Modifications of the phosphorus cycle with development of lignite mine soils

Various aspects of the P cycle in four and seven year old soils from the Meirama lignite mine (northwest Spain) were studied. With increasing soil age, The organic P (P_o) content increased in parallel with the organic matter content. the observed increase in secondary inorganic P (Bic—P_i + NaOH-P_i + us-NaOH P_i) is related to the increase in the retention capacity for P with soil age. the observed increase in the HCl-P fraction can be attributed to a gradual dissolution of the non-extractable forms of P produced from fertilizers added in the course of spoil management. Both the C:P_o ratio and phosphatase activity also increased with soil age, suggesting that biochemical mineralization processes are taking place and indicating a need for the hydrolysis of phosphate esters to ensure an adequate phosphorus supply to plants. All these findings suggest that in the long term plants May, suffer a pronounced P deficiency.     

Development of pollution-neutralizing properties in very young mine soils

Various properties capable of neutralizing environmental pollution (aggregate stability, buffer capacity and ion adsorption capacity) were determined in spoil from a lignite mine in Galicia (northwest Spain) and in mine soils of four and seven years age developed from this spoil. Buffer capacity and the adsorption of copper, cadmium and phosphate increased markedly with soil age, whereas the dispersion ratios of both macro- and micro-aggregates decreased sharply. These changes are attributed to the known increase in organic matter and extractable iron and aluminium. These components aid interparticle binding and create both exchange sites and specific adsorption sites. The ultimate causes are thought to be the successful establishment of an active field plant cover, the considerable colloid content of the parent material, the management of the mine soils and the climatic conditions of the area, which favour both the accumulation of soil organic matter and the weathering of the parent material.     

Short Communication Actual cation exchange capacity in lignite containing pyritic mine soils

The actual cation exchange capacity (CEC_act) in sandy mine soils from Tertiary sediments increases with the lignite contents of the substrates. Therefore, lignite is important for nutrient storage and availability in these soils. Base saturation varies over a wide range of 4 — 100% according to soil pH. For the determination of CEC_act, the high contents of soluble salts typical for these substrates have to be considered for reliable results.     

黄土区露天煤矿排土场重构土壤颗粒组成的多重分形特征

排土场复垦土壤是由人为方式通过不同重构工艺构成的复杂整体,其由不同颗粒组成、具有不规则形状的特性,其核心工作是重构一个适合植被生长的土壤结构。为了更好地对排土场重构土壤结构进行定量表征,该文通过引入土壤多重分形理论,对山西平朔矿区安太堡露天煤矿排土场4种重构土壤方案(含砾石黄土母质覆盖、含煤矸石黄土覆盖、全黄土母质覆盖、含料姜土黄土覆盖)的2 mm以下土壤粒径分布进行了多重分形参数计算,计算参数包括广义维数谱D(q)、多重分形奇异性指数α(q)以及多重分形谱函数f(α(q))等,并对不同分形参数之间的关系进行了计算。通过研究发现:该研究区大型露天煤矿排土场重构土壤颗粒组成具有明显的多重分形特征,D(0)、D(1)、D(1)/D(0)、Δα和Δf反映了土壤颗粒分布的非均匀质特征;该研究区黄土重构剖面的土壤粒径分布范围较小、测度集中程度较高、离散程度较小,土壤粒径组成非均匀性低;多重分形参数之间具有较好的相关性,可以简化选择D(0)、D(1)/D(0)和Δα或D(0)、D(1)和Δf 3个参数实现对黄土区重构土壤颗粒组成分布的定量表征;黄土重构剖面0～90 cm内土壤多重分形参数变化明显,黄土区表层土壤覆盖厚度应在90 cm以上,煤矸石和砾石对重构土壤颗粒的离散程度有一定的影响,应排弃在90 cm以下土层。该研究可为黄土区露天煤矿排土场土地复垦以及重构土壤质量的量化提供理论依据。     

Microbial use of lignite compared to recent plant litter as substrates in reclaimed coal mine soils

In the Lusatian mining district, rehabilitated mine soils contain substantial amounts of lignite in addition to recent carbon derived from plant litter. The aim of this study was to examine the importance of the two organic matter types as substrates for soil microbial biomass in mine soils containing organic matter with a contrasting degree of humification. Samples were taken from the lignite-containing overburden material, from a mine soil under 14-year-old black pine (Pinus nigra) and from a mine soil under 37-year-old red oak (Quercus rubra). Overburden material was ameliorated with alkaline ash and incubated in an identical manner as the 14-year-old and 37-year-old mine soils for 16 months. Carbon mineralisation was monitored throughout. After 0, 3, 6, 12 and 16 months, samples were removed and analysed for chemical parameters and for microbial biomass. In addition, ¹⁴C activity measurements in bulk soil and microbial biomass were used to estimate their lignite content.Despite the high content of organic carbon in lignite-rich overburden material, low contents of microbial biomass were recorded. Ash-amelioration led to high pH values in the overburden material, resulting in high concentrations of dissolved organic carbon most likely derived from lignite. Development of the microbial community was subsequently stimulated by presence of an easily available carbon source. In older mine soils, larger amounts of microbial biomass are most likely related to the presence of recent organic matter. Radiocarbon analysis of the microbial biomass extracted from the 14-year-old mine soil indicated higher lignite carbon contribution than recorded for microbial biomass of the 37-year-old mine soil. The highest concentration of lignite C present in microbial biomass as indicated by the C_mic/C_org ratio was, however, observed in the ameliorated overburden material. Therefore, we conclude that the importance of lignite as a carbon source for micro-organisms decreases when recent organic matter is present in the older stages of mine soil development.     

黄土丘陵区露天煤矿复垦土壤熟化过程中团聚体碳氮演变特征

矿区土地复垦中,由于机械碾压导致复垦土壤呈现高压实状态,复垦土壤的有机质则因机械扰动而矿化。探究复垦土壤团聚体与有机质恢复机理,可为深入理解露天煤矿高压实复垦土壤质量演替规律提供依据。以平朔露天煤矿典型植被恢复模式--刺槐纯林不同复垦年限（0、3、12、14、17、25、28、32 a）土壤及周边未扰动土壤（CK）为研究对象,采集0～20 cm表层土壤样品,分析土壤水稳性团聚体（>2 000 μm、>250～2 000 μm、53～250 μm、<53 μm）及团聚体碳（C）、氮（N）以及13C和15N同位素特征。结果表明：1）土地复垦中机械碾压破坏了土壤水稳性团聚体结构与稳定性,但随着复垦时间增加,32 a样地>250～2 000 μm团聚体的比例较0 a提高737.02%,而53～250 μm团聚体比例则降低19.25%;团聚体稳定性随着复垦时间而增加,表现为32 a样地土壤团聚体平均重量直径（Mean Weight Diameter,MWD）较0 a提高133%。2）各粒径团聚体C、N及C/N均随着复垦时间增加而增加,>2 000和>250～2 000 μm团聚体C和N在土壤总C和N中占主导地位。>2 000和>250～2 000 μm团聚体C/N整体上高于53～250 μm团聚体。3）各样地土壤δ13C变化范围为?15.14‰～?26.40‰;δ15N的变化范围为1.13‰～10.87‰。>2 000、>250～2 000和<53 μm团聚体的δ13C值及>2 000 μm团聚体的δ15N值随复垦年限增加呈现降低趋势。与>2000 μm和>250～2 000 μm团聚体相比,53～250和<53 μm团聚体中13C显著富集（P<0.05）,这表明复垦土壤熟化过程中,土壤C从大粒径团聚体向小粒径周转。4）>2 000与>250～2 000 μm团聚体中,新C占土壤总C的比例为>80%,且各样地间差异不显著（P>0.05）,而在<53 μm团聚体中,新C的比例在复垦14～17 a间显著增加,此后则变化不显著。上述结果表明,土地复垦中机械碾压增加了小粒径团聚体的比例,降低了团聚体稳定性,而随着复垦时间增加,植被恢复促进了土壤团聚体结构、稳定性及C、N的恢复。     

基于CT分析露天煤矿复垦年限对土壤有效孔隙数量和孔隙度的影响

露天煤矿排土场由于排土过程中大型机械压实等作用会对土壤的孔隙结构产生影响,重构适合于植被生长的土壤孔隙结构是排土场土地复垦的重要工作。为对排土场重构土壤孔隙结构进行定量分析,该文采用高精度无损计算机断层扫描技术（CT）对山西平朔矿区安太堡露天煤矿排土场平台全黄土母质覆盖的不同复垦年限（0、20、23 a）以及原地貌的土壤进行分层扫描成像,并利用Photoshop和Arcgis软件对扫描图像进行处理和统计分析,探讨了排土和复垦对土壤孔隙数量和孔隙度的影响,分析了排土场重构土壤大、中和小孔隙的变化。结果表明：原地貌土壤孔隙数量和孔隙度最大,其次是复垦23和20 a的土壤,排土后未复垦土壤孔隙数量和孔隙度最小。采矿和排土等活动由于大型机械压实作用降低了土壤孔隙数量和孔隙度,尤其是大孔隙数量和大孔隙度;土地复垦对增加土壤孔隙数量和孔隙度有一定的作用,但是过程比较缓慢。采矿和排土等活动对表层土壤孔隙数量和孔隙度的影响要高于底层土壤。该研究可为黄土区大型露天煤矿排土场重构土壤结构的优化与土地复垦措施选择提供依据。     

不同种植模式下菜地土壤腐殖质组分特性的动态变化

通过在南京普朗克有机农场开展的9年长期定位监测,研究了有机(露地和大棚)和常规种植模式下蔬菜地耕层土壤有机碳和土壤腐殖质组分特性的动态变化。结果表明,有机露地、有机大棚和常规露地种植土壤有机碳含量分别从11.41、9.29、9.00 g k g-1提高至15.35、20.90、10.00 g kg-1;胡敏酸碳(CHA)分别从1.79、1.23、1.14 g kg-1提高至2.11、3.11、1.31 g kg-1;富里酸碳(CFA)分别从2.19、1.88、1.73 g kg-1提高至2.44、2.68、1.91 g kg-1。两种有机种植模式的土壤有机碳及腐殖质组分含量增加达到显著水平,而常规种植模式下的变化不显著。两种有机种植模式下表征土壤腐殖质品质的胡/富比(CHA/CFA)、胡敏酸占总腐殖物质的比例(PQ值)均高于常规种植模式,土壤富里酸的E4/E6值、色调系数(ΔlogK)值随着种植时间增加的幅度较常规种植模式更大,土壤胡敏酸芳化度呈现先降低后增高的趋势,但在常规种植下变化不明显。说明土壤在长期有机种植模式下不仅更有利于土壤有机碳的积累,而且能促进土壤腐殖化进程。     

Humus forms in terrestrial ecosystems: a framework to biodiversity

Humus forms are the seat of most biological transformations taking place in terrestrial ecosystems, being at the interface between plants, animals and microbes. The diversity of terrestrial humus forms (mor, moder and mull) can be attributed to the existence of different patterns (strategies) for the capture and use of resources by ecosystems, in ascending order of biodiversity and bioavailability. Arguments are found in the parallel development of humus forms and terrestrial ecosystems, in exclusion mechanisms between organisms living in different humus forms, and in palaeontological studies. The diversification of terrestrial life forms in the course of Earth history, concomitant with an improvement in resource availability due to the development of sedimentary layers at the surface of continents, may explain the successive appearance of more active humus forms enabling the co-existence of an increasing number of organisms. Contradictory reports about the relationships between biodiversity and stability of ecosystems can be explained by the existence of different belowground pathways making ecosystems more stable.     

Amino acids in grassland soils: Climatic effects on concentrations and chirality

The response of soil organic nitrogen (SON) dynamics to climate may partly be deduced from changes in the concentration and origin of the major N constituents in soil, such as amino acids. In this study, we determined the enantiomers of bound amino acids in 18 native grassland soils (0–10 cm) that were sampled along a transect from central Saskatchewan, Canada, to Southern Texas, USA. Mean annual temperature (MAT) ranged from 0.9 to 23.4 °C and mean annual precipitation (MAP) from 300 to 1308 mm. d-alanine and d-glutamic acid served as markers for the bacterial origin of SON. The d-content of lysine, phenylalanine, and aspartic acid indicated an ageing of the respective SON forms. Deuterium labeling was applied to account for hydrolysis-induced racemization reactions. We found that the concentration of the bacterial biomarkers was weakly but significantly parabolically related to MAT, as previously reported for microbial-derived amino sugars. The age markers d-lysine, d-phenylalanine, and d-aspartic acid comprised 2–15% of the respective l-form. The presence of these compounds demonstrated that the structures that contained these d-enantiomers had survived microbial attack, i.e., these hydrolyzable SON forms were conserved in soil despite a living environment. First estimates indicate that the mean residence time of the lysine-containing organic matter forms extend beyond a century. Within this time-scale we did not find that climate significantly affects the degree of ageing of SON constituents in the studied topsoils.     

施肥对酸性菜园土壤莴笋硝酸盐和叶片养分形态的效应

通过田间试验研究了3种酸性菜园土壤(强酸性、酸性和微酸性土壤)不同氮磷钾配比及其与硝酸盐复合控制剂配施对莴笋产量、硝酸盐及叶片养分形态的影响。结果表明,莴笋产量以微酸性土>酸性土>强酸性土,酸性和强酸性土壤上配施硝酸盐复合控制剂可使莴笋显著增产(达6.2％～18.2％),而微酸性土壤则相反。HNK配施硝酸盐复合控制剂在3种土壤上分别降低莴笋茎和叶硝酸盐含量25.1％～76.3％和3.1％～27.7％(微酸性土除外),降低作用以茎>叶,以HNK+C2处理效果最好。莴笋叶片硝酸盐含量以酸性土壤>微酸性土壤>强酸性土壤,茎中硝酸盐以酸性土壤为最高。莴笋叶片氮、磷、钾形态分别以蛋白氮、非蛋白磷、非蛋白钾为主,HNK配施硝酸盐复合控制剂(HNK+C3除外)提高莴笋叶片蛋白氮占全氮、蛋白磷占全磷和蛋白钾占全钾的比例。莴笋叶片硝酸盐含量与全氮、蛋白氮、全磷、蛋白磷和蛋白钾含量呈极显著负相关。     

Evaluation of three organic wastes for reclaiming burnt soils: Improvement in the recovery of vegetation cover and soil fertility in pot experiments

The efficacy of three abundant organic wastes: poultry manure (PM), cattle slurry (CS) and sewage sludge (SS) for the reclamation of burnt soils was evaluated. A forest soil, previously furnace-heated in order to simulate exposure to a high-intensity wildfire, was labelled with nitrogen-15 (¹⁵N) to evaluate the contribution of N derived from the organic waste to the burnt soil and vegetation. Four treatments were performed with the heated ¹⁵N-labelled soil: an unamended control soil (S) and three waste amended soils (S+PM, S+CS and S+SS) at a dose waste of 167mg total N kg^–1 soil. Lolium perenne was grown in all the pots for 3 months. In each treatment the phytomass produced and its N content decreased significantly in the following order of treatments: S+PM S+CS > S+SS S. The percentage of plant N derived from the waste was similar in the S+PM (22.8%) and S+CS (24.0%) treatments, but significantly lower in the S+SS treatment (16.5%). At the end of the 3 month experimental period, the available N reserves (phytomass N+soil inorganic N) in the control soil accounted for 51.5–71.5% of those in the S+PM, S+CS and S+SS treatments, whereas the yield of the plants was only 13.4–29.8% of that in the manured soils. These results demonstrated the importance of the addition of organic wastes, particularly PM, for the recovery of the vegetation cover and for the stabilization of the soil ash layer. They also showed that the level of N was not the main controlling factor of plant growth in the control soil, which, moreover, did not show evidence of a shortage of macronutrients, i.e. phosphorus, potassium, calcium or magnesium. It is hypothesized that, as occurs in heat-sterilized soils, phytomass production in the control-heated soil could have been inhibited by the heat-induced production of phytotoxic compounds, their negative effects being microbially or chemically suppressed by the addition of organic wastes. Received: 3 March 1997     

Bacillus asahii comes to the fore in organic manure fertilized alkaline soils

Organic manure (OM) fertilization has a profound impact on agroecosystems. However, little is known about temporal responses and roles of the specific soil microbial guilds involved in the increases of soil fertility and crop yield triggered by OM fertilization. To unravel these interactions, a series of fresh and archived soil samples from a fertilization experiment started in 1989 in North China Plain (NCP) was systematically investigated. Molecular assays of contemporary fresh samples unravel that Bacillus asahii responded most distinctly to OM fertilization, while no shifts in microbial community structure were observed between chemical fertilizations and the control without fertilization; a series of archived soil samples from 1989 to 2009 reveal that the indigenous B. asahii took 2–4 years to become specifically dominant and its ratio fluctuated between 40% and 72% during 20 years. Culture-dependent assessments of isolated B. asahii strain further indicate that its rise subsequently played a key role in the increases of both crop yield and soil fertility, especially via accelerating carbon and phosphorus cycling. This insight deepens our understanding of how OM impacts agroecosystems through soil microbial processes, and highlights the possibility of using archived microbial information as a reference to develop an efficient and sustainable agricultural strategy.     

植被毯覆盖对旱区露天煤矿土壤生态化学计量及酶活性的影响

为阐明不同材质植被毯覆盖对干旱地区露天煤矿土壤养分及酶活性的影响,以宁夏贺兰山自然保护区大峰矿为研究对象,分析秸秆、椰丝及秸秆-椰丝3种不同材质植被毯覆盖后矿区土壤有机碳、全氮、全磷、脲酶、蛋白酶、碱性磷酸酶和过氧化氢酶及生态化学计量比特征。结果表明：1）植被毯覆盖增加土壤表层有机碳和总氮含量且最大值为椰丝植被毯覆盖土壤,总磷含量无明显变化,10～20 cm土壤有机碳、总氮、总磷含量无明显变化;2）植被毯覆盖增加C/P、N/P且最大值同样为椰丝植被毯覆盖土壤,C/N无明显变化;3）植被毯覆盖土壤脲酶和碱性磷酸酶活性显著高于裸地,且0～10 cm大于10～20 cm,蛋白酶活性无显著变化,过氧化氢酶活性仅有椰丝植被毯的0～10 cm显著高于10～20 cm;4）土壤酶活性与环境因子的相关性和冗余分析结果显示：土壤TP、C/N是制约酶活性的主要影响因子,而N/P、TN是驱动酶活性的主要因子。三种植被毯覆盖后,土壤表层养分含量增加,同时增加了土壤表层的C/P和N/P,且促进表层土壤酶活性。此外,4种酶活性之间也存在显著正相关关系（P<0.01）。相对于秸秆、秸秆-椰丝植被毯,椰丝植被毯...     

Nitrogen mineralization in relation to site history and soil properties for a range of Australian forest soils

Rates of N mineralization were measured in 27 forest soils encompassing a wide range of forest types and management treatments in south-east Australia. Undisturbed soil columns were incubated at 20°C for 68 days at near field-capacity water content, and N mineralization was measured in 5-cm depth increments to 30 cm. The soils represented three primary profile forms: gradational, uniform and duplex. They were sampled beneath mature native Eucalyptus sp. forest and from plantations of Pinus radiata of varying age (<1 to 37 years). Several sites had been fertilized, irrigated, or intercropped with lupins. The soils ranged greatly in total soil N concentrations, C:N ratios, total P, and sand, silt, and clay contents. Net N mineralization for individual soil profiles (0–30 cm depth) varied from 2.0 to 66.6 kg ha^-1 over 68 days, with soils from individual depths mineralizing from <0 (immobilization) to 19.3 kg ha^-1 per 5 cm soil depth. Only 0.1–3.1% of the total N present at 0–30 cm in depth was mineralized during the incubation, and both the amount and the percentage of total N mineralized decreased with increasing soil depth. N fertilization, addition of slash residues, or intercropping with lupins in the years prior to sampling increased N mineralization. Several years of irrigation of a sandy soil reduced levels of total N and C, and lowered rates of N mineralization. Considuring all soil depths, the simple linear correlations between soil parameters (C, N, P, C:N, C:P, N:P, coarse sand, fine sand, silt, clay) and N mineralization rates were generally low (r<0.53), but these improved for total N (r=0.82) and organic C (r=0.79) when the soils were grouped into primary profile forms. Prediction of field N-mineralization rates was complicated by the poor correlations between soil properties and N mineralization, and temporal changes in the pools of labile organic-N substrates in the field.     

Near‐infrared spectroscopy for rapid estimation of microbial properties in reclaimed mine soils

Several chemical and microbial properties of mine soils need to be measured for comprehensive assessment of the reclamation success. The objective of this study was to evaluate the ability of NIR spectroscopy to predict organic C (C_org), total N (N_t), and several microbial properties of mine soils reclaimed for forestry. Soils samples (n = 154) were collected at two reclaimed areas in central and S Poland, and their spectra in the NIR region (including the visible range, 400–2500 nm) were recorded. A half of the samples was used to develop calibration equations, and another half was used for validation. The modified partial least squares regression was applied to build calibration equations using the whole spectrum (0 to 2nd derivative). The best predictions were obtained for C_org and N_t (ratio of standard deviation to standard error of prediction in the validation stage [RPD] = 3.4 and 4.1; the regressions coefficients [a] of linear regression [measured against predicted values] = 0.94 and 0.96; correlation coefficients [r] = 0.96 and 0.97, respectively). Very well predictive models applicable for quantitative measurements were obtained also for microbial biomass, basal respiration, and the activities of dehydrogenase and acid phosphatase (RPD = 2.3–2.5, a = 0.90–0.99, r = 0.90–0.92). Prediction of urease activity was slightly worse (RPD = 2.1, a = 0.88, r = 0.87) but sufficient for rough estimation. The obtained results indicated the ability of NIR spectroscopy to predict complex soil microbial properties. Therefore, application of this analytical method may improve the assessment of recovery of microbial functions in reclaimed post‐mining barrens.     

Differential tolerances of oat cultivars to aluminum in nutrient solutions and in acid soils of Poland

Aluminum tolerant oat cultivars are needed for use on acid soil sites where neutralization of soil acidity by liming is not economically feasible. Oat germplasm in Poland has not been examined for range of Al tolerance. Eleven Polish oat cultivars were screened for Al tolerance in nutrient solutions containing 0, 5 and 15 mg L^‐1 Al. Three of these cultivars showing high to moderate tolerance to Al in nutrient solutions were also grown in greenhouse pots of soil and in field plots of soil over a pH range of 3.8 to 5.5 as determined in 1 N KC1.

The eleven oat cultivars differed significantly in tolerance to Al in nutrient solutions. Based on relative root yield (15 mg L^‐1 Al/no A1%), the cultivars ‘Solidor’ and ‘Diadem’ were most tolerant and ‘Pegaz’ and ‘B‐20’ were least tolerant. For these three cultivars, the order of tolerance to acid soil agreed with the order of tolerance to Al in nutrient solution ‐ namely, Solidor > Diadem > Leanda. Hence, for these cultivars, the nutrient solution methods used appear adequate for selecting plants that are more tolerant to Al in strongly acid soils. Additional study is needed to assess the value of this method for screening a broad range of germplasm.

Superior tolerance of the Solidor cultivar to acid soil was associated with significantly higher concentrations of N in the grain. Hence, results suggest that selecting for acid soil or Al tolerance may increase N efficiency in oats.