Comparison of Soil Nitrogen Availability Indices under Two Temperate Forest Types

To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross N mineralization rate （GNR） in mineral soils （0-10 cm） from six forest stands located in central Germany were determined and compared with two sampling times： April and November. Additionally, soil density fractionation was conducted for incubated soils （with addition of ^15NH4-N and glucose, 40 days） to observe the sink of added ^15N in different soil fractions. The study showed that Nmic and NNR in most stands differed significantly （P 〈 0.05） between the two sampling times, but not GNR, SAN and SON. In November, no close relationships were found between GNR and other N indices, or between Nrnic, SON, and SAN and forest type. However, in April, GNR was significantly correlated （P 〈 0.05） with Nmic, SAN, and NNR along with Nmlc under beech being significantly higher （P 〈 0.05） than under conifers. Furthermore, density fractionation revealed that the light fraction （LF, 0.063-2 mm, 〉 1.7 gcm^-3） was not correlated with the other N indices. In contrast, results from the incubation study proved that more 15N was incorporated into the heavy fraction （HF 〈 0.063 ram, 〉 1.7 g cm^-3） than into LF, indicaing that more labile N existed in HF than in LF. These findings suggested that attention should be paid to the differences existing in N status between agricultural and forest soils.

Effects of Groundwater with Various Salinities on Evaporation and Redistribution of Water and Salt in Saline-sodic Soils in Songnen Plain,Northeast China

Groundwater mineralization is one of the main factors affecting the transport of soil water and salt in saline-sodic areas.To investigate the effects of groundwater with different levels of salinity on evaporation and distributions of soil water and salt in Songnen Plain,Northeast China,five levels of groundwater sodium adsorption ration of water(SARw)and total salt content(TSC mmol/L)were conducted in an oil column lysimeters.The five treated groundwater labeled as ST0:0,ST0:10,ST5:40,ST10:70 and ST20:100,were prepared with NaCl and CaCl2 in proportion,respectively.The results showed the groundwater evaporation(GWE)and soil evaporation(SE)increased firstly and then decreased with the increase of groundwater salinity.The values of GWE and SE in ST10:70 treatment were the highest,which were 2.09 and 1.84 times the values in the ST0:0 treatment with the lowest GWE and SE.There was a positive linear correlation between GWE and the Ca^(2+)content in groundwater,with R^(2)=0.998.The soil water content(SWC)of ST0:0 treatment was significantly(P<0.05)less than those of other treatments during the test.The SWC of the ST0:0 and ST0:10 treatments increased with the increase of soil depth,while the other treatments showed the opposite trend.Statistical analysis indicated the SWC in the 0–60 cm soil layer was positively correlated with the groundwater TSC and its ion contents during the test.Salt accumulation occurred in the topsoil and the salt accumulation in the 0–20 cm soil layer was significantly(P<0.05)greater than that in the subsoil.This study revealed the effects of the salinity level of groundwater,especially the Ca^(2+)content and TSC of groundwater,on the GWE and distributions of soil water and salt,which provided important support for the prevention and reclamation of soil salinization and sodificaton in shallow groundwater regions.

Review of Sodic Soil Reclamation with a Snapshot of Current Research Activity

For centuries, reclamation of sodic soils has been an essential part of cropping practices in several parts of the world. Parallel to increasing population, the need for new cropland constantly re-evaluates land suitability concepts. Therefore, the importance of sodic soils as potential croplands is increasing worldwide. Although theoretically farmers can choose from a wide variety of reclamation options, according to profitability, business plans, and human and financial resources, in practice, few reclamation methods are applied at large scale. This article touches on the early history, 20th Century intensive research, and current trends of sodic soil reclamation. New approaches such as leaching, chemical amendments, addition of organic material, and biological and microbial improvements are discussed, and also brand-new approaches are reviewed. The early history is reviewed using historical books, the achievements of the last hundred years using basic technical literature, mostly books, and the current approaches of our time with fresh publications, mostly papers and two very recent conferences published in English.

Studying the Condition of Soil Protection Agrolandscape in Ukraine Using Remote Sensing Methods

The article reviews the scientific approaches to monitoring of soil condition on the soil protection agrolandscape. In 1980s, the contour-meliorative soil protection system was established on the selected fields in Ukraine. The objective of the current research was to determine the capabilities of satellite survey to identify the changes of soil cover that had occurred on these fields during the past 25 years. Soil erosion processes are very dynamic, therefore it is essential to use time-series of operative satellite images to track those changes. Rills on the fields, caused by water erosion, are clearly identified on high-resolution satellite data. Erosion causes the decrease of humus content, which affects soil reflection values. This in turn leads to a corresponding change of color shade on satellite images. The research allowed to determine correlation between remote sensing data and soil organic carbon content and to acquire a mathematical model which describes this correlation. The condition of the agrolandscape soils was assessed using the regression model, which helped to evaluate erosion risk for different areas of the test polygon. The visual interpretation of satellite imagery led to a conclusion about a damaging effect of erosion on protective forest belts and accordingly on fields＇ soil cover and crops. Visual analysis results were approved by field research. Photos taken during the field research indicate an unsatisfactory status of forest belts and a devastating effect of eroding water flows. These are the results of irresponsible land use and constant violation of methodical principles of the contour-meliorative system organization. The article concludes that the use of time-series of high-resolution satellite imagery allows monitoring the condition of soil protection agrolandscape, in particular the forest belts＇ status soil cover conditions and their change over time. The research results can be used as an informational basis for the soil protection agrolandscape monitoring system.

The Digital Mapping of Ukrainian Soils on the Base of High Resolution Space Images

The first Ukrainian using experience of multispectral space scanning for digital soil mapping is described in this paper. Methodical approaches for detailed soil observation of Ukrainian forest regions are elaborated based on modem mapping principles. For the first time in Ukraine, digital soil maps based on GIS （geographic information system） were obtained for individual farms. In GIS based on space images and digital relief models, the medium-scale and large-scale soil maps were created by geo-statistical methods. According to elaborated methods, modem digital soil mapping should provide all combined works： remote sensing and traditional soil observations. The modem digital soil mapping should be based just on quantitative principles： on remote sensing data, geomorphologic field parameters, and chemical analyses. The methodological approaches, which were used for the first time in Ukraine during digital soil mapping by remote sensing methods, are described in this paper.

Evolution of Petroleum Hydrocarbons in Soil Polluted with Crude Oil Treated with a Natural Product

Bioremediation of petroleum hydrocarbons contaminated/polluted soils has been recognized as an efficient, economic, versatile and environmentally good treatment. This method is limited by the microorganisms activity in degrading the spills hydrocarbons. Low solubility of the hydrocarbons involves low bioavailability to microorganisms. The main objective of this research is to increase biodegradation of petroleum hydrocarbons by treating the crude oil polluted soil with the natural biodegradable product and bacterial inoculum. Biodegradation was quantified by total petroleum hydrocarbons （TPH） analyses. The paper presents data obtained in biodegradation process of an artificial polluted soil with 5% and 10% crude oil, treated with a natural biodegradable product and bacterial inoculum during two years of experiment. Biodegradation process takes time to rehabilitate and reuse of the soil in agricultural scopes.

The contribution of the European Society for Soil Conservation (ESSC) to scientific knowledge, education and sustainability

Soil is an integral component of the global environmental system which supports the quality and diversity of terrestrial life on Earth.Therefore,it is vital to consider the processes and impacts of soil degradation on society,especially on the provision of environmental goods and services,including food security and climate change mitigation and adaptation.Scientific societies devoted to soil science play significant roles in reducing soil degradation and promoting soil conservation by advancing scientificknowledge,education and environmental sustainability.The ESSC was founded on 4 November 1988,with the aims to:1.Support research on soil degradation,soil protection and soil and water conservation.2.Provide a network for the exchange of knowledge about soil degradation processes and soil conservation research and practises.3.Produce publications on major issues relating to soil degradation and soil and water conservation.4.Advise regulators and policy-makers on soil issues,especially soil degradation,protection and conservation.The societal challenges that can be addressed through better soil protection,advancing knowledge and scientific approaches to soil protection and sustainable management,mean the ESSC embraces the on-going development,application,review and constructive criticism of highly innovative scientific soil conservation methods,In this context,the ESSC analyses and publicizes the roles and functions of soil in natural and human-modified systems and the functional optimization of soils to ensure sustainable environmental protection.'The thin layer of soil that forms a patchy covering over the continents controls our awn existence and that of every other animal of the land' (Rachel Carson (1962) in'Silent Spring).

伪潜育土季节性滞水条件下大冷杉毫根动态的研究(Abies grandis Lindl.)

本文对一个25年生大冷杉林在伪潜育土至45cm矿质土壤里,从1987年晚秋滞水期至1988年生长旺盛期的毫根量动态及化学组成变化进行了研究。 滞水期土壤中死根量(5558kg DS/ha)显著高于活根量(3594kg DS/ha)。生长旺盛期初,活根量增加约50％,死根量降低约27％。经过夏季至生长旺盛期末,活根量仍略有增加,死根量继续降低。毫根化学组成分析显示,滞水期活根中K、Mg及Zn离子含量显著低于生长旺盛期,Mn离子含量则明显高于生长旺盛期。这一结果表明,除了与季节性相关的生长节奏因素外,大冷杉毫根生物量的变化主要是由滞水状况所致。

Subsurface accumulation of CaCO3 and Cl- from groundwater under black locust and poplar plantations

When conditions are similar,more water evaporates from forest plantations than herbaceous vegetation,thereby affecting hydrological fluxes and ion transport in the soil.The vertical distribution of CaCO3 and Cl^-ions shifts due to afforestation.The effect of groundwater depth and clay content were studied in the Great Hungarian Plain where forest area has been increasing for decades by analyzing soil and groundwater samples from stands of black locust(Robinia pseudoacacia,11 plots)and poplar(Populus spp.,11 plots).All study sites contained one herbaceous(control)and one or more forested plots.CaCO3 and Cl^-ions accumulated in the soil profile in greater quantities under tree cover than in the controls.The scale of this process largely depended on the species and on soil and ion properties.Under black locust,Cl^-accumulated between 1.3 and 6.3 m,with a maximum difference of 0.3 pCl unit(pCl is Cl^-activity,the negative of the logarithm to base 10 of the concentration of the chloride ion,determined using an ion-selective electrode,it is a dimensionless quantity.),while the difference in CaCO3 accumulation was at most 3.5%in some layers,compared to control plots.This result may be explained by the difference in the mobility of Ca+and Cl^-ions.Different mechanisms were noticeable under poplar plantations due to their higher water uptake:Cl-accumulation was detected below 0.9 m to the groundwater with a maximum difference of 0.5 pCl units,while CaCO3 accumulation was continuous at depths of 2.3–6.8 m with a maximum difference of 8.4%,compared to the controls.With increasing clay content,there was a discernible effect on CaCO3 and Cl-accumulation under black locust,but not observed under poplars.These differences were explained by the differences in water uptake mechanisms and root patterns of the two species and the different mobility of Ca2^+and Cl-ions.

Organic Carbon Changes Over 40-years in a Haplic Luvisol Type Farmland in Hungary

It is well known the effect of fertilizer applications in Haplic Luvisols after crop production, but long term changes in precipitation and soil organic carbon are not well documented. Study aimed to determine the effect of precipitation and fertilization （NPKCaMg） on the changes in soil organic carbon （SOC） in a long-term field experiment set up in Nyirlugos （Nyirs6g region, Hungary： N： 47°41′60″ and E： 22°2′80″ since 1962） on a Haplic Luvisol. Over the 40 year period, from 1962 to 2002, SOC pool values ranged between 2.32 and 3.36 mg kg-1. On the untreated control plots the values remained nearly constant （3.31 mg kg-1, ± 0.29 mg kg1 and 0.52 mg kg-1）. NPKCaMg fertilization resulted in a significant （P 〈 0.001） decline （16.6%） in SOC in comparison to the control plots in the Ist 20-year interval, while in the 2nd 20-year period a significant （P 〈 0.001） increased （up to 31.9%） was noticed. During the 40 experimental years the seasonal correlations （R2 among SOC （mg kgl）, WHY and SHY precipitation （mm） ranged from 0.3343 to 0.9078 （on the P 〈 0.001 significance level）. The correlations （R2） on the influence of NPKCaMg fertilization on SOC （mg kg-1） and precipitation （mm） were significant （P 〈 0.001）： the means for WHY, SHY and over the 40 years were 0.4691, 0.6171 and 0.6582, respectively. Organic carbon reserves （mg kg-1） in soils decreased linearly as precipitation increased （from 3.22 to 7.27 mm yr-1）. In case this trend-increasing precipitation caused by climate change reduces SOC in arable soils-will continue, and is aggravated by warming temperatures and a more altering climate （as predicted by climate change forecasts）, the livelihoods of many Hungarian and European farmers may be substantially altered.

Coupling the 4M crop model with national geo-databases for assessing the effects of climate change on agro-ecological characteristics of Hungary

The 4M crop model was used to investigate the prospective effects of climate change on the agro-ecological characteristics of Hungary.The model was coupled with a detailed meteorological database and spatial soil information systems covering the whole territory of Hungary.Plant-specific model parameters were determined by inverse modeling.Future meteorological data were produced from the present meteorological data by combining a climate change scenario and a stochastic weather generator.Using the available and the generated data,the present and the prospective agro-ecological characteristics of Hungary were determined.According to the simulation results,average yields will decrease considerably(-30%)due to climate change.The rate of nitrate leaching will prospectively decrease as well.The fluctuations of both the yields and the annual nitrate leaching rates will most likely increase approaching the end of the twenty-first century.On the basis of the simulation results,the role of autumn crops is likely to become more significant in Hungary.The achieved results can be generalized for more extended regions based on the concept of spatial(geographical)analogy.

The potential application of red mud and soil mixture as additive to the surface layer of a landfill cover system

Red mud, the by-product of aluminum production, has been regarded as a problematic residue all over the world. Its storage involves risks as evidenced by the Ajka red mud spill,an accident in Hungary where the slurry broke free, flooding the surrounding areas. As an immediate remediation measure more than 5 cm thick red mud layer was removed from the flooded soil surface. The removed red mud and soil mixture（RMSM） was transferred into the reservoirs for storage. In this paper the application of RMSM is evaluated in a field study aiming at re-utilizing waste, decreasing cost of waste disposal and providing a value-added product. The purpose was to investigate the applicability of RMSM as surface layer component of landfill cover systems. The field study was carried out in two steps： in lysimeters and in field plots. The RMSM was mixed at ratios ranging between 0 and 50% w/w with low quality subsoil（LQS） originally used as surface layer of an interim landfill cover. The characteristics of the LQS ＋ RMSM mixtures compared to the subsoil（LQS） and the RMSM were determined by physical–chemical, biological and ecotoxicological methods. The addition of RMSM to the subsoil（LQS） at up to 20% did not result any ecotoxic effect, but it increased the water holding capacity. In addition, the microbial substrate utilization became about triple of subsoil（LQS） after 10 months. According to our results the RMSM mixed into subsoil（LQS） at20% w/w dose may be applied as surface layer of landfill cover systems.

Effect of irrigation water containing arsenic on elemental composition of bean and lettuce plants cultivated in calcareous sandy soil

Background:The uptake of arsenic by vegetables from soil irrigated with arsenic enriched groundwater poses a major health hazard.The edible portion of these vegetables transfer arsenic to the human beings.The uptake of arsenic was studied in bean(Phaseolus vulgaris L.)and lettuce(Lactuca sativa L.)in a controlled greenhouse pot culture with calcareous sandy soil as substrate.The plants were irrigated with water containing sodium arsenate at concentrations 0.1,0.25 and 0.5 mg L^(-1).The total arsenic concentration of the different plants parts was determined by ICP-MS,following microwave-assisted acid digestion.The change in plant biomass production and essential macroelements(Mg,P,K)and microelements concentration(Fe,Mn,Cu,Zn)was also studied.Results:The As concentration in the bean was in the order:root>stem>leaf>bean fruit and in lettuce:root>leaves.At the highest dose(0.5 mg L^(-1))the As concentration in the bean fruit and lettuce leaves was 22.1μg kg^(-1)and 1207.5μg kg^(-1)DW,respectively.Increasing As concentration in the irrigation water resulted in decreased edible biomass production in bean,while in lettuce the edible biomass production increased.Neither plant exhibited any visible toxicity symptoms.No significant change was observed in the macro and microelements concentration.The total and the water-soluble arsenic in soil amounted to 3.5 mg kg^(−1)and 0.023 mg kg^(−1),respectively.The transfer factor was found to increase with increase in the As treatment applied.The transfer factor range for bean from root to fruit was 0.003–0.005,and for lettuce from root to leaves was 0.14–0.24.Conclusion:Considering the FAO-WHO recommended maximum tolerable daily intake(MTDI)limit of 2.1μg kg^(-1)body weight,and the biomass production,both plants should not be cultivated at As treatment level higher than 0.1 mg L^(-1).

Groundwater uptake of different surface cover and its consequences in great Hungarian plain

Introduction:Forest cover in Hungary has increased from 1.1 to 2.0 million hectares during the last century.The EU(European Union)promotes further afforestation;thus,15,000–18,000 ha are being forested each year,mainly in the Hungarian Great Plain.In terms of species used for afforestation,poplar plantations are preferred over native oak woodlands.The groundwater uptake of trees can be a significant water balance element of forested areas in shallow groundwater environments within the Hungarian Great Plain.Forests can cause water table depressions and subsurface salt accumulation in areas with negative water balance.This study examined the hydrological impact of forest cover in the Hungarian Great Plain.Within the framework of this research,climatic water balance,water table depth and salinity,subsoil layering,tree species and stand age were analysed as influencing factors.This paper compares the effect which an oak forest,a poplar plantation and a pasture have on groundwater uptake and salt accumulation.Results:The water table level was roughly 0.4–0.5 m lower beneath the oak forest and the poplar plantation than it was beneath the pasture.Forest groundwater use was 1.5–2 times higher than that of grassland.Groundwater uptake of oak forest was greater than that of poplar plantation during the monitoring period.Salt accumulation,which shows water use in the longer run,was slightly higher for poplar in deeper layers.Conclusions:The greater amount of groundwater used by trees does not lead to a higher salt uptake as only a slight accumulation of salt was measured beneath the forests.Overall,hybrid poplar was slightly less favourable than native oak when considering salinization effects.However,even greater groundwater uptake by trees over longer timescales could cause more significant salt accumulation under pronounced drought conditions due to climate change.

Earth observation and geospatial big data management and engagement of stakeholders in Hungary to support the SDGs

To support the monitoring and reporting processes during imple-mentation of the Sustainable Development Goals,well-developed,commonly recognized Earth observations and geospatial data,methods,innovations,committed professionals,and strong sus-tainability policies are necessary.This article informs the readers on the Earth observation and geoinformation developments and innovations,and on the engagement of profession,academy and governance to support implementation of the Sustainable Development Goals in Hungary.Description,analyses and critical assessments are given on the elements selected from Hungarian sustainable-oriented Earth observation and geospatial novelties:(a)Working Group for Sustainable Development mission and national sustainabilitypolicy,(b)international partnerships,domestic activities and achievements,(c)status of the professional education,(d)spatial databases and services to support implementation of the sustain-able development,(e)a case study on the internationally recog-nized soil geoinformation system,(f)national Earth Observation Information System and perspectives of its applications for mon-itoring the sustainability.The article conclusion strongly advises the Hungarian realization of(a)institutionalization of the Earth observation and geospatial tools and capacity for sustainable development,(b)their use in integration with statistical data,(c)establishment of national spatial information infrastructure and(d)development and spreading of the use of big data.

Urban-induced changes in tree leaf litter accelerate decomposition

Introduction:The role of urban areas in the global carbon cycle has so far not been studied conclusively.Locally,urbanization might affect decomposition within urban boundaries.So far,only few studies have examined the effects of the level of urbanization on decomposition.This study addresses the influence of the level of urbanization on decomposition processes.It explores whether potential influences are exerted through leaf litter quality alterations or through direct effects of decomposition site’s level of urbanization.Leaf litter of five different tree species was sampled at urban and periurban sites.Decomposition of this litter was analyzed in three different experiments:a climate chamber incubation,a reciprocal litterbag transplant at urban and periurban sites,and a common garden litterbag transplant.Results:Decomposition site’s level of urbanization did not show a significant effect.However,in all species,when significant differences were observed,leaf litter of urban origin decomposed significantly faster than leaf litter of periurban origin.This effect was observed in all three experiments.In the reciprocal litter transplant experiment,62%±3%mass loss in litter of urban origin compared to 53%±3%in litter of periurban origin was observed.The difference was not as pronounced in the other two experiments,with 94%±1%mass loss of litter originating in urban habitats compared to 92%±1%mass loss of litter originating in periurban habitats in the common garden experiment and 225±13 mg CO2 released from litter originating in urban habitats compared to 200±13 mg CO2 released from litter originating in periurban habitats in the climate chamber incubation.Conclusions:We conclude that the level of urbanization affects decomposition indirectly through alterations in leaf litter quality even over short urban to periurban distances.

Input database related uncertainty of Biome-BGCMuSo agroenvironmental model outputs

Gridded model assessments require at least one climatic and one soil database for carrying out the simulations.There are several parallel soil and climate database development projects that provide sufficient,albeit considerably different,observation based input data for crop model based impact studies.The input database related uncertainty of the Biome-BGCMuSo agro-environmental model outputs was investigated using three and four different gridded climatic and soil databases,respectively covering an area of nearly 100.000 km2 with 1104 grid cells.Spatial,temporal,climate and soil database selection related variances were calculated and compared for four model outputs obtained from 30-year-long simulations.The choice of the input database introduced model output variability that was comparable to the variability the year-to-year change of the weather or the spatial heterogeneity of the soil causes.Input database selection could be a decisive factor in carbon sequestration related studies as the soil carbon stock change estimates may either suggest that the simulated ecosystem is a carbon sink or to the contrary a carbon source on the long run.Careful evaluation of the input database quality seems to be an inevitable and highly relevant step towards more realistic plant production and carbon balance simulations.