Soil databases are very important for assessing ecosystem services at different administrative levels (e.g., state, region etc.). Soil databases provide information about numerous soil properties, including soil inorganic carbon (SIC), which is a naturally occurring liming material that regulates soil pH and performs other key functions related to all four recognized ecosystem services (e.g., provisioning, regulating, cultural and supporting services). However, the ecosystem services value, or “true value,” of SIC is not recognized in the current land market. In this case, a negative externality arises because SIC with a positive value has zero market price, resulting in the market failure and the inefficient use of land. One potential method to assess the value of SIC is by determining its replacement cost based on the price of commercial limestone that would be required to amend soil. The objective of this study is to assess SIC replacement cost value in the contiguous United States (U.S.) by depth (0–20, 20–100, 100–200 cm) and considering different spatial aggregation levels (i.e., state, region, land resource region (LRR) using the State Soil Geographic (STATSGO) soil database. A replacement cost value of SIC was determined based on an average price of limestone in 2014 ($10.42 per U.S. ton). Within the contiguous U.S., the total replacement cost value of SIC in the upper two meters of soil is between $2.16T (i.e., 2.16 trillion U.S. dollars, where T = trillion = 1012) and $8.97T. States with the highest midpoint total value of SIC were: (1) Texas ($1.84T), (2) New Mexico ($355B, that is, 355 billion U.S. dollars, where B = billion = 109) and (3) Montana ($325B). When normalized by area, the states with the highest midpoint SIC values were: (1) Texas ($2.78 m−2), (2) Utah ($1.72 m−2) and (3) Minnesota ($1.35 m−2). The highest ranked regions for total SIC value were: (1) South Central ($1.95T), (2) West ($1.23T) and (3) Northern Plains ($1.01T), while the highest ranked regions based on area-normalized SIC value were: (1) South Central ($1.80 m−2), (2) Midwest ($0.82 m−2) and (3) West ($0.63 m−2). For land resource regions (LRR), the rankings were: (1) Western Range and Irrigated Region ($1.10T), (2) Central Great Plains Winter Wheat and Range Region ($926B) and (3) Central Feed Grains and Livestock Region ($635B) based on total SIC value, while the LRR rankings based on area-normalized SIC value were: (1) Southwest Plateaus and Plains Range and Cotton Region ($3.33 m−2), (2) Southwestern Prairies Cotton and Forage Region ($2.83 m−2) and (3) Central Great Plains Winter Wheat and Range Region ($1.59 m−2). Most of the SIC is located within the 100–200 cm depth interval with a midpoint replacement cost value of $2.49T and an area-normalized value of $0.34 m−2. Results from this study provide a link between science-based estimates (e.g., soil order) of SIC replacement costs within the administrative boundaries (e.g., state, region etc.). arabic 19 English 114
Garth Groshans, Elena Mikhailova, Christopher Post, Mark Schlautman, Hamdi Zurqani, Lisha Zhang(12-2018)

المستخلص أدى استخدام الميكنة الزراعية إلى التوسع في حراثة الأراضي وحراثتها سنويا في المنطقة الغربية من ليبيا مما أثر في خصوبة التربة وفي قدرتها الإنتاجية ولما للمادة العضوية من أهمية في تحديد إنتاجية الأراضي وخصوبتها لذا يهدف هذا البحث الى تحديد نسبة محتوى المادة العضوية لثلاثة انواع من الترب الليبية الأكثر انتشارا في المنطقة الغربية وقد أسهمت المعلومات الجغرافية والخرائط المختلفة المتوفرة عن المنطقة في سهولة تحديد مواقع تجميع عينات التربة. والتوسع في إجراء البحوث العلمية. أظهر وصف قطاعات التربة إلى تباين في عدد أفاقها ومادة أصلها وتباين في قوامها جمعت عينات التربة وقدر محتواها من المادة العضوية فبينت النتائج انخفاض محتوى عينات أنواع الترب الثلاثة من المادة العضوية كما أن نوعيات الترب الثلاثة لم تتباين في محتواها من المادة العضوية علي الرغم من اختلاف نوعيتها وعملية استغلالها فالترب البنية المحمرة الجافة والترب السيليكاتية تستغل في زراعة المحاصيل والترب الضحلة تستغل كمراعي وغابات وفقر النوعية الأولي والثانية الحاد من المادة العضوية ربما يعود إلى عمليات الحصاد الجائر وإزالة الغطاء النباتي والرعي المكثف للأراضي وكل ذلك يؤدي إلى تعريض التربة إلى حرارة الجو المباشرة صيفا مما يؤدي إلى تفسخها أى فقدها, ويعكس هذا التأثير البيئي الكبير من خلال المناخ والموقع في نمو الغطاء النباتي وتكوين المادة العضوية فعلي الرغم من أنها تنتمي إلي نوعيات أو رتب مختلفة إلا أنه لم يكن بينها اختلاف كبير في خواصها الأساسية ومن أهمها محتواها من المادة العضوية التي يعتمد عليه في تحديد إنتاجية الأراضي وخصوبتها في حين تختلف نوعية أو رتبة التربة الواحدة في المناطق البيئية المختلفة في محتواها من المادة العضوية بشكل كبير. يجب توجيه المزارعين الي أهمية التبوير واستخدام الدورة الزراعية وتوجيهم الي أهمية التسميد الخضري وهي حراثة الأرض في الربيع لخلط الحشائش الخضراء بالتربة فيعمل ذلك علي زيادة محتواها من المادة العضوية وبالتالي علي زيادة خصوبتها من أجل خلق تنمية مستديمة في المنطقة. الكلمات الدالة: المادة العضوية , الترب الليبية , خصوبة التربة
عبدالفتاح فرج أبوفايد, عبدالفتاح فرج أبوفايد(12-2012)

Soil ecosystem services (ES) (e.g., provisioning, regulation/maintenance, and cultural) and ecosystem disservices (ED) are dependent on soil diversity/pedodiversity (variability of soils), which needs to be accounted for in the economic analysis and business decision-making. The concept of pedodiversity (biotic + abiotic) is highly complex and can be broadly interpreted because it is formed from the interaction of atmospheric diversity (abiotic + biotic), biodiversity (biotic), hydrodiversity (abiotic + biotic), and lithodiversity (abiotic) within ecosphere and anthroposphere. Pedodiversity is influenced by intrinsic (within the soil) and extrinsic (outside soil) factors, which are also relevant to ES/ED. Pedodiversity concepts and measures may need to be adapted to the ES framework and business applications. Currently, there are four main approaches to analyze pedodiversity: taxonomic (diversity of soil classes), genetic (diversity of genetic horizons), parametric (diversity of soil properties), and functional (soil behavior under different uses). The objective of this article is to illustrate the application of pedodiversity concepts and measures to value ES/ED with examples based on the contiguous United States (U.S.), its administrative units, and the systems of soil classification (e.g., U.S. Department of Agriculture (USDA) Soil Taxonomy, Soil Survey Geographic (SSURGO) Database). This study is based on a combination of original research and literature review examples. Taxonomic pedodiversity in the contiguous U.S. exhibits high soil diversity, with 11 soil orders, 65 suborders, 317 great groups, 2026 subgroups, and 19,602 series. The ranking of “soil order abundance” (area of each soil order within the U.S.) expressed as the proportion of the total area is: (1) Mollisols (27%), (2) Alfisols (17%), (3) Entisols (14%), (4) Inceptisols and Aridisols (11% each), (5) Spodosols (3%), (6) Vertisols (2%), and (7) Histosols and Andisols (1% each). Taxonomic, genetic, parametric, and functional pedodiversity are an essential context for analyzing, interpreting, and reporting ES/ED within the ES framework. Although each approach can be used separately, three of these approaches (genetic, parametric, and functional) fall within the “umbrella” of taxonomic pedodiversity, which separates soils based on properties important to potential use. Extrinsic factors play a major role in pedodiversity and should be accounted for in ES/ED valuation based on various databases (e.g., National Atmospheric Deposition Program (NADP) databases). Pedodiversity is crucial in identifying soil capacity (pedocapacity) and “hotspots” of ES/ED as part of business decision making to provide more sustainable use of soil resources. Pedodiversity is not a static construct but is highly dynamic, and various human activities (e.g., agriculture, urbanization) can lead to soil degradation and even soil extinction. arabic 7 English 46
Elena A. Mikhailova , Hamdi A. Zurqani , Christopher J. Post , Mark A. Schlautman, Gregory C. Post (3-2021)