Digital Repository for Department of Soil and Sand

Lithospheric-derived resources such as soil texture and coarse fragments are key soil physical properties that contribute to ecosystem services (ES), which can be valued based on "soil" or "mineral" stocks. Soil survey data provides an inexpensive alternative to detailed field measurements which are often labor-intensive, time-consuming, and costly to obtain. However, both field and soil survey data contain heterogeneous information with a certain level of variability and uncertainty in data. This study compares the potential of using field measurements and information from the Soil Survey Geographic database (SSURGO) for coarse fragments (CF), sand (S), silt (Si), clay (C), and texture class (TC) in the surface soil (Ap horizon) for the 147-hectare Cornell University Willsboro Research Farm, NY. Maps were created based on following methods: (a) utilizing data from the SSURGO database for individual soil map unit (SMU) at the field site and using representative or reported values across individual SMU; (b) averaging the field data within a specific SMU boundary and using the averaged value across the SMU; and (c) interpolating field data within the farm boundaries based on the individual soil cores. This study demonstrates the important distinction between mapping using the "crisp" boundaries of SSURGO databases compared to the actual spatial heterogeneity of field interpolated data. Maps of CF, S, Si, C, and TC values derived from interpolated field core samples were dissimilar to maps derived by using averaged core results or SSURGO values over the SMUs. Dissimilarities in the maps of CF, S, Si, C, and TC can be attributed to several factors (e.g., official soil series data being collected from "type locations" outside of the study areas). Correlation plot of clay estimates for each SMU showed statistically significant correlations between SSURGO and field-averaged (r = 0.823, p = 0.003) and field-interpolated clay (r = 0.584, p = 0.028) estimates, but no correlation was found for CF, S, and Si. Ecosystem services provided by quantitative data such as CF, S, Si, and C may not be independent from each other and other soil properties. Key soil properties should also include categorical data, such as texture class, which is used for another key soil property-available soil water ratings. Current valuation of soil texture is often linked to specific mineral commodities, which does not always address the issue of soil based valuation including indirect use value. arabic 19 English 133
Elena Mikhailova, Christopher Post, Patrick Gerard, Mark Schlautman, Michael Cope, Garth Groshans, Roxanne Stiglitz, Hamdi Zurqani, John Galbraith(9-2019)

Current applications of the Ecosystems Services (ES) framework to soils are narrowly defined (e.g., soil-based, pedosphere-based, etc.), and focus on soil properties while treating soil as a closed system. Because soil is an open system, it receives and loses matter across its boundaries within Earth’s spheres (atmosphere, biosphere, hydrosphere, lithosphere, ecosphere, and anthroposphere), which also need to be accounted for in economic analysis. In market economies, the market transforms resources from the Earth’s pedosphere and related spheres into goods and services for societal welfare with non-market institutions mediating human and environmental interactions. These transformations and mediations can result not only in welfare but damages as well. The concept of soil ES and ecosystem disservices (ED) is a human-centered framework, which can be a useful tool in business decision-making. Soil ES (e.g., provisioning, regulation/ maintenance, and cultural) are used to produce goods and services, but the value of these ES and ED are not always accounted for as a part of business decision-making. The objective of this review is to illustrate the monetary valuation of ecosystem services of soil systems (SS) with examples based on the organizational hierarchy of soil systems. The organizational hierarchy of soil systems can be used in economic valuations of soil ES by scale (e.g., world, continent), time (e.g., soil, geologic), qualitative and quantitative degrees of computation (e.g., mental, verbal, descriptive, mathematical, deterministic, stochastic), and degree of complexity (e.g., mechanistic, empirical). Soil survey databases, soil analyses, Soil Data Systems (SDS), and Soil Business Systems (SBS) provide tools and a wide range of quantitative/qualitative data and information to evaluate goods and services for various business applications, but these sources of soil data may be limited in scope due to their static nature. Valuation of soil resources based on soil and non-soil science databases (e.g., National Atmospheric Deposition Program (NADP) databases, etc.) is critically needed to account for these ES/ED as part of business decision-making to provide more sustainable use of soil resources. Since most ecosystems on Earth have been modified by human activity, “soil systems goods and services” (SSGS) may be a more applicable term to describe soil contributions (benefits/damages) to economic activity, compared to a term such as “soil ecosystem goods and services.” arabic 8 English 47
Elena Mikhailova, Christopher Post, Mark Schlautman, Gregory Post, Hamdi Zurqani(7-2020)

This book presents the soil pedodiversity in Libya. Soils are the source of all life; there can be no life without them. Further, each soil has its own history and its present conditions, which have been shaped by many different factors (e.g. climate, biota, parent material, and relief or topography). The book, divided into eight chapters, provides extensive information on Libyan soils. Chapter one provides an introduction and a broad perspective of the subject, while Chapter two covers the history of soil mapping and research in Libya. Chapter three focuses on local factors of soil formation and describes the geology and climate of the region to explain the diversity of its soils. Chapter four discusses soil classification systems and those most commonly used in the country. The fifth chapter illustrates the constraints and limiting factors that negatively affect agricultural activities across the country. The land cover/land use and the vegetation of the country are described in Chapter six. In turn, Chapter seven presents the status quo of soil biology, the corresponding related research activities, and the other biological properties of Libyan soils. The final chapter (Chapter eight) focus on land degradation and desertification in Libya, emphasizing the main causes, impacts of the phenomena, and efforts to combat it. This book demonstrates the problems that the country is currently facing as a result of climate change, soil erosion, salinization, and pollution, and outlines potential remedies to improve local food security. Bringing together the perspectives and expertise of many distinguished scientists from various universities and institutions in and outside of Libya, the book represents a unique and highly valuable resource. arabic 3 English 15
Hamdi Zurqani, Khaled Ben Mohamed, Azzeddin Elhawej, Mukhtar Elaalem, Bashir Nwer, Az Ali, Eman Ferjani, Merfat Ben Mahmoud, Asma Alnajjar(12-2020)

Sodicity and salinity can adversely affect soil structure and are common constraints to plant growth in arid regions. Current remote sensing techniques cannot distinguish between the various classes of salt-affected soils. Field and laboratory measurements of salt-affected soils are time-consuming and expensive. Mapping of the salt-affected soils can be used in soil conservation planning to identify regions with different degrees of limitations. There is a need to use existing field and laboratory measurements to create maps of classes of salt-affected soils. The objectives of this study are to classify salt-affected soils, use existing field data to interpolate and validate geospatial predictions of the classes of salt-affected soils using Geographic Information Systems (GIS), and create maps showing the different classes and distribution of salt-affected soils. The classification framework for salt-affected soils is based on electrical conductivity (ECe), soil pH and the sodium adsorption ratio (SAR), and provides four degrees of limitations to salt-affected soils: slight (normal soils), moderate (saline soils), severe (sodic soils), and extreme (saline-sodic soils). Spatial interpolation of the field data from northwestern Libya was verified by cross-validation, and maps of the salt-affected soils in the region were created. The majority of soils in this region of Libya are normal (slight degree of limitation). Twenty percent of the topsoil is saline-sodic (extreme degree of limitation). Land use recommendations and rehabilitation strategies can be developed from such maps of salt-affected soil classes. The methodology followed in this study can be applied to other arid regions around the world, particularly in developing countries where budgetary constraints limit detailed field and laboratory measurements of sodicity and salinity. arabic 11 English 70
Hamdi Zurqani, Elena Mikhailova, Christopher Post, Mark Schlautman, Julia Sharp(2-2018)

Ecosystem services (ESs) are increasingly being used by many countries around the world as a framework for addressing the United Nations (UN) Sustainable Development Goals (SDGs). This review article of the usability of Libyan soil databases for ESs and SDGs is the first of its kind for North Africa. The objectives of the article are to: describe the available soil resources of Libya in relation to an ES framework; provide examples of the usability of Libyan soil databases for ES applications (eg, provisioning, Healthy Eating Plate), and describe some of the typical disservices in the country. Desertification, salinization, and limited freshwater resources are the largest challenges (disservices) for agriculture and future development in Libya. Seawater intrusion in coastal areas due to rising sea levels has resulted in high concentrations of salts in irrigation waters, which can lead to low soil productivity. These challenges can be addressed by integrating Libyan soil resources into a market that transforms resources into goods and services to meet human demand in a sustainable manner, with non-market institutions mediating the interactions between humans and the environment. If Libyan soil resources are taken into account by both market and non-market institutions, it will lead to more efficient use of soil resources and also should enable the implementation of innovative strategies, such as integrated farming systems, non-soil-based agricultural production (eg, hydroponics), and alternative farming practices. arabic 12 English 68
Hamdi Zurqani, Elena Mikhailova, Christopher Post, Mark Schlautman, Azzeddin Elhawej(5-2019)

Soil salinity is one of the most important issues in arid and semi arid regions, which is directly linked to desertification and land degradation. Several studies related to soil and water salinity assessment, and mapping were conducted in Libya using traditional methods. However, they covered only the time of measurements and did not address the dynamic nature of salinity process. In addition, they lack cost and time effectiveness. Therefore, there is pressing need to use a high tech method that is cost, time and labor effective to assess the change in soil salinity in north- west of Libya. The aim of this paper is to identify the change in saline soils (Sehbkha) using Remote Sensing (RS) and geographic information system (GIS) techniques. Land Sat Satellite images data were acquired for 29 years (1972-1987-2001) to assess the pattern of change. The result revealed that there was a decrease saline soils area ( Sbehbka). Keywords: Libya, GIS, Remote Sensing, Soil, Soil Salinity, Sebkha. arabic 17 English 109
Hamdi Zurqani, Bashir Nwer, Azzeddin Elhawej(12-2012)

Climate variability is considered as the most serious challenge threatens the ecosystem, whether in developing or developed countries. Climate variability affects the agro ecological and growing conditions of crops and livestock that may add significantly to the development challenges of ensuring food security and reducing poverty. In this study, the climate data for the period (1945-2010) was investigated to determine the manifestation of climate variability in the northwest of Libya and its effect on agriculture. The results indicate that the drop in rainfall volumes and irregular distributed over the season and temperature increasing over the study period are the most important consequences of climate variability in Libya, which has a negative influence on the country’s agriculture sector. Time trend of rainfall and temperature were analyzed and the impacts of climate change on agriculture were discussed. Moreover, Pairwise Granger causality test analysis were used to examine the causal relationship between climatic conditions in Libya. The results further indicate that there is an unidirectional relationship existed between changes in temperature and the production of dates and tomatoes, and unidirectional causality runs from rainfall to onion, potatoes olive and ground peanut.
Nagib M. said Froja, Khaled R. Elbeydi(12-2016)

الملخص... لقد تم في هذا البحث اختيار مؤشرات أداء الري الزراعي التي تم تطويرها في المركز العالمي لإدارة مياه الري وتطبيقها على أهم المحاصيل المروية داخل منطقة شمال غرب ليبيا، حسب الممارسات الزراعية السائدة حالياً بين المزارعين وحسب ما يجب أن تكون عليه هذه الممارسات إذا ما أدخلت عليها بعض التحسينات المقترحة من الفريق البحثي القائم بهذه الدراسة، من أهم المؤشرات التي تم اختيارها وتطبيقها في هذه الدراسة مؤشر ”القيمة العيارية الكلية للإنتاج المحصوليStandardized Gross Value of Production))، ومؤشر مخرج وحدة المساحة المروية ومؤشر مخرج وحدة الحجم من إمداد مياه الري، وبمقارنة نتائج مؤشرات الأداء للممارسات الزراعية القائمة حالياً بمؤشرات الأداء التي تم الحصول عليها من نتائج التجارب الحقلية لهذه الدراسة يتضح ارتفاع مخرج وحدة المساحة من 6483 دينار ليبي للهكتار إلى 11605 دينار ليبي للهكتار وارتفاع مخرج وحدة الحجم من إمداد مياه الري من 0.63 دينار للمتر المكعب إلى 1.63 دينار ليبي للمتر المكعب، تبين هذه النتائج أهمية هذه المؤشرات في توضيح التأثيرات الاقتصادية للتدخلات التي يمكن القيام بها لتحسين الممارسات الزراعية والبدائل المحصولية ونظم الإنتاج الزراعي والمفاضلة بينها حسب القيم والعائدات النقدية الممكن الحصول عليها من هذه المؤشرات الكلمات المفتاحية: SGVP، الإنتاجية المائية، العائد الاقتصادي، شمال غرب ليبيا
أحمد إبراهيم محمد خماج, يونس ضو زايد الزليط, مختار محمود مختار العالم(12-2019)