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1.
《Land Degradation u0026amp; Development》2017,28(2):664-672
In previous studies, the rate of soil carbon (C) sequestration decreased with increasing age of post‐mining soils. It was also shown to depend on plant biomass and earthworm bioturbation. Here, a soil transplant experiment was used to determine whether this decrease is caused by soil C saturation or other factors (such as bioturbation and litter input). Soils collected on 15‐, 25‐ and 50‐year‐old successional sites, dominated by willow (Salix caprea L.) and birch (Betula pendula Roth), and on a 50‐year‐old site reclaimed by the planting of alder (Alnus glutinosa L.) were placed in plastic boxes that were accessible to soil macrofauna. The boxes were buried in the 50‐year‐old reclaimed site and supplemented with either alder litter or successional (willow and birch) litter. Soil C content and soil C fractions (hot water C, particulate organic C, particulate organic C bound in aggregates and C bound to mineral soil) were studied. After 1 year, the C content increased by 2–5%, but there was no effect of soil source or litter type. For all C fractions, the relationships between change in C content and initial C content were described by bell‐shaped curves. Easily available C fractions were saturated earlier than more recalcitrant fractions. Despite these saturation tendencies in individual soil organic matter pools, the soil was evidently far from saturation after 50 years of soil development. The decrease in C sequestration with soil age previously observed for this soil was probably caused by a decrease in litter input rather than by C saturation. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
2.
Tao Zhang Bing Song Guangxuan Han Huili Zhao Qiuli Hu Ying Zhao Haojie Liu 《Land Degradation u0026amp; Development》2023,34(11):3340-3349
The reclamation of coastal wetlands for agriculture has expanded considerably over the last 40 years in China. Wetland reclamation could substantially alter soil properties, but so far, a systematic analysis of the changes in soil chemical elements after reclamation is missing on a national scale. In this study, we synthesized 418 pairs of data from 41 experimental studies and investigated the responses of soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) contents to coastal wetlands reclamation in China. The results showed that SOC significantly decreased by 24.77% after reclamation, while TN and TP were significantly increased by 23.57% and 13.55%, respectively. The changes in SOC, TN, and TP after reclamation of coastal wetlands mainly occurred in the 0–40 cm soil layer but not in the deep soil layer. For different land use types, SOC was significantly reduced by 49.48%, 44.57%, and 32.91% after reclaiming wetlands to woodlands, paddy fields, and drylands, respectively. TN and TP were significantly increased by 32.22% and 13.54% after the reclamation of wetlands to drylands, respectively. The reclamation duration also had significant effects on those elements. Specifically, SOC gradually decreased with increasing reclamation duration, while TN and TP increased with the increased reclamation duration. Anthropogenic factors, such as land use types and reclamation duration, rather than climatic factors, dominated changes in SOC, TN, and TP contents after coastal reclamation. Further, our study showed a significant SOC reduction following reclamation, and given the importance of coastal blue carbon, it is essential to reduce wetland reclamation to protect coastal blue carbon. 相似文献
3.
A. Chatterjee R. Lal R.K. Shrestha D.A.N. Ussiri 《Land Degradation u0026amp; Development》2009,20(3):300-307
Minesoils are characterized by low soil organic matter and poor soil physicochemical environment. Mine soil reclamation process has potential to restore soil fertility and sequester carbon (C) over time. Soil organic C (SOC) pool and associated soil properties were determined for reclaimed minesoils under grass and forest landuses of varied establishment year. Three grassland sites of 30, 9, and 1 years after reclamation (G30, G9, and G1) and two forest sites, 11 years after reclamation (RF) and undisturbed stand of 40 years (UF), were selected within four counties (Morgan, Muskingum, Noble, and Coshocton) of southeastern Ohio. Soil bulk density (BD) of reclaimed forest (RF) soil was significantly higher than undisturbed forest (UF) soils within 10–40 cm soil depth profile. Reclamation process increased soil pH from slightly acidic to alkaline and decreased the soil EC in both landuses. Among grassland soils, significant changes in SOC and total soil N contents were observed within 0–10 cm soil depth. SOC contents of G30 (29.7 Mg ha−1) and G9 (29.5 Mg ha−1) were significantly higher than G1 soils (9.11 Mg ha−1). Soil N content was increased from G1 (0.95 Mg ha−1) to G9 (2.00 Mg ha−1) site and then the highest value was found under G30 (3.25 Mg ha−1) site within 0–10 cm soil depth. UF soils had significantly higher SOC and total N content than RF soils at 0–10 and 10–20 cm soil depths. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
4.
为探究不同绿肥品种翻压条件下晋南旱地麦田土壤团聚体稳定性以及有机碳(SOC)和全氮(TN)在不同粒径团聚体的分布特征,深入了解不同种类绿肥的增碳保氮机制。已连续3年(2018—2021年)不同绿肥品种(对照休闲、大豆、绿豆、油葵、玉米)翻压还田后冬小麦收获期0-10,10-20,20-30 cm土壤为研究对象,采用湿筛法进行土壤粒径分级,并分析粗大团聚体(>2 mm)、细大团聚体(0.25~2 mm)、微团聚体(0.053~0.25 mm)和粉黏粒组分(<0.053 mm)中SOC和TN含量,测算团聚体的构成与稳定性(R0.25,>0.25 mm团聚体含量;MWD,平均重量直径;GMD,几何平均直径),并测定各粒径团聚体SOC和TN及其对土壤总有机碳和总氮的贡献率。结果表明:不同绿肥处理下旱地麦田土壤团聚体质量占比均以细大团聚体0.25~2 mm为主(占22.77%~39.71%)。复播绿肥显著增加0-30 cm土层>2 mm粒径团聚体质量占比,以大豆绿肥增加最明显,0.25~2,0.053~0.25 mm粒径团聚体质量占比降低,对<0.053 mm粉黏粒的影响不明显;大豆绿肥对各土层R0.25、MWD和GMD值提高作用明显。大豆和玉米对0-30 cm各土层土壤总有机碳含量具有显著提高作用,分别提高27.83%和25.71%。大豆绿肥进一步提高土壤各粒径团聚体有机碳含量。复播绿肥降低土壤全氮含量,大豆绿肥处理的降低程度最小,且对<0.053 mm粉黏粒全氮含量具有增加作用。0.25~2,>2 mm大团聚体对0-10 cm土层土壤有机碳和全氮的贡献率最高;复播绿肥提升土壤碳氮比(平均21.39),较对照休闲(平均13.71)提高7.68,其中玉米提升效果最佳,大豆次之。综合土壤增碳固氮效果,连续3年翻压大豆绿肥可有效提高旱地麦田土壤团聚体稳定性,提升土壤肥力。 相似文献
5.
土壤添加剂对德国卢萨蒂亚的台矿基质上作物产量和C收支的影响 总被引：1，自引：0，他引：1
A. RODIONOV S. NII-ANNANG O. BENS M. TRIMBORN S. SCHILLEM B. U. SCHNEIDER T. RAAB R. F. H&#;TTL 《土壤圈》2012,22(3):343-350
Opencast lignite mining in the Lusatia region of Germany has resulted in large scale landscape disturbances,which require suitable recultivation techniques in order to promote plant growth and establishment in the remaining nutrient-poor substrates with low water-holding capacity.Thus,the effects of two commercial soil additives (CSA),a hydrophilic polymer mixed with volcanic rock flour and bentonite (a-CSA),and digester solids from biogas plants enriched with humic acids and bentonite (b-CSA),on soil organic carbon (SOC) storage,plant yields and root biomass were assessed after cultivating perennial crops (Dactylis glomerata L.) in monoculture and Helianthus annuus L.-Brassica napus L.in crop rotation systems.The CSA were incorporated into the top 20 cm soil depth using a rotary spader.The results indicated that a-CSA led to a significant increase in plant yield during the first year,and improved root biomass in the following year.As a result,SOC stocks increased,especially in the 0-10 cm soil layer.No significant sequestration of additional SOC was observed on b-CSA-amended plots at the end of both years.Bulk density values decreased in all treatments under the monoculture system.It can be concluded that application of a-CSA enhanced soil water availability for plant uptake and consequently promoted plant growth and organic carbon sequestration.The relative enrichment of organic matter without effects on water-holding capacities of b-CSA treatments suggested that it was not suitable for rapid land reclamation. 相似文献
6.
Soils play a key role in the global carbon cycle, and can be a source or a sink of atmospheric carbon (C). Thus, the effect of land use and management on soil C dynamics needs to be quantified. This study was conducted to assess: (1) the role of aggregation in enhancing soil organic carbon (SOC) and total soil nitrogen (TSN) concentrations for different mulch rates, (2) the association of SOC and TSN with different particle size fractions, and (3) the temporal changes in the SOC concentration within aggregate and particle size fractions with duration of mulching. Two experiments were initiated, one each in 1989 and 1996, on a Crosby silt loam (Aeric Ochraqualf or Stagnic Luvisol) in central Ohio. Mulch treatments were 0, 8, and 16 Mg ha−1 yr−1 without crop cultivation. Soil samples from 0–5 cm and 5–10 cm depths were obtained in November 2000; 4 and 11 years after initiating the experiments. Mulch rate significantly increased SOC and TSN concentrations in the 0–5 cm soil layer only. The variation in the SOC concentration attributed to the mulch rate was 41 per cent after 4 years of mulching and 52 per cent after 11 years of mulching. There were also differences in SOC and TSN concentrations among large aggregate size fractions, up to 2 mm size after 4 years and up to 0ċ5 mm after 11 years of mulching. There were also differences in SOC and TSN concentrations among particle size fractions. Variation in the SOC concentration in relation to particle size was attributed to clay by 45–51 per cent, silt by 34–36 per cent, and to sand fraction by 15–19 per cent. Bulk of the TSN (62–67 per cent) was associated with clay fraction and the rest was equally distributed between silt and sand fractions. The enrichment of SOC and TSN concentrations in the clay fraction increased with depth. The C:N ratio was not affected by the mulch rate, but differed significantly among particle size fractions; being in the order of sand >silt >clay. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
7.
目的土壤肥力显著影响作物产量,了解区域耕地土壤肥力历史变化趋势有助于指导农户施肥,以提升耕地肥力,促进区域农业可持续发展。方法利用陕西省关中地区第二次土壤普查以来40年(1980—2020年)发表的文献、土壤志等相关数据,采用描述性统计方法,分析土壤有机质、全氮、碱解氮、全磷、有效磷、全钾 、速效钾、pH以及容重的变化趋势。结果1980—2020年,以10年为1个阶段,土壤有机质含量在4个阶段的中值依次为11.0、11.1、13.6和18.5 g/kg,整体呈显著上升趋势。土壤全氮含量在最后10年的中值为0.95 g/kg,与前3个10年相比显著提高。土壤碱解氮含量在最后10年的中值 (58 mg/kg) 与第一个10年 (53 mg/kg) 相比有提高。土壤全磷含量4个10年中值依次为0.70、0.76、0.82和1.03 g/kg,整体呈显著增加趋势。土壤有效磷含量在最后10年的中值为21.9 mg/kg,与前3个10年相比显著提高,且最后10年中80%含量数据均超过农学阈值(14 mg/kg)。土壤全钾含量4个10年中值依次为19.3、19.9、18.6和19.6 g/kg,整体变化不明显。土壤速效钾含量在2011—2020年的中值为212 mg/kg,与前3个10年含量(163、149、158 mg/kg)相比显著提高。土壤pH在最后10年的中值 (7.76) 与前3个10年(8.10、7.90、8.00)相比显著下降。而土壤容重4个10年中值依次为1.32、1.31、1.32和1.30 g/cm3,整体变化不明显。结论陕西省关中地区耕地土壤40年来化学肥力中仅全钾含量变化不明显,近10～20年土壤有机质、全氮、全磷、有效磷和速效钾含量均比前20年显著增加,pH显著下降;土壤容重变化不明显。今后关中地区养分管理和耕作制度需要进一步调整,以提升养分利用效率及土壤生产力。 相似文献
8.
绿肥翻压对烟田土壤理化性状及土壤微生物量的影响 总被引：69，自引：3，他引：66
试验于2003年9月至10月河南烟区的襄城县、舞阳县、叶县、罗山县4个试验点种植绿肥,2004年3月进行翻压,以研究绿肥对土壤容重、土壤pH值等理化性质的影响以及对土壤微生物的影响。试验结果表明,绿肥翻压可以有效地降低土壤的容重和土壤的pH值,提高土壤的有机质,同时能促进土壤中微生物数量的大量增加。与空白对照相比,各个处理土壤容重降幅为0.03~0.1 g/cm3,土壤pH值的降幅一般都在0.1~0.6,土壤有机质含量提高0.08%~0.1%。因此利用烟田冬季休闲空间种植和翻压绿肥,可作为提高土壤肥力、改善烟田土壤环境、实现烟叶生产可持续性发展的一个重要措施。 相似文献
9.
试验依托东北农业大学盐碱土长期定位试验站(始建于1995年),研究不同施肥年限下草甸碱土水稳性团聚体含量及其碳、氮分配规律。结果表明,长期施用有机肥可以显著增加0.25 mm水稳性团聚体的含量52.3%~60.8%,0.5~0.25 mm粒级的水稳性团聚体随着种植和有机肥施用年限的提高显著增加。施肥5年后,草甸碱土土壤团聚体中有机碳和全氮含量开始呈现稳中有升的趋势。大团聚体对有机碳和全氮的贡献率分别为47.9%~89.3%和52.9%~82.1%。5 mm和5~2 mm粒级的团聚体中有机碳和全氮含量与该粒级团聚体数量均呈显著性正相关。连续5年高量有机肥的投入,已经对草甸碱土培肥改良起到了显著效果,此后维持正常的施入量即可。 相似文献
10.
以辽东大伙房水库周边防护林典型林分针阔混交林(落叶松-油松-刺槐混交林)、油松林、落叶松林、刺槐林为研究对象,对其土壤养分含量进行测定,研究了不同林分土壤剖面上有机碳、全氮、有机碳储量的分布规律。结果表明:随着土层深度的增大,4种林分的土壤有机碳、全氮含量均逐渐降低;4种林分土壤剖面有机碳含量大小顺序为落叶松林(24.16g/kg)刺槐林(23.07g/kg)针阔混交林(16.06g/kg)油松林(15.76g/kg);全氮含量大小顺序为刺槐林(5.23g/kg)落叶松林(4.57g/kg)油松林(3.45g/kg)针阔混交林(2.42g/kg);C/N平均值大小顺序为落叶松林(7.36)针阔混交林(6.51)油松林(4.67)刺槐林(4.57);4个林分0-40cm土层的有机碳储量大小为落叶松林(112.94t/hm~2)刺槐林(107.40t/hm~2)针阔混交林(105.42t/hm~2)油松林(89.89t/hm~2);4种林分土壤pH无明显差别,各土层土壤pH随土层深度增加而增大;4种林分土壤容重由高到低顺序依次为针阔混交林(1.73g/cm~3)油松(1.65g/cm~3)落叶松(1.64g/cm~3)刺槐(1.56g/cm~3)。4个林分土壤有机碳含量与土壤全氮含量互相间均存在极显著正相关关系,土壤有机碳、全氮含量与C/N之间则没有明显相关关系;在针阔混交林中,土壤容重、土壤全氮含量和土壤pH与土壤有机碳之间存在线性数量关系,而其他纯林则没有这种关系。 相似文献
11.
向土壤中添加生物质炭已被认为是改善土壤质量,增加碳吸存的有效措施。通过模拟实验,利用同位素δ13C标记技术,研究稻草及其制备的生物质炭添加对土壤团聚体有机碳的影响。结果表明：稻草和生物质炭对土壤团聚体中新形成碳和原有机碳的影响截然不同。培养112 d,来自稻草或生物质炭的新碳主要进入到中团聚体（50 ~ 250 μm）中,比例为70.3% ~ 75.3%。与对照土壤相比,稻草添加显著促进了大团聚体（250 ~ 2 000 μm）原有机碳的分解（p <0.05）,但对中团聚体和微团聚体（<50 μm）原有机碳的影响并不明显,而生物质炭添加（SB250和SB350）则对大团聚体和中团聚体原有机碳没有显著影响,但SB250处理（土壤中加入250℃热解制备的生物质炭）显著抑制了微团聚体原有机碳的分解（p <0.05）,而SB350处理（土壤中加入350℃热解制备的生物质炭）的则无影响。对于同一粒级团聚体,稻草与生物质炭处理的区别,主要体现在新碳分配上,而对原有机碳的影响并不显著。 相似文献
12.
《Land Degradation u0026amp; Development》2017,28(3):1038-1046
Within the Mediterranean basin, soil tillage enhances the mineralisation of soil organic matter. We assessed the short‐term impact of shallow tillage [field cultivator (FC), rotary tiller (RT) and spading machine (SM)] on some soil quality indicators [bulk density, water‐stable aggregates, total and labile organic C pools (microbial biomass and extractable organic C), soil respiration and related eco‐physiological indexes] in a Sicilian vineyard. Also no tillage was included. We hypothesized that (i) RT and FC worsened soil quality indicators more than SM, and (ii) within the same tillage system, labile C pools, soil respiration and eco‐physiological indexes will respond more efficiently than chemical and physical soil properties since the tillage starts. The experiment started at March 2009, and each tillage type was applied three times per year (March or April, May and June), with soil tilled up to 15‐cm depth. Soil was sampled (0–15 and 15–30‐cm depth) in March 2009, April 2010, May 2012 and June 2014. SM was very effective in preserving soil organic matter pool and in improving any monitored soil quality indicator, similarly to no tillage. By contrast, RT was the most deleterious machine as it worsened most investigated indicators. Such deleterious effects were due to drastic disruption of soil aggregates and consequent exposition of protected soil organic matter to further microbial mineralization. Labile organic C pools and microbial quotients were the most responsive soil parameters for assessing the impact of shallow tillage on soil quality, even in the short term (<5 years). Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
13.
Injection of slurry or digestate below maize seeds is a relatively new technique developed to improve nitrogen use efficiency. However, this practice has the major drawback of increasing nitrous oxide (N2O) emissions. The application of a nitrification inhibitor (NI) is an effective method to reduce these emissions. To evaluate the effect of the NI 3,4‐dimethypyrazole phosphate (DMPP) on N2O emissions and the stabilization of ammonium, a two‐factorial soil‐column experiment was conducted. PVC pipes (20 cm diameter and 30 cm length) were used as incubation vessels for the soil‐columns. The trial consisted of four treatments in a randomized block design with four replications: slurry injection, slurry injection + DMPP, digestate injection, and digestate injection + DMPP. During the 47‐day incubation period, N2O fluxes were measured twice a week and cumulated by linear interpolation of the gas‐fluxes of consecutive measurement dates. After completion of the gas flux measurement, concentration of ammonium and nitrate within the soil‐columns was determined. DMPP delayed the conversion of ammonium within the manure injection zone significantly. This effect was considerably more pronounced in treatment digestate + NI than in treatment slurry + NI. Regarding the cumulated N2O emissions, no difference between slurry and digestate treatments was determined. DMPP reduced the release of N2O significantly. Transferring the results into practice, the use of DMPP is a promising way to reduce greenhouse gas emissions and nitrate leaching, following the injection of slurry or digestate. 相似文献
14.
Lawrence Aula Natasha Macnack Peter Omara Jeremiah Mullock 《Communications in Soil Science and Plant Analysis》2016,47(7):863-874
Carbon sequestration via sound agronomic practices can assist in combating global warming. Three long-term experiments (Experiment 502, Experiment 222, and The Magruder Plots) were used to evaluate the effect of fertilizer nitrogen (N) application on soil organic carbon (SOC), total nitrogen (TN), and pH in continuous winter wheat. Soil samples (0–15 cm) were obtained after harvest in 2014, analyzed, and compared to soil test results from these experiments in 1993. Soil pH decreased with increasing N fertilization, and more so at high rates. Nitrogen application significantly increased TN in Experiment 502 from 1993 to 2014, and TN tended to be high at high N rates. Fertilizer N significantly increased SOC, especially when N rates exceeded 90 kg ha?1. The highest SOC (13.1 g kg?1) occurred when 134 kg N ha?1 was applied annually. Long-term N application at high rates increased TN and SOC in the surface soil. 相似文献
15.
《Land Degradation u0026amp; Development》2018,29(6):1565-1573
Bauxite mining requires the removal of the vegetation and topsoil, thus causing considerable impacts on both natural and managed ecosystems. This is typically the case of agricultural activities across Minas Gerais, South‐eastern Brazil, where bauxite mining often displaces pastures and coffee plantations. In this study, our objective was to assess the effects of chemical and organic fertilizations combined with cover crops on the re‐establishment of coffee plantations following bauxite mining. The experiment consisted of a split‐plot design which main plot received 4 types of fertilization: no fertilization, chemical fertilization (CF), poultry litter (PL), and CF + PL. In subplots, 4 cover crops were cultivated in between the rows of the coffee plantation, including: no cover crops, grass (Brachiaria brizantha [B]), legume (Stylosanthes spp. [S]), and B + S. We had 4 blocks as replicates. Organic and chemical fertilization (PL + CF) combined with cover crops (B + S) led to significant recovery of soil organic carbon (SOC), soil organic nitrogen (SON), and KMnO4‐oxidizable SOC. PL + CF and B + S also led to SOC increments of 14.5 g kg−1 soil (0–10‐cm depth). Based on isotopic data (13C), both cover crops, isolated or combined, contributed to the recovery of SOC. Over 3 consecutive harvests, coffee bean yield was consistently above 1,800 kg ha−1 under PL or PL + CF, except when B was the only cover crop. Managing fertilization and cover crops can determine the recovery of SOC, SON and the capacity of soil to sustain the re‐establishment of coffee plantations following bauxite mining. 相似文献
16.
采煤塌陷区复垦土壤团聚体碳氮分布对施肥的响应 总被引：4，自引：2，他引：4
为了揭示长期不同培肥措施下采煤塌陷区复垦土壤团聚体有机碳氮含量的变化规律,通过干筛法研究了不施肥(CK)、单施有机肥(M)、单施化肥(CF)、有机肥与化肥配施(MCF)、生物有机肥与化肥配施(MCFB)5种培肥措施下复垦4年和8年土壤各粒级团聚体分布组成特征以及各团聚体有机碳氮含量的变化规律。结果表明,复垦土壤团聚体含量随粒级减小呈先减小后增大的变化趋势,其中以3~2mm粒级团聚体含量最低,占团聚体总量2%~3%,以2~1mm粒级团聚体含量最高,占团聚体总量25%~31%。不同培肥措施下复垦4年和8年土壤团聚体分布特征无明显差异,但较未复垦生土明显降低了7mm和7~5mm团聚体含量。复垦8年土壤的平均重量直径(MWD)、几何平均直径(GMD)高于复垦4年土壤,分形维数(D)值低于复垦4年土壤。各培肥处理间以单施有机肥MWD、GMD值最高,D值最低。各培肥处理土壤团聚体有机碳氮含量随粒径减小递增,以0.5~0.25mm粒径团聚体最高,而有机碳储量以2~1mm粒级团聚体最高,分别占24.2%~33.8%和17.0%~33.1%。各处理间有机碳氮含量以单施有机肥处理最高,但不同处理间有机碳氮储量无显著差异。总体表明,采煤塌陷区复垦4年和8年土壤团聚体分布特征及碳氮储量无明显变化,单施有机肥可提高复垦土壤团聚体有机碳氮含量及团聚体稳定性。 相似文献
17.
以贵州关岭花江喀斯特峡谷花椒(HJ)、火龙果(HL)、花椒火龙果混交(HHL)、皇竹草(HZ)、苜蓿(MX)、圆柏(YB)、圆柏女贞混交(YBN)、撂荒地(LH)、坡耕地(PD)9种典型石漠化治理措施为研究对象,研究不同治理措施土壤剖面有机碳、全氮含量和储量、水溶性有机碳含量分布规律。结果表明:各治理措施0-20 cm土层土壤有机碳、全氮含量及储量、水溶性有机碳含量均随土壤剖面深度增加而降低,具有明显的表聚现象。其中土壤有机碳、全氮含量0-20 cm土层平均值大小顺序分别为YB>YBN>LH>HJ>MX>PD>HHL>HL>HZ、YBN>YB>LH>PD>MX>HJ>HZ>HHL>HL,土壤有机碳、全氮储量及水溶性有机碳含量也均表现为YB、YBN、LH显著大于其他6种治理措施;各治理措施土壤C/N为7.19~16.35。相关性分析表明,土壤有机碳含量与土壤全氮含量、有机碳储量、水溶性有机碳含量存在极显著相关,土壤容重是土壤碳氮指标的关键因子,具有较好相关性。研究阐明,在今后石漠化治理过程中,退耕还林、撂荒地有利于喀斯特生态环境治理与保护,花椒林可作为喀斯特山区农业生产或生态恢复过程中优先考虑的经济植被类型。 相似文献
18.
Hongfei Liu Chutao Liang Zemin Ai Jiaoyang Zhang Yang Wu Hongwei Xu Sha Xue Guobin Liu 《Land Degradation u0026amp; Development》2019,30(14):1677-1690
The interaction between plants and arbuscular mycorrhizal fungi in the rhizosphere plays a vital role in driving vegetation recovery and restoration of soil nutrients. However, how this interaction affects vegetation succession and how soil nutrient recovery is driven by vegetation restoration and rhizosphere processes are still largely unknown. In this study, a well‐documented grassland restoration chronosequence on the Loess Plateau, China (fields at 0, 7, 12, 17, 22, and 32 years after farmland abandonment and a natural grassland reference) was selected. The species richness and diversity reached maximum values between 17 and 22 years after farmland abandonment, whereas the plant total above and belowground biomasses simultaneously peaked at 22 years and then remained stable. In the dominant plant rhizosphere and bulk soil concentrations of total glomalin‐related soil protein (including both old and recently produced fungal proteins) substantially increased from 3.58 to 4.87 g kg−1 and from 2.67 to 3.86 g kg−1, respectively, between 12 and 32 years after farmland abandonment. The concentrations of soil organic carbon (SOC) and total nitrogen (TN) in the plant rhizosphere and bulk soil significantly increased between 17 and 32 years and reached the levels of the natural grassland. The aboveground plant biomass, soil SOC, and TN concentrations were positively correlated with the glomalin‐related soil protein (GRSP) concentration (p < .05). Our study suggested that interactions among plant‐mycorrhizae association, plant diversity, and biomass promote GRSP and nutrient accumulation in the plant rhizosphere and bulk soil, and GRSP largely contributes to SOC stabilization and the accumulation of SOC and TN. 相似文献
19.
[目的] 分析施加生物炭配合深松对农田耕层土壤容重、土壤结构稳定性及有机碳的影响,为土壤结构改良提供科学合理的调控措施和理论依据。[方法] 基于冬小麦—夏玉米轮作体系,2017—2019年大田试验期间,在小麦季设置生物炭施用量分别为0,3 000,6 000 kg/hm2(B0,B1和B2)的3个处理,在玉米季设置传统贴茬播种(P)和深松耕作播种(S)2个耕作处理,共计B0P,B1P,B2P,B0S,B1S,B2S 6个处理。[结果] ①两个轮作后,相同耕作方式下,土壤容重随生物炭用量的增加而降低,其中B2S较B0S显著降低(13.59%);同一施炭水平下,各处理土壤容重呈现出深松＜传统的特征,深松容重整体较传统低4.95%。②连续施加生物炭配合深松耕作两年后,B2S处理下的有机碳含量达到最高,比B0P显著增加(42.15%),比B2P增加1.03%。③两个轮作后,随生物炭用量的增加机械性团聚体含量(DR0.25)、水稳性团聚体含量(WR0.25)、平均重量直径(MWD)呈上升趋势,相反土壤团聚体破坏率(PAD)及土壤不稳定团粒指数(ELT)呈逐渐下降趋势,且表现为B2S处理均优于其他各处理的特征,表明高添加量生物炭配合深松耕作较传统耕作能更有效地提高团聚体稳定性。[结论] 小麦季基施6 000 kg/hm2生物炭并配合玉米季深松有利于提高土壤团聚体稳定性,改善华北平原农田土壤结构。 相似文献
20.
Xiao Pu Yushu Shan Siyang Chen Zhaoliang Ding Fanghua Hao 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(8):749-764
Abstract Limited information is available for understanding factors controlled dynamics of soil organic carbon (SOC) and total nitrogen (TN) affected by long-term conventional cultivation in seasonally frozen soils. A 19-year observation in this study was conducted in north-eastern China to evaluate effects and relative importance of potential factors. SOC variation extent was greater relative to global average as per unit of annual mean air temperature and precipitation changed. Increased carbon sequestration was observed in meadow lessive, while slight to moderate declines occurred in meadow-boggy soil and meadow soil. However, no differences in TN were found across soil types. At sites with low slope, carbon and nitrogen sequestration increased, largely due to water movement. Increased biomass with introducing 1-year oilseed rape/fallow in crop rotations could promote SOC and TN accumulation in the long run. Planting proportion of crops could also regulate carbon and nitrogen levels at a farm scale; the optimal ratio was observed in the range of 0.8–1.4. High crop yield was associated with lower carbon and nitrogen levels, and nutrient thresholds of yielding increment were observed as 25.7 g kg?1 for carbon and 2.6 g kg?1 for nitrogen. The length of frost-free period or cultivation period could not help sequestrating carbon and nitrogen. Chemical fertilizer with crop residues provoked SOC and TN increments compared with no chemical fertilizer plus little organic manure. Different factors exerted different tendentious influences, leading to subtle differences in SOC and TN variation rates. Accordingly, optimal cultivation strategies could be developed to reduce nutrient losses and mitigate greenhouse gas emissions. 相似文献