Effect of biochar on cadmium bioavailability and uptake in wheat (Triticum aestivum L.) grown in a soil with aged contamination.

Biochar application increased the growth and yield and reduced cadmium in drought stressed wheat grown in an aged contaminated soil.

Contrasting effects of biochar, compost and farm manure on alleviation of nickel toxicity in maize (Zea mays L.) in relation to plant growth, photosynthesis and metal uptake

Soil degradation by salinity and accumulation of trace elements such as cadmium (Cd) in the soils are expected to become one of the most critical issues hindering sustainable production and feeding the increasing population. Biochar (BC) has been known to protect the plants against soil salinity and heavy metal stress. A soil culture study was performed to evaluate the effect of BC on wheat (Triticum aestivum L.) growth, biomass, and reducing Cd and sodium (Na) uptake grown in Cd-contaminated saline soil under ambient conditions. Soil salinity decreased the plant growth, biomass, grain yield, chlorophyll contents, and gas exchange parameters and caused oxidative stress in plants compared with Cd stress alone. Salt stress increased Cd and Na uptake and reduced the potassium (K) and zinc (Zn) uptake by plants. AB-DTPA-extractable Cd and soil electrical conductivity (ECe) increased under salt stress compared to the soil without NaCl stress. Biochar application improved the plant growth and reduced the Cd and Na uptake except in plants treated with higher BC and salt stress (5.0% BC + 50 mM NaCl). Biochar application reduced the oxidative stress in plants and modified the antioxidant enzyme activities, and reduced the bioavailable Cd under salt stress. The positive effects of BC under lower salt stress while the negative effects of BC under higher BC and salt levels indicated that BC doses should be used with great care in higher soil salinity levels simultaneously contaminated with Cd to avoid the negative effects of BC on growth and metal uptake.

Effect of biochar on alleviation of cadmium toxicity in wheat (Triticum aestivum L.) grown on Cd-contaminated saline soil

Landslides are one of the most important environmental hazards occur naturally or human-induced with large-scale social, economic, and environmental impacts. Landslide susceptibility zoning, which has been widely performed in the last decades, allows identifying spatial prediction of areas of landslides, which could be used for land use planning and land management. The present study was conducted as a review with the aim of investigating the research background of landslide susceptibility in the world during the period of 2005–2016. The results showed that the publication of papers related to landslide susceptibility during the period of investigation has been on the rise, and China has produced a larger number of papers and authors (13% of total). In addition, this article reviews the most popularly used models and the most frequently used input factors. Among different models, the logistic regression has been used as the most common method for assessing landslide susceptibility in 28.4% of the articles, and the slope gradient is considered as the most important conditioning factor in landslide occurrence in 94.2% of the articles. Finally, it is concluded that the recent technological developments in the field of remote sensing, computing technologies and Geographic Information Systems (GIS), the increased data availability, and the awareness has arisen among media and recent policy developments are important elements for increasing the research interest in landslide susceptibility.

Analysis and evaluation of landslide susceptibility: A review on articles published during 2005-2016 (periods of 2005-2012 and 2013-2016)

Landfilling is the most common method used for disposal of solid waste and selection of suitable landfill for municipal solid waste management is important part of urban planning. The aims of this paper are determining the constraints, criteria for landfill site selection according to present legislations in Iran, zoning potential of Shabestar city for construction of municipal landfill and selection of the most suitable sites. At first, by reviewing of internal and external literature, the criteria which were necessary to achieve the aims of study were determined. Then, conceptual model of landfill site selection steps and process was developed. After that, the required maps were collected from relevant organizations and prepared using geographic information systems (GIS) tool in order to use in the next steps. Finally, all criteria maps were standardized by fuzzy functions and entered in mathematical combination model. In this study, the fuzzy functions in ArcGIS 10 including linear, large, small and Gaussian were used. Weighting of criteria was performed by analytical hierarchy process (AHP) method using expert choice application and weighted linear combination (WLC) was chosen for integration of maps. Preliminary results of zoning showed that nearly 6.2 % of the study area has good suitability for municipal landfill. To select the best site among the candidate sites for Shabestar city, at first the sensitive analysis was performed and then the best site was selected based on required area, soil depth, dominant wind direction and visibility from residential area.

Sara Bahrani

Papers

Modeling landfill site selection by multi-criteria decision making and fuzzy functions in GIS, case study: Shabestar, Iran