281-300 of 333 Results

Article

Subsurface (Tile) Agricultural Drainage  

Gary R. Sands, Srinivasulu Ale, Laura E. Christianson, and Nathan Utt

Agricultural (tile) drainage enables agricultural production on millions of hectares of arable lands worldwide. Lands where drainage or irrigation (and sometimes both) are implemented, generate a disproportionately large share of global agricultural production compared to dry land or rain-fed agricultural lands and thus, these water management tools are vital for meeting the food demands of today and the future. Future food demands will likely require irrigation and drainage to be practiced on an even greater share of the world’s agricultural lands. The practice of agricultural drainage finds its roots in ancient societies and has evolved greatly to incorporate modern technologies and materials, including the modern drainage plow, plastic drainage pipe and tubing, laser and GPS-guided installation equipment, and computer-aided design tools. Although drainage brings important agricultural production and environmental benefits to poorly drained and salt-affected arable lands, it can also give rise to the transport of nutrients and other constituents to downstream waters. Other unwanted ecological and hydrologic environmental effects may also be associated with the practice. The goal of this article is to familiarize the reader with the practice of subsurface agricultural drainage, the history and extent of its application, and the benefits commonly associated with it. In addition, environmental effects associated with subsurface drainage including hydrologic and water quality effects are presented, and conservation practices for mitigating these unwanted effects are described. These conservation practices are categorized by whether they are implemented in-field (such as controlled drainage) versus edge-of-field (such as bioreactors). The literature cited and reviewed herein is not meant to be exhaustive, but seminal and key literary works are identified where possible.

Article

Surface Irrigation  

Luis S. Pereira and José M. Gonçalves

Surface irrigation is the oldest and most widely used irrigation method, more than 83% of the world’s irrigated area. It comprises traditional systems, developed over millennia, and modern systems with mechanized and often automated water application and adopting precise land-leveling. It adapts well to non-sloping conditions, low to medium soil infiltration characteristics, most crops, and crop mechanization as well as environmental conditions. Modern methods provide for water and energy saving, control of environmental impacts, labor saving, and cropping economic success, thus for competing with pressurized irrigation methods. Surface irrigation refers to a variety of gravity application of the irrigation water, which infiltrates into the soil while flowing over the field surface. The ways and timings of how water flows over the field and infiltrates the soil determine the irrigation phases—advance, maintenance or ponding, depletion, and recession—which vary with the irrigation method, namely paddy basin, leveled basin, border and furrow irrigation, generally used for field crops, and wild flooding and water spreading from contour ditches, used for pasture lands. System performance is commonly assessed using the distribution uniformity indicator, while management performance is assessed with the application efficiency or the beneficial water use fraction. The factors influencing system performance are multiple and interacting—inflow rate, field length and shape, soil hydraulics roughness, field slope, soil infiltration rate, and cutoff time—while management performance, in addition to these factors, depends upon the soil water deficit at time of irrigation, thus on the way farmers are able to manage irrigation. The process of surface irrigation is complex to describe because it combines surface flow with infiltration into the soil profile. Numerous mathematical computer models have therefore been developed for its simulation, aimed at both design adopting a target performance and field evaluation of actual performance. The use of models in design allows taking into consideration the factors referred to before and, when adopting any type of decision support system or multicriteria analysis, also taking into consideration economic and environmental constraints and issues. There are various aspects favoring and limiting the adoption of surface irrigation. Favorable aspects include the simplicity of its adoption at farm in flat lands with low infiltration rates, namely when water conveyance and distribution are performed with canal and/or low-pressure pipe systems, low capital investment, and low energy consumption. Most significant limitations include high soil infiltration and high variability of infiltration throughout the field, land leveling requirements, need for control of a constant inflow rate, difficulties in matching irrigation time duration with soil water deficit at time of irrigation, and difficult access to equipment for mechanized and automated water application and distribution. The modernization of surface irrigation systems and design models, as well as models and tools usable to support surface irrigation management, have significantly impacted water use and productivity, and thus competitiveness of surface irrigation.

Article

Sustainable Coffee Production  

Sarada Krishnan

Coffee is an extremely important agricultural commodity, produced in about 80 tropical countries, with an estimated 125 million people depending on it for their livelihoods in Latin America, Africa, and Asia, with an annual production of about nine million tons of green beans. Consisting of at least 125 species, the genus Coffea L. (Rubiaceae, Ixoroideae, Coffeeae) is distributed in Africa, Madagascar, the Comoros Islands, the Mascarene Islands (La Réunion and Mauritius), tropical Asia, and Australia. Two species are economically important for the production of the beverage coffee, C. arabica L. (Arabica coffee) and C. canephora A. Froehner (robusta coffee). Higher beverage quality is associated with C. arabica. Coffea arabica is a self-fertile tetraploid, which has resulted in very low genetic diversity of this significant crop. Coffee genetic resources are being lost at a rapid pace due to varied threats, such as human population pressures, leading to conversion of land to agriculture, deforestation, and land degradation; low coffee prices, leading to abandoning of coffee trees in forests and gardens and shifting of cultivation to other more remunerative crops; and climate change, leading to increased incidence of pests and diseases, higher incidence of drought, and unpredictable rainfall patterns. All these factors threaten livelihoods in many coffee-growing countries. The economics of coffee production has changed in recent years, with prices on the international market declining and the cost of inputs increasing. At the same time, the demand for specialty coffee is at an all-time high. In order to make coffee production sustainable, attention should be paid to improving the quality of coffee by engaging in sustainable, environmentally friendly cultivation practices, which ultimately can claim higher net returns.

Article

Sustainable Management of Groundwater  

Stephen Foster and John Chilton

This chapter first provides a concise account of the basic principles and concepts underlying scientific groundwater management, and it then both summarises the policy approach to developing an adaptive scheme of management and protection for groundwater resources that is appropriately integrated across relevant sectors and assesses the governance needs, roles and planning requirements to implement the selected policy approach.

Article

Temperate Forest Economics  

Roger Sedjo

The world’s forest cover is approximately 4 billion hectares (10 billion acres). Of this total, approximately one-half is temperate forests. These range from the subtropics to roughly 65 degrees in latitude. As we move toward the equator, the forests would generally be considered tropical or subtropical, while forest above the 65th latitude might be considered boreal. Only a relatively small fraction of the forests that are temperate are managed in any significant manner. The major types of management can vary from serious forest protection to selective harvesting, with considerations for regeneration. Intensive forestry exists in the form of plantation forestry and is similar to agricultural cropping. Seedlings are planted, and the trees are managed in various ways while growing (e.g. fertilizers, herbicides, thinnings) and then harvested at a mature age. Typically, the cycle of planting and management then begins anew. Approximately 200 million hectares of forests are managed beyond simply minimal protection and natural regeneration. Recent estimates suggest that over 100 million hectares globally are intensively managed planted forests. The largest representatives of these forests are found in the Northern Hemisphere (e.g., the United States), China, and various countries of Europe, especially the Nordic countries. However, Brazil, Chile, New Zealand, and Australia are important producers while being in the Southern Hemisphere. A high percentage of managed forests are designed to produce industrial wood for construction and for pulp and paper production. Finally, in some countries like China, planted forests are intended to replace forests destroyed decades and even centuries ago. Many of these planted forests are intended to provide environmental services, including water capture and control, erosion control and soil protection, flood control, and habitat for wild life. Recently, forests are being considered as a vehicle to help control global warming. In addition, afforestation and/or reforestation may help address damages after a disturbance such as a fire. In China, the “green wall” has been established to prevent shoreline erosion in major coastal areas.

Article

Terracing: From Agriculture to Multiple Ecosystem Services  

Paolo Socci, Alessandro Errico, Giulio Castelli, Daniele Penna, and Federico Preti

Agricultural terraces are widely spread all over the world and are among the most evident landscape signatures of the human fingerprint, in many cases dating back to several centuries. Agricultural terraces create complex anthropogenic landscapes traditionally built to obtain land for cultivation in steep terrains, typically prone to runoff production and soil erosion, and thus hardly suitable for rain-fed farming practices. In addition to acquiring new land for cultivation, terracing can provide a wide array of ecosystem services, including runoff reduction, water conservation, erosion control, soil conservation and increase of soil quality, carbon sequestration, enhancement of biodiversity, enhancement of soil fertility and land productivity, increase of crop yield and food security, development of aesthetic landscapes and recreational options. Moreover, some terraced areas in the world can be considered as a cultural and historical heritage that increases the asset of the local landscape. Terraced slopes may be prone to failure and degradation issues, such as localized erosion, wall or riser collapse, piping, and landsliding, mainly related to runoff concentration processes. Degradation phenomena, which are exacerbated by progressive land abandonment, reduce the efficiency of benefits provided by terraces. Therefore, understanding the physical processes occurring in terraced slopes is essential to find the most effective maintenance criteria necessary to accurately and adequately preserve agricultural terraces worldwide.

Article

The Basic Systems of Surface Water Allocation  

Joseph W. Dellapenna

From earliest times, at least in arid and semi-arid regions, law has been used to allocate water to particular users, at particular locations, and for particular uses, as well as to regulate the uses of water. In the early 21st century, such laws are found everywhere in the world. While the details of such systems of water law are specific to each culture, these systems, in general terms, conform to one of three basic patterns, or to some combination thereof. The three patterns can be understood as a system of common property, a system of private property, or a system of public property. In a common property system, each person is free to use water as he or she chooses so long as the person has lawful access to the water source and does not unreasonably interfere with other lawful users. Such systems were common in humid regions where generally there was enough water available for all uses, but these break down when demand begins to outstrip supply frequently. Private property systems, more common in arid and semi-arid regions, where water is generally not available to meet all demand on the water sources, is a system that allocates specific amounts of water from an identified water source, for a particular water use at a particular location, and with a definite priority relative to other uses. The problem with such private property systems is their rigidity, with transfers of existing water allocations to new uses or new locations proving difficult in practice. In Australia, the specified claim on a water source is defined not as a quantity, but as a percentage of the available flow. Despite the praise heaped upon this system, it has proven difficult to implement without heavy government intervention, benefiting only large irrigators without adequately addressing the public values that water sources must serve. In part, the problems arise because cheating is easier in the absence of clear volumetric entitlements. The public property systems, which has roots dating back centuries but is largely an artifact of the 20th century, treats water as subject to active public management, whether through collaborative decision-making by stakeholders (a situation that is also sometimes called “common property” but is actually very different from the concept of common property used here), or through governmental institutions. Public property systems seek to avoid the deficiencies of the other two systems (particularly by avoiding the incessant conflicts characteristic of common property systems as demand approaches supply and the rigidity characteristics of actual private property systems), but at the cost of introducing bureaucratized decision making. In the late 20th century, many stakeholders, governments, and international institutions turned to market systems—usually linked to a revived or new private property system—as the supposed optimum means to allocate and re-allocate water to particular uses, users, and locations. Before the late 20th century, markets were rare and small, but institutions like the World Bank set about to make them the primary mechanism for water allocation. Markets, however, proved difficult to implement, at least without transferring wealth from relatively poor users to more prosperous users, and therefore produced a backlash in the form of support for a human right to water that would trump the private property claims central to water markets. The protection of public values, such as ecological or navigational flows, also proved difficult to maintain in the face of the demands of the marketplace. Each of these systems has proven useful in particular settings, but none of them can be universally applied.

Article

The Economic and Health Impacts of Inadequate Sanitation  

Luis Andrés, George Joseph, and Suneira Rana

Nearly half of the world’s population, 4.2 billion people, lack access to a hygienic sanitation facility. About 673 million people regularly defecate outdoors, in the open. Many of those who still lack access to sanitation services are among the most challenging populations to reach: the poorest, the most remote, and the most marginalized. Inadequate sanitation is also a major cause of death and disease in countries around the world, causing 432,000 diarrheal deaths annually and contributing to several neglected tropical diseases, including intestinal worm infections, schistosomiasis, and trachoma. It also contributes to malnutrition, adversely affecting early childhood development and thus affecting long-term outcomes, such as educational attainment and earnings in later life. The disease burden of inadequate sanitation overwhelmingly falls on the poor. Sanitation infrastructure access can result in direct benefits that households receive when they have access to sanitation services and an external benefit or externality produced by a community’s access to clean sanitation infrastructure. Thus, for the full benefits of sanitation infrastructure to be realized, efforts should focus on improving community-wide coverage of improved sanitation and eliminating open defecation. This expands the menu of policy options available for targeting conditions like anemia and undernutrition and would require a significant shift in thinking for many researchers and policymakers, who tend to overlook the important role of disease in determining “nutritional” outcomes. Beyond their intrinsic value to human health and well-being, improved sanitation services would play a contributory and catalytic role in furthering progress toward other development goals, particularly those relating to education, and sustainable economic growth. Thus, furthering people’s access to adequate sanitation services is a necessary milestone in the global stride toward a sustainable, high quality of life for all.

Article

The Economics of Marine Plastic Pollution  

Clemens W. Gattringer

Ubiquitous marine plastic pollution has become a prominent ecological issue, as it provokes implications that threaten marine species, induces health concerns, and causes vast economic damages. The complex dynamics behind its pervasive occurrence are multipronged and multidimensional, and simple clear-cut causal chains cannot always be identified. Analytical appraisals aiming to advance the understanding of pervasive plastic pollution need to address these complexities and acknowledge the interconnectedness of social and ecological systems. Orthodox economic analyses have insufficiently addressed this integration and are frequently characterized by shallow transdisciplinary and monodisciplinary approaches. As a result, several mechanisms that are highly relevant in constituting the problem tend to be neglected by presuming simplistic assumptions about human agency and inadequate nature-economy relationships. This reductionism in the conceptualization is mirrored in the policy responses that are advocated to address the issue. A broader perspective and the integration of different disciplinary concepts (such as biophysical limits as a result of the laws of thermodynamics, the notion of power, cognitive biases, institutions, and incommensurability) can underpin a more holistic perspective that considers the issue’s inherent complexities. While in a market idealist world consumers can “vote with their wallets” and transcend their values into purchasing decisions on the market, in reality there are essential difficulties to such an approach. Marine plastic pollution thus challenges economic thinking to address this real-world ecological challenge with insights that are compatible with and noncontradictory to the broad body of knowledge already elaborated by natural sciences. These perspectives are essential not only for forming a substantive interdisciplinary analysis and understanding the underlying institutions of consumption and production, clear key drivers of the problem, but also to identify promising political solutions for meaningful change.

Article

The Economics of Marine Reserves  

Venetia Alexa Hargreaves-Allen

Marine protected areas (MPAs) remain one of the principal strategies for marine conservation globally. MPAs are highly heterogeneous in terms of physical features such as size and shape, habitats included, management bodies undertaking management, goals, level of funding, and extent of enforcement. Economic research related to MPAs initially measured financial, gross, and net values generated by the habitats, most commonly fisheries, tourism, coastal protection, and non-use values. Bioeconomic modeling also generated important insights into the complexities of fisheries-related outcomes at MPAs. MPAs require a significant investment in public funds for design, designation, and ongoing management, which have associated opportunity costs. Therefore cost-benefit analysis has been increasingly required to justify this investment and demonstrate their benefits over time. The true economic value of MPAs is the value of protection, not the resource being protected. There is substantial evidence that MPAs should increase recreational values due to improvements in biodiversity and habitat quality, but assumptions that MPAs will generate such improvements may not be justified. Indeed, there remains no equivocal demonstration of spillover in fisheries adjacent to MPAs, due in part to the variability inherent in ecological and socio-economic processes and limited evidence of tourism benefits that are biologically or socio-cultural sustainable. There is a need for carefully designed valuation studies that compare values for areas within MPAs compared the same areas without management (the counterfactual scenario). The ecosystem service framework has become widely adopted as a way of characterizing goods and services that contribute directly or indirectly to human welfare. Quantitative analyses of the marginal changes to ecosystem services due to MPAs remains rare due to the requirements of large amounts of fine-grained data, relatively undeveloped bio-physical models for the majority of services, and the complexities of incorporating ecological nonlinearities and threshold effects. In addition while some services are synergistic (so that double counting is difficult to avoid), others are traded off. Such marginal ecosystem service values are highly context specific, which limits the accuracy associated with benefits transfer. A number of studies published since 2000 have made advances in this area, and this is a rapidly developing field of research. While MPAs have been promoted as a sustainable development tool, there is evidence of significant distributive impacts of MPAs over time, over different time scales and between different stakeholders, including unintended costs to local stakeholders. Research suggests that support and compliance is predicated on the costs and benefits generated locally, which is a major determinant of MPA performance. Better understanding of socio-economic impacts will help to align incentives with MPA objectives. Further research is needed to value supporting and regulating services and to elucidate how ecosystem service provision is affected by MPAs in different conditions and contexts, over time and compared to unmanaged areas, to guide adaptive management.

Article

The Emerging Environmental Economic Implications of the Urban Water–Energy–Food (WEF) Nexus: Water Reclamation with Resource Recovery in China, India, and Europe  

Daphne Gondhalekar, Hong-Ying Hu, Zhuo Chen, Shresth Tayal, Maksud Bekchanov, Johannes Sauer, Maria Vrachioli, Mohammed Al-Azzawi, Hannah Patalong, Hans-Dietrich Uhl, Martin Grambow, and Jörg E. Drewes

With economic and population growth, industrialization, urbanization, and globalization, demand for natural resources such as water, energy, and food continues to increase, particularly in cities. Overconsumption of resources has led to degradation of the environment, a process that is interacting with and is further accelerated by a dangerous alteration to the climate. Fast growing cities worldwide already face severe technical difficulties in providing adequate infrastructure and basic services in terms of water and energy. This situation is set to become increasingly difficult with climate change impacts. The latter are increasingly affecting economically developing as well as developed countries. However, cities often have limited capacities to take comprehensive climate action. Hence, practicable, scalable, and adaptable solutions that can systematically target key entry points in cities are needed. The Water-Energy-Food (WEF) Nexus concept is one potential integrated urban planning approach offering cities a more sustainable development pathway. Within this concept, urban water reclamation with resource recovery offers a key potential: reclaimed products such as water, bioenergy, nutrients, and others are valuable resources for which markets are emerging. Reclaiming water can also reduce stress on natural resources and support the prevention of environmental pollution. Thus, it can support water, energy, and food security and the achievement of the United Nations Sustainable Development Goals. However, so far there are few implemented examples of urban water reclamation with resource recovery at urban scales. Examples of good practice in cities in China, India, and Europe highlight key enablers and barriers to the operationalization of water reclamation with resource recovery and implications in terms of environmental economics relevant for cities worldwide. These findings can support a systemic sociotechnical transition to a circular economy.

Article

The Neoclassical Decision-Making Paradigm and Environmental Valuation: An Environmental Ethics Perspective  

Gregory Cooper

The relationship between environmental ethics and the application of economic values to the environment has followed two main paths: (1) blocking attempts to value the environment economically by extending the concept of moral standing to elements of the natural world, and (2) attempting a pragmatic reconciliation that harnesses the efficacy of economic motivation while avoiding the excesses of an exclusively economic perspective. The pragmatic reconciliation must still come to grips with several ethical issues that confront environmental valuation. The fact that economics is grounded in a utilitarian consequentialism renders it susceptible to some long-standing deontological challenges having to do with rights and justice. Other challenges include a reluctance to embrace value pluralism, overly ambitious attempts at pricing, failure to incorporate deeper value commitments that do not take the form of preferences, and the inadequacies of a preference-satisfaction account of well-being.

Article

The Problem of Water Markets  

Michael Hanemann

Water marketing and property right reform are intertwined. Water markets are advocated as a solution for water scarcity, but changes in water rights are often required if the scope of water marketing is to expand. This is true in many countries, including (but not limited to) the United States and Australia. The focus here is on the United States. So far, water marketing in the Western United States is not producing long-run reallocation on the scale expected. The chief impediment is the complexities in existing water rights. An important distinction is between a property right to extract water and put it to use versus a contractual right to receive water from a supply organization. In the United States, the property right to water is a unique form of property. Unlike land, it is a right of use, not ownership; the quantity afforded by the right is incompletely specified; and the ability to transfer it is constrained by the obligation to avoid harm through the externality of return flows and also by unreliable historical records of rights. These constraints are often relaxed for short-term transfers (leases) of a property right lasting only a year or two. Also, these constraints generally do not apply to a contract right to receive water. Thus, most of the surface water transferred in the United States is either contract water moving within supply system boundaries or short-term leases of appropriative rights. These transfers tend to provide short-run flexibility for water users rather than long-run reallocation. For more significant long-run reallocation of water, some modification of the property right to water is essential. Devising a politically acceptable way to make the needed changes is the ultimate constraint on water marketing.

Article

The Qanat System of Iran and the Maghreb  

Ahmad Abbasnejad and Behnam Abbasnejad

A qanat is a kind of subterranean horizontal tunnel and usually excavated in soft sediments. It conducts groundwater to the surface at its emerging point. In addition to the tunnel, each qanat contains anywhere from several to hundreds of vertical wells for removal of dig materials and ventilation of the tunnel. These wells get increasingly deep until the deepest and last one, which is known as the mother well. According to the literature, qanat was first developed around 800 to 1000 bc in northwest of Iran and afterward was utilized in many other countries in Asia, Africa, southern Europe, and even (through independent invention) in the Americas. The areas utilizing the qanat have three characteristics in common: the shortage of surficial water (streams) indicating an arid or semiarid climate; suitable topographical slopes that help conduct groundwater to the surface for a distance by a gently sloping tunnel (qanat); and the presence of unconsolidated sediments (usually alluvial) that both act as subsurface reservoirs and as material that can be easily excavated using primitive tools. In another words, dry areas with mountain-plain topography, alluvial fans, and stream beds (wadis) are suitable for digging qanats. Major parts of Iran and some parts of the Maghreb have such conditions. This is why these two regions have been somewhat dependent on qanats for their water supply. Although the invention of qanats helped human settlement and welfare in drier countries, it had some negative impacts. The presence of humans due to qanats directly impacted the wildlife and vegetation cover of those areas. And in some cases, changes in the groundwater regime caused wilting and drying because of limited water resources for plants and wildlife. The history of qanat development may be viewed as undergoing three major stages in the dry zones of Iran and the Maghreb, as well as in many other countries where they are present. During the first stage, from 1,000 to 2,000 years after their introduction (depending upon the region) qanats rapidly proliferated as technology spread to new areas. During the second stage, new qanat construction halted, as they had been developed in almost all suitable areas. In the third stage, beginning in some places in the early 20th century, such factors as increasing demand for groundwater, technical developments in water well drilling, and problems with qanat maintenance and urban sprawl caused many qanats to dry out; their numbers in operation have dropped. This decline will continue with varying rates in different countries. Unfortunately, the rate of decline in Iran, the home country of qanats, is more than many other places. This is mainly due to mismanagement.

Article

The Science of Agroecology  

Juha Helenius, Alexander Wezel, and Charles A. Francis

Agroecology can be defined as scientific research on ecological sustainability of food systems. In addressing food production and consumption systems in their entirety, the focus of agroecology is on interactions and processes that are relevant for transitioning and maintaining ecological, economic, political, and social-cultural sustainability. As a field of sustainability science, agroecology explores agriculture and food with explicit linkages to two other widespread interpretations of the concept of agroecology: environmentally sound farming practices and social movements for food security and food sovereignty. In the study of agroecology as science, both farming practices and social movements emerge as integrated components of agroecological research and development. In the context of agroecology, the concept of ecology refers not only to the science of ecology as biological research but also to environmental and social sciences with research on social systems as integrated social and ecological systems. In agroecological theory, all these three are merged so that agroecology can broadly be defined as “human food ecology” or “the ecology of food systems.” Since the last decades of the 20th century many developments have led to an increased emphasis on agroecology in universities, nonprofit organizations, movements, government programs, and the United Nations. All of these have raised a growing attention to ecological, environmental, and social dimensions of farming and food, and to the question of how to make the transition to sustainable farming and food systems. One part of the foundation of agroecology was built during the 1960s when ecologically oriented environmental research on agriculture emerged as the era of optimism about component research began to erode. Largely, this took place as a reaction to unexpected and unwanted ecological and social consequences of the Green Revolution, a post–World War II scaling-up, chemicalization, and mechanization of agriculture. Another part of the foundation was a nongovernmental movement among thoughtful farmers wanting to develop sustainable and more ecological/organic ways of production and the demand by consumers for such food products. Finally, a greater societal acceptance, demand for research and education, and public funding for not only environmental ecology but also for wider sustainability in food and agriculture was ignited by an almost sudden high-level political awakening to the need for sustainable development by the end of 1980s. Agroecology as science evolved from early studies on agricultural ecosystems, from research agendas for environmentally sound farming practices, and from concerns about addressing wider sustainability; all these shared several forms of systems thinking. In universities and research institutions, agroecologists most often work in faculties of food and agriculture. They share resources and projects among scientists having disciplinary backgrounds in genetics (breeding of plants and animals), physiology (crop science, animal husbandry, human nutrition), microbiology or entomology (crop protection), chemistry and physics (soil science, agricultural and food chemistry, agricultural and food technology), economics (of agriculture and food systems), marketing, behavioral sciences (consumer studies), and policy research (agricultural and food policy). While agroecologists clearly have a mandate to address ecology of farmland, its biodiversity, and ecosystem services, one of the greatest added values from agroecology in research communities comes from its wider systems approach. Agroecologists complement reductionist research programs where scientists seek more detailed understanding of detail and mechanisms and put these into context by developing a broader appreciation of the whole. Those in agroecology integrate results from disciplinary research and increase relevance and adoption by introducing transdisciplinarity, co-creation of information and practices, together with other actors in the system. Agroecology is the field in sustainability science that is devoted to food system transformation and resilience. Agroecology uses the concept of “agroecosystem” in broad ecological and social terms and uses these at multiple scales, from fields to farms to farming landscapes and regions. Food systems depend on functioning agroecosystems as one of their subsystems, and all the subsystems of a food system interact through positive and negative feedbacks, in their complex biophysical, sociocultural, and economic dimensions. In embracing wholeness and connectivity, proponents of agroecology focus on the uniqueness of each place and food system, as well as solutions appropriate to their resources and constraints.

Article

The Street-Level Bureaucracy at the Intersection of Formal and Informal Water Provision  

Marie-Hélène Zérah

Street-level bureaucrats (SLBs) interact directly with users and play a key role in providing services. In the Global South, and specifically in India, the work practices of frontline public workers—technical staff, field engineers, desk officers, and social workers—reflect their understanding of urban water reforms. The introduction of technology-driven solutions and new public management instruments, such as benchmarking, e-governance, and evaluation procedures, has transformed the nature of frontline staff’s responsibilities but has not solved the structural constraints they face. In regard to implementing solutions to improve access in poor neighborhoods, SLBs continue to play a key role in the making of formal and informal provision. Their daily practices are ambivalent. They can be both predatory and benevolent, which explains the contingent impacts on service improvement and the difficulty in generalizing reform experiments. Nevertheless, the discretionary power of SLBs can be a source of flexibility and adaptation to complex social settings.

Article

Tomatoes: A Model Crop of Solanaceous Plants  

Raheel Anwar, Tahira Fatima, and Autar K. Mattoo

The modern-day cultivated and highly consumed tomato has come a long way from its ancestor(s), which were in the wild and not palatable. Breeding strategies made the difference in making desirable food, including tomato, available for human consumption. However, like other horticultural produce, the shelf life of tomato is short, which results in losses that can reach almost 50% of the produce, more so in developing countries than in countries with advanced technologies and better infrastructure. Food security concerns are real, especially taking into consideration that the population explosion anticipated by 2050 will require more food production and the production of more nutritious food, which applies as much to the tomato crop as the other crops. Today’s consumer has become aware and is looking for nutritious foods for a healthful and long life. Little was done until recently to generate nutritionally enhanced produce including fruits/vegetables. Also, extreme environments add to plant stress and impact yield and nutritional quality of produce. Recent developments in understandings of the plant/fruit genetics and progress made in developing genetic engineering technologies, including the use of CRISPR-Cas9, raise hopes that a better tomato with a high dose of nutrition and longer-lasting quality will become a reality.

Article

Toward a Holistic Environmental Aesthetic  

Nathalie Blanc

Environmental aesthetics encompasses aesthetic relationships to and in the environment, including an urban aesthetic and an aesthetic of nature—which emerged in the 18th and 19th centuries both from the sciences and from the distinction from the scientific in the aesthetic observations of nature. Environmental aesthetics notably comprises philosophical, artistic, and geographical work. Increasingly since the 1990s, the social and environmental crisis, and particularly climate change, is and has been causing shifts within this field of research and reflection. As of the 2020s, the admiration humans can bear toward nature is not without fear of its disappearance caused by their own activities. Ethics is more and more linked to aesthetics as humans are morally affected by this catastrophic environmental degradation. Thus, a certain anxiety quickly reveals itself in the face of planetary transformations. What can the geographer do? Since the 1990s, the discipline has been inviting thought about the environment from the aesthetic experience, challenging or interrogating the perception, understanding, and relationship to the natural surroundings. The geographer has been attempting to apprehend through creative research—such as “psychogeographical” situational walks (dérive, situation of inquiry, influence map), and, more generally, artistic works firmly rooted in the whole landscape question—the ways of redefining local situations and places. The need is to face three major challenges. First, there is the necessity to explore how planetary threats transform the perceptions of the environment. Anxieties reflect the difficulties of politics. Second, an aesthetic of the ordinary should be investigated as an ordinary environmentalism, meaning that which is related to the daily creation of environments. Third, the importance of research creation and ecoplastic forms of art needs to be highlighted (art and environment-making processes).

Article

Ancient and Traditional Agriculture, Pastoralism, and Agricultural Societies in Sub-Saharan Africa  

Andrew B. Smith

African domesticated animals, with the exception of the donkey, all came from the Near East. Some 8,000 years ago cattle, sheep, and goats came south to the Sahara which was much wetter than today. Pastoralism was an off-shoot of grain agriculture in the Near East, and those herders immigrating brought with them techniques of harvesting wild grains. With increasing aridity as the Saharan environment dried up around 5000 years ago, the herders began to control and manipulate their stands resulting in millet and sorghum domestication in the Sahel Zone, south of the Sahara. Pearl millet expanded to the south and was taken up by Bantu-speaking Iron Age farmers in the savanna areas of West Africa and then spread around the tropical forest into East Africa by 3000 b.p. As the Sahara dried up and the tsetse belts retreated, sheep and cattle also moved south. They expanded into East Africa via a tsetse-free environment of the Ethiopian highlands arriving around 4000 b.p. It took around 1000 years for the pastoralists to adapt to other epizootic diseases rife in this part of the continent before they could expand throughout the grasslands of Kenya and Tanzania. Thus, East Africa was a socially complex place 3000 years ago, with indigenous hunters, herders and farmers. This put pressure on pastoral use of the environment, so using another tsetse-free corridor from Tanzania, through Zambia to the northern Kalahari, then on to the Western Cape, herders moved to southern Africa, arriving 2000b.p. They were followed to the eastern part of South Africa by Bantu-speaking agro-pastoralists 1600 years ago who were able to use the summer rainfall area for their sorghum and millet crops. Control and manipulation of African indigenous plants of the forest regions probably has a long history from use by hunter-gatherers, but information on this is constrained by archaeological evidence, which is poor in tropical environments due to poor preservation. Evidence for early palm oil domestication has been found in Ghana dated to around 2550b.p. Several African indigenous plants are still widely used, such as yams, but the plant which has spread most widely throughout the world is coffee, originally from Ethiopia. Alien plants, such as maize, potatoes and Asian rice have displaced indigenous plants over much of Africa.

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Transboundary Water Governance and Small Basin Councils in Central Asia  

Stefanos Xenarios, Murat Yakubov, Aziza Baubekova, Olzhas Alshagirov, Zhassulan Zhalgas, and Eduardo Jr Araral

Central Asia (CA) hosts some of the world’s most complex and most extensive water management infrastructures allocated in the two major transboundary basins of the Amudarya and Syrdarya Rivers. The upstream countries of Tajikistan and Kyrgyzstan mainly utilize the rivers for hydropower and irrigation, whereas the downstream countries of Uzbekistan, Turkmenistan, and Kazakhstan primarily use them for irrigation purposes. The governance of the two river basins has been contested since Soviet times, and more so after the independence of the CA countries. The scheme of Small Basin Councils (SBCs) has been introduced in the region from 2010 to 2022 to improve local and transboundary water governance at a sub-basin and catchment level. Implementing SBCs in CA is still in the experimental phase, and its contribution to river basin management is insufficiently explored. However, there are indications that SBCs play a significant role in raising awareness of and engagement with local communities and improving local and transboundary governance management and coordination. Most important, SBCs can help resolve critical issues in agricultural water allocation, one of the most contentious issues for transboundary water governance in CA. The basin councils could become significant leverage for improving water governance on national and transboundary systems in CA by actively engaging local communities in management, planning, and administration.