Role of the different planting age of seabuckthorn forests to soil amelioration in coal mining subsidence land

To investigate the effects of seabuckthorn(Hippophae rhamnoides)on soil amelioration,using the space replacement method,soil physical and chemical indexes as well as the microorganism quantity and soil enzyme activities were analyzed.The results showed that:the soil bulk density of surface soil decreased and soil porosity and field capacity increased after afforestation with seabuckthorn.The plant was found to effectively reduce the soil pH,increase the soil conductivity,soil organic matters and available nutrients.Soil microorganism quantity,soil enzyme activities were both higher in 0-20 cm layer than in 20-40 cm layer.With the increase years of remediation with seabuckthorn,the quantity of soil microorganism and enzyme activities were increasing to a higher level 5 to 8 years later.Our study indicates that seabuckthorn can effectively improve soil physical and chemical properties,increase the quantity of soil microorganisms and enzyme activities,which is of great significance for the ecosystem restoration in mining areas.

Bio-amelioration of alkali soils through agroforestry systems in central Indo-Gangetic plains of India

A long-term field study was initiated during 1995 at Central Soil Salinity Research Institute, Regional Research Station, Lucknow （26047＇58＂ N and 80°46＇24＂ E） to analyze the effect of agroforestry systems on amelioration of alkali soils. Three agroforestry systems （pas- toral, silvipastoral and silvicultural） were compared with the control where no agroforestry system was introduced. Tree-based silvicultural and silvipastoral systems were characterized by tree species Prosopis juliflora and Acacia nilotica along with grass species Leptochloafusca, Panicum maximum, Trifolium alexandrium and Chloris gayana. Growth of ten-year-old Prosopis juliflora and Acacia nilotica planted in combi- nation with grasses was significantly higher over the silviculture system with the same species. Tree biomass yields of P. juliflora （77.20 t·ha-1） and A. nilotica （63.20 t·ha-1） planted under silvipastoral system were significantly higher than the sole plantation of （64.50 t·ha-1 and 52.75 t·ha-1）. Fodder yield under the pastoral system was significantly higher than the silvipastoral system during initial years but it was at par with that of silvipastoral systems after eight years of plantation. The microbial biomass carbon in the soils of silvipastoral systems was significantly higher than in soils under sole plantation of trees and control systems. The Prosopis-based silvipastoral system proved more effective in reduc- ing soil pH, displacing Na＋ from the exchange complex, increasing or- ganic carbon and available N, P and K. Improvement in soil physical properties such as bulk density, porosity, soil moisture and infiltration rate was higher in the Prosopis-based silvipastoral system than in the silviculture system or control On the basis of biomass production and improvement in soil health due to tree ＋ grass systems, silvipastoral agroforestry system could be adopted for sustainable reclamation ofhighly alkali soils.

Effects of different plantation types on soil properties after vegetation restoration in an alpine sandy land on the Tibetan Plateau, China

Large areas of Artemisia ordosica Krasch., Caragana korshinskii Kom., and Caragana intermedia Kuang and H. C. Fu plantations were established on moving sand dunes in the Gonghe Basin （northeastern Tibetan Plateau） for vegetation restoration. Elevating our understanding of the changes in soil characteristics after the establishment of different plantation types can be useful in the context of combating deserdfication. To assess the effects of these plantation types on the restoration of sandy land, we measured soil physical-chemical properties at four depths （0-5, 5-10, 10-20, and 20-50 cm） in each of the three plantation types and also in non-vegetated moving sand dunes （as control sites）. Generally, the establishment of A. ordosica, C korshinskii and C intermedia plantations on sand dunes has greatly ameliorated soil quality in the Gonghe Basin. Specifically, relative to the moving sand dunes, shrub plantation has increased the silt and clay contents, total porosity and water holding capacity, soil organic matter, total nitrogen, total phosphorus and total potassium contents. The calculated soil quality index suggested that in the Gonghe Basin, C. intermedia is the best choice for soil amelioration. In all the three plantation types, soil amelioration mainly occurred in the shallow depths.

Effect of EM Bokashi application on control of secondary soil salinization

In order to ameliorate saline-alkaline soil, EM Bokashi has been applied to rice production in conjunction with subdrainage in Ningxia Autonomous Region and Zhejiang Province. The preliminary results can be summarized as follows： EM Bokashi can increase soil organic matter content, improve soil porosity and permeability, and raise the soil＇s levels of available nutrients; and EM Bokashi combined with subdrainage treatment is more effective in controlling secondary soil salinization and raising the grain yield and quality than other treatments. The results suggest that EM Bokashi can reduce the necessary amount of chemical fertilizer application, thereby improving the agricultural environment, and that the introduction of EM Bokashi into systems of secondary soil salinization control systems has resulted in significant benefits.

SOIL SALINITY CONTROL REGARDING SUBSURFACE WATER REGULATION IN NORTH CHINA PLAIN

The North China Plain (NCP) lying along the eastern coastal area withgeogriaphical coordinates 100°to 120°and 30° to 40°W, is one of the mostimportan agncultural ngons in China. A problem in soil salmization has beenfound in vast areas along the lower reaches of the Yellow hiver and north of it. After30 years of work on saline soil amelioration, 2.0 million ha has been improved,accounting for over 60 percen of the total ongnal saline soil area. Ths achievetnenthas ban obtained in close relation to water conservancy work. The author analyzessalthezation amelioration by using measures concerning subsuffoce water regulation.Ih addition to water conservancy measures, thes paper also descnbes acomprehensive way to ameliorate salthezation in northem NCP. Finally, the authorstresses the necessity of combining all measures together into a whole system forsolving salinization problems in northem NCP.

Impact of Ash-Fertilization and Soil Preparation on Soil Respiration and Vegetation Colonization on Cutaway Peatlands

As a result of several decades of peat extraction, the area of cutaway peatlands in Finland totals ca. 50,000 ha. Furthermore, some 2000 - 3000 ha of peatlands are abandoned annually from active peat extraction. Forestry is considered to be their main after-use option. However, since cutaway peat is generally rich in nitrogen, but poor in phosphorus and potassium, soil amelioration measures are needed for successful vegetation and afforestation. Soil preparations bringing mineral soil into peat surface or recycling of ash containing P and K are alternative ways for soil amelioration. We studied the initial effects of soil preparation and ash fertilization on soil CO2-effluxes and colonisation of cutaway peat by vegetation. Oppositely to the previous studies, this study shows that carbon released from the residual peat may be so high that the ash-fertilized cutaway peatlands still act as sources of carbon even after afforestation. However, even though the CO2-effluxes following ash fertilization or soil preparation may occasionally exceed the carbon sequestration into growing tree stands, afforestation mostly compensates the CO2-effluxes if also we take into consideration the below-ground biomass. In conclusion, our study shows that although ash fertilization enhances the CO2-effluxes into the atmosphere, it has beneficial effects on the environment by enabling rapid colonisation of vegetation on these sites which would remain vegetationless for decades without soil amelioration.

The preparation of paddy soil amendment using granite and marble waste: Performance and mechanisms

The wastes generated from themining and processing of granite and marble stone are generally regarded as useless.However,these waste materials were used as the soil amendments for the first time.The functional groups,crystalline structure andmicro-morphology of granite and marble wastes amendments(GMWA)were different from the original wastes demonstrated by X-ray diffractometer(XRD),Fourier transform infrared spectrometer(FTIR)and Scanning electron microscope-energy dispersive spectrometer(SEM-EDS)analyses.With the addition of the amendments,the cation exchange capacity,electrical conductivity and nutrient availability of the soil increased,and the extractable heavy metals of the soil reduced significantly.Under the condition of the addition of 3%amendments,7.0%,99.9%,99.7%and 70.5%of Cu,Pb,Zn and Cd in exchangeable fractions in soil were transformed to the more stable Fe-Mn oxides-or carbonates-bounded fractions.Tessier method and correlation analysis showed that the reduction of extractable metals in the acidic paddy soil can be attributed to the adsorption of available SiO_(2),the co-precipitation induced by the elevated pH value,the complexation induced by Fe-Mn oxides and the cation exchange induced by mineral nutrients.This study provides a new strategy for resource recovery of waste stones and remediation of heavy metal-contaminated soil.

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.

Characteristics of biomass ashes from different materials and their ameliorative effects on acid soils

The chemical characteristics,element contents,mineral compositions,and the ameliorative effects on acid soils of five biomass ashes from different materials were analyzed. The chemical properties of the ashes varied depending on the source biomass material. An increase in the concrete shuttering contents in the biomass materials led to higher alkalinity,and higher Ca and Mg levels in biomass ashes,which made them particularly good at ameliorating effects on soil acidity. However,heavy metal contents,such as Cr,Cu,and Zn in the ashes,were relatively high. The incorporation of all ashes increased soil p H,exchangeable base cations,and available phosphorus,but decreased soil exchangeable acidity. The application of the ashes from biomass materials with a high concrete shuttering content increased the soil available heavy metal contents. Therefore,the biomass ashes from wood and crop residues with low concrete contents were the better acid soil amendments.