The below list represents only planned manuscripts. Some of these
manuscripts have not been received by the Editorial Office yet. Papers
submitted to MDPI journals are subject to peer-review.
Title: Tree Windbreaks for Protection and Restoration of Chernozems in the Russian Steppe
Authors: Yury G. Chendev 1, Thomas J. Sauer 2,*, Guillermo Hernandez Ramirez 3 and C. Lee Burras 4
1Belgorod State University, Belgorod, Russia
2USDA-ARS, National Laboratory for Agriculture and the Environment, Ames, Iowa, USA; E-Mail: email@example.com
3University of Alberta, Edmonton, Alberta Canada
4Iowa State University, Ames, Iowa, USA
Abstract: Afforestation of agricultural lands is a well known and established cropland management practice within the Northern Hemisphere. In the 19th and 20th centuries, this practice was implemented to protect croplands from wind and water erosion, improve microclimates for crop growth, and provide refuge for wild animals and native plants. Recently, tree windbreaks have been recognized as ecosystems for atmospheric carbon sequestration and thus, climate change mitigation. Extensive windbreak planting has occurred on chernozem in the Central Russian Upland (which is situated in the central part of Eastern Europe). This field study was conducted across three climatic gradients, which range from cool and wet in the north to warm and dry in the south. Windbreak age ranged from 55–57 years. At each site, soil pits within the windbreak, adjacent long-term (i.e., >150 year-old) crop fields, and nearby undisturbed grassland were sampled to a depth of 1.5 m. Horizons were delineated, the depths to the carbonates were determined, and soil samples were collected for laboratory analyses. Windbreak soils had consistently thicker, organic carbon-enriched A or A + AB horizons, which were similar to those of undisturbed grassland soils. A strong linear relationship was detected between organic-enriched horizon thickness and the hydrothermal coefficient (HTC). Within the 0–30 cm layer, organic carbon stocks under windbreaks were lower or approximately equal to those in undisturbed grasslands (−33 to 12 Mg ha-1). This reflects soil organic matter loss during cultivation (90–95 years) before windbreak planting; the loss was partially compensated for by organic C accumulation during the 55–57 years following the windbreak’s establishment. Within the 30–100 cm layer, organic C stocks beneath windbreaks were 40 to 52 Mg ha-1 greater than in those of the undisturbed grassland soils. Therefore, the total organic C stocks within the top meter of windbreak soils were greater at all sites than in virgin chernozems. These findings confirm that for the central part of Eastern Europe, tree windbreaks can improve soil quality by enhancing soil organic matter while also providing a sink for atmospheric carbon.
Keywords: soil organic carbon; chernozems; afforestation; soil transformation
Title: Degradation and Health of Western European Soils: Historical, Current and Future Perspectives
Authors: I. Virto, M. J. Imaz, O. Fernández-Ugalde, N. Gartzia-Bengoetxea, A. Enrique and P. Bescansa
Abstract: Historical land use in Western Europe, as in agrarian societies elsewhere, did not consider soil sustainability, and thus resulted in degradation in many areas. Soil degradation has accelerated in recent decades due to increasing demands from nearly all economic sectors (agriculture, households, industries, transportation, and tourism). In many cases, inappropriate land management practices, land-use changes, policy changes or inadequate protection of soil resources contributed to the degradation. These changes, coupled with more extreme climatic patterns, are threatening the health/quality of soils in Western Europe. In this work, we review the major problems contributing to soil degradation (chemical, physical, and biological degradation, and soil loss), and their importance in different regions of Western Europe. Emphasis is given to the degradation threat associated with agriculture and forestry. The diversity of soil types, topographies, and climatic zones across Europe, as well as the regional diversity in social and economic drivers, are also examined. We then evaluate the most widespread and available soil, crop, and forest management strategies being applied across Europe to mitigate soil degradation problems. This includes improved fertilization strategies, conservation agriculture, regenerative farming, water management (irrigation and water harvesting) sustainable forest management, agroforestry, agroecology, and afforestation of degraded land and other political solutions, such as land abandonment and soil protection legislation. Factors influencing the successes and failures of these strategies in different areas of Western Europe are examined. Finally, we examine various perspectives, such as soil quality monitoring, strategies for sustainable development, quantification of ecosystem services, and roles for the European Agricultural Police (CAP) in reversing and preventing soil degradation and enhancing soil health in Western Europe. This includes evaluating trade-offs between climate change mitigation and soil quality enhancement, optimization of nutrient cycling in agricultural and forest systems, soil erosion control, improved irrigation, biochar amendments, and other strategies. We conclude that sustainable land-management can have a central role in preventing soil degradation, but an increasing global population, demand for wood and fiber sources, expanded global markets, and Europe’s 2020 growth strategy are all factors increasing the pressure on terrestrial ecosystems in Western Europe.
Title: Soil Degradation: A North American Perspective
Authors: R.Louis Baumhardt, Bobby A. Stewart and Humberto Blanco-Canqui
Abstract: Soil can be degraded through erosion, chemical contamination, and/or formation of undesirable physical, chemical, or biological properties through industrialization, overgrazing, or use of inappropriate farming practices at rates superseding natural capacities for recuperation or regeneration. The often overlooked and practically irreversible effects of urban sprawl should also be included; nevertheless, soil degradation reflects unsustainable soil resource management that is global in scope and compromises world food security. In North America, soil degradation preceded the catastrophic wind erosion associated with the dust bowl during the 1930’s, but that event provided the impetus for improving management of soils degraded by both wind and water erosion. Congressional mandates protecting water quality may have similarly contributed to ameliorating site-specific chemical soil degradation following contamination from industrial processing or exposure to mine spoils; however, sustained investigations have been directed toward understanding broader aspects of chemical degradation by relating farm nutrient management to contamination of surface and subsurface drainage water. Remediation or prevention of soil degradation requires integrated management solutions. To illustrate such strategies, we present experimental results using crop residue management to intercept raindrop impact and maintain higher infiltration rates that increase soil water storage and crop biomass production. Increased biomass, potentially, increases organic carbon and stable aggregates that control wind or water erosion. A current soil degradation topic reflects the integrated impact of inappropriate or excessive harvest of crop residues as biofuel feedstock or excessive grazing which can increase soil compaction, decrease subsequent rain or irrigation water infiltration and thus limit the amount of plant-available water needed for sustainable crop production. Such degradation further depresses biomass yield, which limits the regenerative benefits of soil organic matter and may require innovative management practices, such as the use of cover crops.
Title: Threats to Sustainability of Soil Functions in Central and Southeast Europe
Author: Hikmet Gunal 1,*, Tayfun Korucu 2, Martha Birkas 3 and Engin Ozgoz 1
1Gaziosmanpasa University, Tokat Turkey,
2Kahramanmaraş Sutcu Imam University, Tokat Turkey
3Institute of Crop Production, Szent István University, H-2103 Gödöllo, Hungary
Abstract: A diverse topography, along with deforestation, changing climatic conditions, long-term human settlement, overuse of agricultural lands without sustainable planning, and cultural difficulties in accepting conservative management practices have increased the vulnerability of many soils to degradation and resulted in a serious decline in their functional capacity. A progressive reduction in the capacity of soils to support plant productivity is not only a threat in the African continent and its large desert zone, but also a threat and real concern for future generations in several parts of Central and Southeastern Europe (CASEE). The loss of soil functions throughout CASEE is mainly related to the human activities that have profound influence on soil dynamic characteristics. Improper management of soils has made them more vulnerable to degradation through water and wind erosion, organic matter depletion, salinity, acidification, crusting and sealing, and compaction. The steady extension of degradation has substantial implications for the long-term sustainability of the soils' capability to support human communities and to resist desertification. As an example, use of excessive irrigation and the lack of appropriate drainage in one of the worlds' largest irrigation projects (called the "south eastern irrigation project") resulted in severe salinity problems and productivity loss in semi-arid regions of Turkey. Heavy equipment and crop rotations unsuitable for the soil characteristics, topographies, and climatic conditions resulted in water and wind erosion as being the main land-degrading factor in Turkey. According to reports from the Ministry of Water and Forest Affairs, 59% of arable land and 64% of the rangelands have severe erosion problems in Turkey. The decline in soil quality is continuing and will probably accelerate if sustainable agricultural and land management practices are not identified, thoroughly understood, and implemented. The lack of uniform criteria for the assessment and evaluation of soil quality in CASEE prevents scientific assessments for determining whether existing management practices are leading to soil quality improvement, or if not, what “best management” practices should be recommended to mitigate and revere the loss of soil health.
Keywords: Soil health, degradation, land management, erosion, Central and Southeast Europe
Title: Understanding and Enhancing Soil Health: The Solution for Reversing Soil Degradation
Author: Mike Lehman
Affiliation: USDA-ARS, National Laboratory for Agriculture and the Environment, Ames, Iowa, USA; E-Mail: firstname.lastname@example.org
Abstract: This special issue of Sustainability documents both the magnitude and global prevalence of soil degradation and helps illustrate (1) various factors contributing to the problem, (2) its past and current impacts, and (3) projected consequences to humankind if degradation of our fragile soil resources is not reversed before our global population grows beyond 9.5 Billion. Our objective is to provide an optimistic strategy for reversing soil degradation by increasing public and private research efforts on the concept of soil health. We begin by defining soil quality/soil health (which we consider to be interchangeable terms), characterizing healthy soil resources, and relating the significance of soil health to agroecosystems and their functions. We examine how soil biology influences soil health and how biological properties and processes contribute to sustainability of agriculture and ecosystem services. We continue by examining what can be done to manipulate soil biology to: (i) increase nutrient availability for production of high yielding, high quality crops, (ii) protect crops from pests, pathogens, weeds, and (iii) manage other factors limiting production and ecosystem services. Next we look to the future by asking what needs to be known about soil biology that is not currently recognized or fully understood. This includes making projections regarding which of the unknown factors could be addressed using current research tools and what types of new expertise will be needed to successfully address other issues. We conclude, based on our perceptions of how new knowledge regarding soil biology will help make agriculture more sustainable and productive, by recommending which of the unknown biological properties and processes should receive first priority through enhanced public and private research in order to reverse the trajectory toward global soil degradation.
Title: Breaking the Cycle of Soil Degradation in Africa
Authors: Katherine L. Tully 1 and Pedro A. Sanchez 2
Affiliation: 1 University of Maryland; Department of Plant Science and Landscape Architecture; College Park, MD 20742, USA
2 Earth Institute at Columbia University; Agriculture and Food Security Center; Palisades, NY 10964, USA
Abstract: Soil degradation is inextricably linked to poverty, and nowhere in the world is this relationship more persistent and pervasive than in Africa. Sixty percent of Africa’s rapidly growing population still relies on agriculture for their livelihoods and 23% of the entire population remains chronically malnourished. African soils where smallholders farmers are located are, in general, not inherently nutrient poor, but are degraded now primarily because of nutrient depletion. Extreme nutrient depletion and overgrazing means that soils are often left bare, which can result in severe soil erosion. In this review, we will discuss the primary causes and current state of soil degradation in Africa, and present several strategies for reversing it. Human wellbeing and environmental health in Africa depend on reversing soil degradation on a landscape dominated by smallholder farms. Of particular importance is improving nutrient management on farms where centuries of nutrient removal through crop harvest and erosion have not been balanced by replenishment through either fertilizers or manure. Estimates suggest that annual nutrient losses (in nitrogen, phosphorus, and potassium) are equivalent to USD 4 billion per year over the past 30 years in 37 African countries. Nevertheless, mineral fertilizers are not the only way to replenish soil nutrients. For example, the planting of leguminous tree species that can fix atmospheric nitrogen can also provide nutrients to soils and crops. Legume tree intercropping systems have been successfully developed in many parts of rural Africa, creating a system that not only enhances crop yields but also provides fuel wood, but they are not widely adopted. They require incentives (subsidies, etc.), but may provide a win–win strategy for reducing pressure on residual forested lands. Due to combined international efforts and national action plans, millions of hectares of cropland are being regenerated through agroforestry, soil conservation, and water management practices on smallholder farms across the Sahel region and elsewhere. Africa poses the current challenge of simultaneously increasing food production and food security, while minimizing environmental costs and the core of finding a solution lies in reversing soil degradation. We will untangle some of these complex relationships in this review and provide potential solutions for simultaneously improving crop yields and soil health.
Title: Overcoming Soil Degradation in India (From India Perspective)
Authors: Ranjan Bhattacharyya, B. Mandal, Ch Srinivasa Rao, B.N. Ghosh, K. Das, D. Sarkar, K.S. Anil and Alan J. Franzluebbers
Abstract: Soil degradation in India is estimated to occur on 147 Mha of land, including 94 Mha from water erosion, 16 Mha from acidification, 14 Mha from flooding, 9 Mha from wind erosion, 6 Mha from salinity, and 7 Mha from a combination of factors. India supports 18% of the world’s human population and 15% of the world’s livestock population, but has only 2.4% of the world’s land area. Despite its low proportional land area, India ranks second worldwide in farm output. Agriculture, forestry, and fisheries account for 17% of the gross domestic product and about 50% of the total workforce of the country. Causes of soil degradation are both natural and human induced. Natural causes include earthquakes, tsunamis, droughts, avalanches, landslides, volcanic eruptions, floods, tornadoes, and wildfires. Human-induced soil degradation results from land clearing and deforestation, inappropriate agricultural practices, improper management of industrial effluents and wastes, over-grazing, careless management of forests, surface mining, urban sprawl, and commercial/industrial development. Inappropriate agricultural practices include repeated tillage and use of heavy machinery, excessive and unbalanced use of inorganic fertilizer materials, poor irrigation and water management techniques, pesticide overuse, inadequate crop residue and/or organic carbon inputs, and poor crop cycle planning. Some underlying social causes of soil degradation in India are land shortage, decline in per capita land availability, economic pressure on land, land tenancy, poverty, and population increase. In this review of India, we intend to (1) describe the main causes of soil degradation in different agro-climatic regions, (2) describe the research results documenting both soil degradation and soil health improvement in various agricultural systems, and (3) offer solutions to improve soil health in different regions using a variety of conservation agricultural approaches.
Title: Soil Quality Indices for Evaluating Smallholder Agricultural Land Uses in Northern Ethiopia
Authors: Aweke M. Gelaw 1,*, B. R. Singh 1 and R. Lal 2,†
1 Norwegian University of Life Sciences, P.O. Box: 5003, 1432 Ås, Norway;
E-mail: email@example.com or firstname.lastname@example.org; Tel.: +47-944-28655; Fax: +47-649-65601
2 Carbon Sequestration and Management Center, The Ohio State University, Columbus, OH 43210, USA
† Current address: Norwegian University of Life Sciences, P.O. Box: 5003, 1432 Ås, Norway
Abstract: Population growth and increasing resource demands in Ethiopia are stressing and degrading agricultural landscapes. Most Ethiopian soils are already exhausted by several decades of over exploitation and mismanagement. Since many agricultural sustainability issues are related to soil quality, its assessment is very important. We determined integrated soil quality indices (SQI) within the surface 0–15 cm depth increment for three agricultural land uses: rain fed cultivation (RF), agroforestry (AF) and irrigated crop production (IR). Each land use was replicated five times within a semi-arid watershed in eastern Tigray, Northern Ethiopia. Using the framework suggested by Karlen and Stott (1994), four soil functions regarding soil’s ability to: (1) accommodate water entry (WE), (2) facilitate water movement and availability (WMA), (3) resist degradation (RD), and (4) supply nutrients for plant growth (PNS) were estimated for each land use. Accordingly, AF land use had significantly higher values (p < 0.05) than RF for all soil functions except for RD. Finally, the four soil quality functions were integrated into an overall SQI, and the values for the three land uses were in the order: 0.58 (AF) > 0.51 (IR) > 0.47 (RF). Thus, AF scored significantly higher SQI (p < 0.01) than that of RF. The dominant soil properties influencing the integrated SQI values were soil organic carbon (26.4%), water stable aggregation (20.0%), total porosity (16.0%), total nitrogen (11.2%), microbial biomass carbon (6.4%) and cation exchange capacity (6.4%). Collectively, those six indicators accounted for more than 80% of the overall SQI values.
Keywords: soil quality; soil functions; land degradation; land use; Ethiopia
Title: Strategies for Mitigating Wind Erosion Induced Soil Degradation in Northern China
Authors: Zhongling Guo, Ning Huang, Zhibao Dong, R. Scott Van Pelt and Ted M. Zobeck
Abstract: Soil degradation is one of the most serious ecological problems in the world. In China, the most common and serious form of soil degradation is soil erosion caused by wind or water. For arid and semi-arid northern China, soil degradation predominantly arises from wind erosion. Trends in soil degradation caused by wind erosion in the northern China frequently change with human activities and climatic change. Fine material emissions caused by wind erosion leads to on-site soil degradation and off-site environmental pollution. To decrease soil loss by wind erosion and enhance local ecosystems, the Chinese government has been encouraging residents to reduce wind-induced soil degradation through several famous projects. These include the “Three Norths” (northwestern, northern, and northeastern parts of China) Shelter Forest System, the Beijing-Tianjin Sand Source Control Engineering Project, and the Grain for Green Project. All these have were implemented a number of decades ago, and have thus created many land management practices across different landscapes. These practices include conservation tillage, water-saving irrigation, windbreaks, afforestation of arable land, and restoration of grasslands. As a result, the aeolian degraded land has been controlled in several regions of the arid and semiarid northern China. However, the challenge of mitigating and further reversing soil degradation caused by wind erosion still remains for this region. In this paper, we will focus on (1) historical and current trends of wind-induced soil degradation in northern China, (2) the status of regions suffering from aeolian soil degradation, (3) current land management practices and problems to combat aeolian soil degradation, and (4) perspectives on reversing wind-induced soil degradation.
Title: Do Current Policies Support Soil Functions? An Analysis for Europe
Authors: Nadia Glæsner 1, Katharina Helming 1and Wim de Vries 2
Affiliation:1 Leibniz Centre for Agricultural Landscape Research (ZALF), DE 2 Alterra, NL
Abstract: No legislation currently exists at the European level focusing exclusively on soil conservation. A cross-policy analysis was carried out to identify gaps and overlaps in existing EU legislation related to soil threats and functions. We found that three soil threats—compaction, salinization and soil sealing—were not addressed in any of the 19 legislative policies that were analyzed. Other soil threats: erosion, organic matter decline, biodiversity decline and contamination, were addressed in existing legislation, but only a few directives provided clear targets to reduce the soil threats. For seven soil functions analyzed, existing legislation address prevention of reducing all soil functions, but very few directives exist to improve soil functionality. Soil degradation is a major problem in Europe which questions whether the existing legislation is sufficient for maintaining soil resources. Addressing individual soil functions in various directives fails to account for the multifunctionality of soils. This paper suggests that a European level legislation would give the EU an added value to ensure soil functionality in support of solving grand societal challenges.