Advanced Materials Research Vols. 518-523

Abstract: The effects of three different fertilization patterns including single chemical fertilizer(DH), chemical-organic fertilizer(HY), and single organic fertilizer (DY),no fertilizer(CK) on soil microbial biomass, soil organic carbon content, yield and soil respiration flux in ridge cultivation maize fields in the West Liaohe region were studied. The results showed that soil microbial biomass, organic carbon content, yield and soil respiration flux under HY were higher than the rest of other treatments in 2005 and 2006. The varying order of soil microbial total biomass performed as HY>DY>DH>CK on the ridge-tillage maize farmland. The soil total nitrogen concentration, organic carbon concentration and respiration of HY were significantly higher than the rest of other treatments (p HY> DH > CK; the order of biological yield was DH>HY>DY> CK; the order of grain yield was HY>DH>DY> CK and the economic coefficient of HY was the highest in both years.

Abstract: The characteristics as well as the correlation between runoff and erosion was studied under 3 kinds of cover conditions of bare-slope, artificial grass slope and ecological-restoration slope with 20°slope gradient by runoff scouring intensities of 9l/min. The results showed that: (1) Sediment yield which sourced from artificial grass slope and ecological-restoration slope was separately decreased by 95% and 98% than bare slope, and the runoff reduced by 20% and 50% than bare slope respectively; The infiltration rates of the two kinds of grass slope were higher than the bare slope by 38.32% to 51.10% and 114%; (2) Sediment and runoff process showed that the stable state appeared respectively at 26min, 18min and 6min under bare slope, artificial grass slope and ecological-restoration slope, the amount of runoff was bare slope> artificial grass slope > ecological-restoration slope. (3) For bare slope and artificial grass slope, the relationship between sediment and runoff, sediment and the drag coefficient which both showed a negative correlation, but the correlation which from the ecological-restoration slope wasn’t obvious, so, further studies should carry out to promote runoff-sediment relations on ecological-restoration slope.

Abstract: The Yellow River Delta of China is a unique region with vulnerable ecosystems and under the most pressure from various risk sources. In recent years, this region has experienced rapid economic growth. However, the delta is vulnerable to environmental hazards and is seriously affected by such natural and anthropogenic hazards as coastal erosion, land subsidence, saltwater intrusion, soil salinization and groundwater pollution due to natural disasters and human activities, thereby increasing the risk of environmental degradation in the Yellow River Delta.

Abstract: Soil erosion has been recognized as one of the major environmental problem in red soil region of southern China. The spatial variation of soil erosion was studied using 137Cs technique at three sites (site A, site B, site C) under different type of land use in Jiangxi province. To understand the spatial distribution of soil erosion is important for taking proper soil and water conservation measures. 280 samples were collected at three sites. Medium-term average soil erosion rates estimated for dry farmland is 83.1 kg ha-1 a-1 at site A, and that for paddy fields with terraces on the middle-lower slope is 79.2 kg ha-1 a-1 at site B. Among the uncultivated lands, the average soil erosion rate of bare land is 3700 kg ha-1 a-1 on the upper slope at site A, that of woodland covered with masson pines on the upper slope is 1106 kg ha-1 a-1 at site B and that of economic forest that covered with orchard is 1380.5 kg ha-1 a-1 at site C. On the whole, the soil erosion rate of cultivated land is lower than that of uncultivated land. Bare land, woodland and orchard are the three main sources of soil erosion in red soil region of southern China. Protective measures of cultivated land, such as terraces, field ridge and ditch beside the land, had been demonstrated effectively in controlling soil erosion. The findings provide more information on agricultural land under different type of land use and managed measures which play an important role in controlling the soil loss in Southern China to a certain degree.

Abstract: Inherent anisotropy and induced anisotropy are two main influencing factors on the engineering properties of granite residual soil. When preparing specimens of granite residual soil for undrained triaxial tests, large-sized specimens can be used to weaken the influence of sampling disturbance and inherent anisotropy, and K0 consolidation is adopted to restore the soil specimens to the state of induced anisotropy. The experimental results indicate that, specimen size has no significant influence on the determination of static lateral pressure coefficient k0, while specimen size and consolidation method obviously affect the stress-strain relationship and shear strength indices of granite residual soil. Undrained triaxial tests using large-sized specimens and the method of K0 consolidation can provide parameters more suitable for engineering practice.

Abstract: 65 landslides were interpreted from multi-source satellite image and investigation. And then, the seven factors that influence landslide susceptibility, including stratum, NDVI, faults, drainage, DEM, gradient and aspect were created in raster data format based on GIS and calculated the proportion of landslide disasters in each factors by its CF value using the certainty factor analysis method.

Abstract: The method of measuring saturated soil hydraulic conductivity by using permeating bucket is easy and simple and the instrument is cheap. The water volume must be measuring for many times, meanwhile the water must be added on the top of permeating bucket to sustain the water layer thickness. Based on the principles of supplying water in the fixed water head by Marriott bottle, the method mentioned above is improved, which can reduce the experiment work and improve the experiment accuracy.

Abstract: In this paper, we used MODIS remote sensing image data of Songnen Sandy Land in July 2000 and 2010, extracted the value of MSAVI and vegetation cover index. Based on their values, degrees of desertification were classified including: un-desertification, micro-desertification, mild desertification, moderate desertification and severe desertification. The result show that the area of the desertification decreased in the past 10 years. The desertification is under a decreasing trend.

Abstract: A kind of double-coated environmental friendly fertilizer was prepared by urea as a core, well-mixed keratin and oxidation starch as an inner coating, and superabsorbent polymer as the outer coating. The influence of water absorbency, water retention, and the slow-release behavior of the study fertilizer were investigated. 0.01M CaCl2 immersion extraction and Kjeldahl digestion method were used to measure the content of nitrogen. And the result showed that the nutrient release was 72wt% on the thirtieth day. This result corresponded with the standard of slow release fertilizers of the Committee of European Normalization (CEN) [1]. Keratin and oxidation starch were biodegradable polymer and nontoxic. Both the properties of the materials and the result of the slow-release behavior suggested a new kind of excellent, environmental friendly, slow-release fertilizer.

Abstract: Deformation amount is depended on area position for approximate condition on engineering geology. Deformation amount is small as radius of curvature become small, conversely large. This paper studies severe plastic deformation reason of slope body. Landsliding reason of the side slope corner area is the rain soaked softening effect for the lower part of the clay rock special slope form. Therefore, abnormal deformation is produced. Slope stability is related slope angle, sometimes related secondary softening effect of rain water. So, key measures of slope safety are ensured for controlling the rain soaked softening effect.