,S、SN1和SN2处理间SMBC/SMBN值差异不显著,28 d后S处理显著高于SN1和SN2;150 d时S处理SMBC/SMBN值约为10,SN1和SN2处理约为6。 【结论】 玉米秸秆还田显著提高了SMBC、SMBN和微生物熵。秸秆还田和氮肥施用均会降低SMBC/SMBN值,且氮肥用量越大比值越低。当秸秆还田时,将碳氮比调整到37∶1不能满足微生物对氮的需求,因此在南方红壤秸秆还田时要补充氮素。   相似文献   

8.
球囊霉素或球囊霉素类相关蛋白(glomalin-related soil protein,GRSP)是丛枝菌根真菌(AMF)分泌的一种疏水性蛋白。为研究氮沉降对土壤GRSP的影响,选取了黄土高原典型地带性植物白羊草(Bothriochloa ischaemum)为研究对象,采用小车模拟小区试验,通过氮添加来模拟氮沉降,共设置3个氮添加浓度N_1(2.5g/m~2)、N_2(5g/m~2)和N_3(10g/m~2),以裸地(LD)和不添加氮处理CK(0g/m~2)为对照。结果表明:不同浓度氮添加后,土壤中总球囊霉素(Total glomalin,T-GRSP)含量呈现先增加后降低的趋势,但变化未达到显著水平,而易提取球囊霉素(Easily extractable glomalin,EE-GRSP)的含量变化在N_3时显著降低(p0.05)。冗余分析表明SOC,C/N、地下地上生物量是影响土壤GRSP的主要因素。研究从土壤GRSP角度分析了氮添加对土壤活性物质的影响,有利于揭示未来全球氮沉降背景下土壤质量的变化,加深对土壤生态变化过程的认识。  相似文献   

9.
以黄土高原南部地区的两个定位试验为基础,研究了旱地不同栽培和施肥模式对土壤微生物量碳、氮和可溶性有机碳、氮的影响.结果表明,秸秆覆盖显著提高土壤微生物量氮(SMBN)含量,地膜覆盖使SMBN含量显著降低;秸秆和地膜覆盖显著降低小麦拔节期和灌浆期土壤可溶性有机氮(SON)含量.适量施用化学氮肥(120kg/hm2)有利于小麦生长后期SMBN含量的升高,而过量施用(240 kg/hm2)显著降低SMBN含量.与不施肥处理相比,土地经长期撂荒后0-10 cm土层SMBC,SMBN,SOC和SON含量显著提高;氮磷钾配施有机肥显著提高小麦各生育期0-10,10-20 cm土层SMBC,SMBN,SOC和SON的含量;单施氮磷钾肥对土壤SMBC,SMBN含量无明显影响,提高土壤SOC,SON的平均含量.土壤SMBC,SMBN,SOC和SON含量两两之间呈极显著正相关关系,四者含量与土壤有机碳、全氮含量间的正相关关系也达显著或极显著水平.  相似文献   

10.
为研究坡向对土壤球囊霉素相关蛋白(GRSP)的影响,选取了3个弃耕年限相同、立地条件相似,仅坡向不同的天然草地为试验地,坡向分别为阳坡(S15°W)、半阳坡(N75°W)、阴坡(N57°E)。首先对3个坡向的典型植物群落进行了植被调查,然后采集了优势物种的根际土与非根际土并进行测定。结果表明:不同坡向土壤GRSP含量整体表现为阳坡半阳坡阴坡,其中阴坡土壤T-GRSP含量较阳坡、半阳坡显著减少;不同物种对土壤GRSP含量无显著差异;T-GRSP呈现较强的根际效应,EE-GRSP则较弱。研究表明GRSP与坡向呈负相关,与物种和根际作用正相关,根际作用强于物种。  相似文献   

11.
Glomalin-related soil protein (GRSP), a glycoprotein of arbuscular mycorrhizal fungi (AMF) secreted into soil, governs the aggregate stability, but the role of GRSP in soil and plant water is sparsely studied. The 24-week-old red tangerine (Citrus tangerina) inoculated with Glomus etunicatum and G. mosseae were subjected to a soil drying for 12 days as soil water deficit (SWD). Length of SWD significantly reduced mycorrhizal colonization, soil hyphal length, and leaf and soil water potential (Ψ), but increased total GRSP (T-GRSP), easily extractable GRSP (EE-GRSP), and proportion of water-stable aggregates (WSAs) in >0.25 mm size, irrespective of AMF source. The AMF-inoculated seedlings showed significantly higher T-GRSP, EE-GRSP, and leaf/soil Ψ than non-AMF seedlings during SWD. A significantly positive correlation was observed for mycorrhizal colonization versus leaf or soil Ψ, and hyphal length versus leaf Ψ, suggesting that root intra- and extra-radical hyphae participated in water transport. Interestingly, in GRSP fractions, only T-GRSP was significantly positively correlated with 0.25–1 and >0.25 mm WSA and negatively with leaf and soil Ψ. These results revealed a strong glue function of T-GRSP (not EE-GRSP and hyphae) to alter the proportional distribution of WSA size, thereby aiding toward prevention of soil water loss for improving soil–plant water relations.  相似文献   

12.
南京典型利用方式土壤中球囊霉素含量及剖面分布特征   总被引:2,自引:0,他引:2  
阙弘  葛阳洋  康福星  凌婉婷 《土壤》2015,47(4):719-724
采用Brad-ford染色法研究了南京市5种典型利用方式土壤不同土层中(0~10、10~20、20~40 cm)球囊霉素的含量。结果表明:土壤中总球囊霉素含量为1.96~3.12 mg/g,占土壤有机碳的12.5%~29.0%,所占比例随土壤有机碳含量的增加而降低。林地和草地土壤中球囊霉素和有机碳的含量均高于3种耕作土壤(水稻田、茶园土和菜园土)。随着土层深度(0~40 cm)的增加,5种不同利用方式土壤中总球囊霉素和有机碳的含量均减小;与其他土层相比,0~10 cm土层总球囊霉素和有机碳含量均最大。耕作土壤中易提取球囊霉素更易于向总球囊霉素转化。发现5种土地利用方式下土壤中总球囊霉素含量与土壤有机碳含量极显著正相关,与土壤p H显著负相关;易提取球囊霉素与土壤有机碳含量极显著负相关。总球囊霉素和易提取球囊霉素可作为评价土壤丛枝菌根真菌活性和土壤质量的重要指标。  相似文献   

13.
According to the economy theory, plants should preferentially allocate photosynthate to acquire below-ground resources under elevated atmospheric carbon dioxide (eCO2) but decrease below-ground C allocation when nitrogen (N) is sufficient for plant growth. Arbuscular mycorrhizae (AM) represent a critical mechanism of below-ground nutrient acquisition for plants. The dynamics of arbuscular mycorrhizal fungi (AMF) could therefore reflect the response of plant C allocation under eCO2 and N addition. We examined the responses of glomalin-related soil protein (GRSP) to eCO2 (approximately 700 μmol mol−1 CO2) and/or N addition (100 kg N ha−1 yr−1 as NH4NO3) in a modeled subtropical forest to better understand its potential influence on soil C storage. We hypothesized that GRSP would increase under eCO2 and decrease under N addition. Furthermore, the positive effects of eCO2 on GRSP would be offset by extra N addition, and GRSP would remain unchanged under combined eCO2 and N addition. Our results showed that the mean concentrations of easily extractable GRSP (EE-GRSP) and total GRSP (T-GRSP) were 0.35 ± 0.05 and 0.72 ± 0.13 mg C cm−3, respectively, which accounted for 2.76 ± 0.53% and 5.67 ± 0.92% of soil organic carbon (SOC) in the 0–10 cm soil layer. Elevated CO2 significantly increased T-GRSP by 35.02% but decreased EE-GRSP by 5.09% in the top 10 cm soil layer. The opposite responses of T-GRSP and EE-GRSP to eCO2 might result from an unchanged photosynthate investment to AMF with possible changes in their decomposition rates. The effect of N on GRSP was contrary to our hypothesis, i.e., there was a 1.72%–48.49% increase in T-GRSP and a slightly increase in EE-GRSP. Both EE-GRSP and T-GRSP concentrations increased under the combination of eCO2 and N addition, which was inconsistent with our hypothesis. The significant increase of EE-GRSP under the combination of eCO2 and N addition was partly caused by more rapid plant growth and reduced microbial diversity, and the marginal increase of T-GRSP indicated that the interaction between eCO2 and N addition offset their independent effects. In addition, the relatively higher accumulation ratios of GRSP (22.6 ± 13.6%) compared with SOC (15.9 ± 9.4%) indicated that more rapid GRSP deposition in the soil might accelerate SOC accumulation under eCO2 and N addition. Our results will improve the understanding of the functioning of GRSP in soil C sequestration under global environmental change scenarios.  相似文献   

14.
通过设置在甘肃省定西市李家堡镇的保护性耕作措施长期定位试验,共设4个处理(T:传统耕作;NT:免耕无覆盖;TS:传统耕作+秸秆还田;NTS:免耕+秸秆覆盖),采用春小麦豌豆双序列轮作(即小麦→豌豆→小麦和豌豆→小麦→豌豆,本文中所指春小麦地、豌豆地分别指2008年种植春小麦、豌豆的轮作次序),于2008年3月中旬对春小麦、豌豆双序列轮作下的土壤有机碳、全氮、土壤微生物量碳及土壤微生物量氮含量进行了采样测定。结果表明,经过7a的轮作后,两种轮作次序下,0-30cm土层中土壤有机碳、全氮、土壤微生物量碳、土壤微生物量氮含量均有在免耕+秸秆覆盖、传统耕作+秸秆还田处理较免耕不覆盖、传统耕作处理高的趋势,且其含量均随着土壤深度的增加而降低。其中,土壤微生物量碳含量在两种轮作次序下的排序均为:免耕+秸秆覆盖(NTS)〉传统耕作+秸秆还田(TS)〉免耕不覆盖(NT)〉传统耕作(T);而土壤微生物量氮含量在春小麦地和豌豆地的排序则分别表现为:免耕+秸秆覆盖(NTS)〉传统耕作+秸秆还田(TS)〉传统耕作(T)〉免耕不覆盖(NT)和免耕+秸秆覆盖(NTS)〉传统耕作+秸秆还田(TS)〉免耕不覆盖(NT)〉传统耕作(T)。同时,微生物量碳、微生物量氮与有机碳和全氮均呈显著正相关,说明提高土壤有机质、全氮含量的保护性耕作模式有利于土壤微生物量碳与氮的积累。  相似文献   

15.
Jia  Shuxian  Liu  Xiaofei  Lin  Weisheng  Zheng  Yong  Li  Jianwei  Hui  Dafeng  Guo  Jianfen 《Journal of Soils and Sediments》2022,22(3):931-941
Purpose

Glomalin-related soil protein (GRSP) is an essential component of soil organic C for maintaining soil quality and structure and plays a critical role in soil carbon (C) sequestration. However, how GRSP changes under nitrogen (N) deposition remains poorly understood.

Materials and methods

We assessed total GRSP (T-GRSP) and easily extractable GRSP (EE-GRSP) under a control (no N input), low N addition (LN, 40 kg N ha?1 year?1), and high N addition (HN, 80 kg N ha?1 year?1) treatments in 2015 and 2016 in a Chinese fir (Cunninghamia lanceolata) plantation in the subtropical China. We also analyzed soil properties contents and explored the stoichiometric ratios of soil organic C (SOC), total N (TN), and total phosphorus (TP) with GRSPs.

Results

Compared to the control, both T-GRSP and EE-GRSP were significantly reduced under the HN treatment, but had no significant difference under the LN treatment. The ratio of T-GRSP and EE-GRSP was reduced by the N addition. Soil organic C (SOC) and dissolved organic C (DOC) were significantly affected by N addition treatments. The ratios of GRSP-C to SOC and of EEGRSP-C to SOC ranged from 6.29 to 16.07% and 1.34 to 3.52%, respectively. T-GRSP and EE-GRSP were positively correlated with SOC/TN ratio, but negatively correlated with soil TN/TP and SOC/TP ratios.

Conclusion

Our results indicated that the GRSP reductions under N deposition in soil are mediated by soil C, N, and P stoichiometry, and particularly, the reduction of EE-GRSP by DOC. This study improved our mechanistic understanding of dynamics of GRSPs under increasing N enrichment in subtropical plantation ecosystems.

  相似文献   

16.
[目的]研究不同追施尿素量对麦后复种油菜生物产量和耕层土壤有机碳、土壤微生物量碳氮及碳库管理指数的影响,为麦后复种油菜尿素施用量提供依据。[方法]在古浪县进行小区试验,设置5个试验水平:追施尿素0,90,120,150,180kg/hm2。[结果]追肥可提高麦后复种油菜的生物产量;土壤有机碳、微生物量碳、微生物氮以及碳库管理指数均随追肥量的增加呈抛物线型变化的趋势;碳库指数和碳库管理指数的变化趋势同有机碳的变化趋势;有机碳、微生物量碳与碳库管理指数显著相关,有机碳与碳库管理指数极显著相关,微生物量碳与有机碳含量虽呈现正相关关系,但未达到显著相关性。[结论]综合油菜生物产量和土壤微生物量等指标,古浪县麦后复种油菜的施肥量以追施尿素120~150kg/hm2为宜。  相似文献   

17.
Glomalin is a metal-sorbing glycoprotein excreted by arbuscular mycorrhizal fungi (AMF). One method of estimating glomalin in soils is as glomalin-related soil protein (GRSP). In this study the role of GRSP in sequestering Pb and Cd was investigated in an in situ field experiment. The effect of metal sequestration on the subsequent decomposition of GRSP was also investigated. GRSP was determined using the Bradford method as total glomalin-related soil protein (T-GRSP) and as easily extractable glomalin-related soil protein (EE-GRSP). After 140 days, GRSP bound Pb accounted for 0.21–1.78% of the total Pb, and GRSP bound Cd accounted for 0.38–0.98% of the total Cd content in the soil. However when compared on a soil organic matter (SOM) basis, only 4% of the Pb or Cd was bound to the GRSP fraction of the SOM compared with 40–54% of the Pb or Cd bound to the humin and fulvic acids in the SOM fraction. In soils contaminated with the highest levels of Pb and Cd, the T-GRSP (EE-GRSP) decomposition after 140 days was reduced by 8.0 (6.6)% and 7.0 (7.5)%, respectively, when compared with the controls. In the high Pb or Cd treatment groups we found that the fraction of metal bound to GRSP increased even though the total GRSP content declined over time. The mass ratio between Pb and GRSP-carbon changed from 2.3 to 271.4 mg (100 g)−1 in all Pb levels soil, while with the high-Cd treatment group the mass ratio between Cd and GRSP-carbon (0.36 mg (100 g)−1) was higher than the mass ratio seen with Cd-bound humic acid fractions. Our in situ field study shows that while GRSP does bind Pb and Cd, in the soils we investigated, the levels are insignificant compared to soil organic matter such as humic and fulvic acids.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号