•Southeast Asia has the highest rates of forest degradation and conversion in the tropics.•New research shows that forest conversion to cropland, especially oil palm, results in much greater losses ...of biodiversity than does even intensive logging.•There is little evidence that crops such as oil palm or rubber can be grown in ways that sustain forest-dependent species.•Preventing the conversion of logged forest to cropland should be a top priority of conservationists; moreover, it provides a cost-effective way to protect much (but not all) of the forest biodiversity of the region.
In 2004, Navjot Sodhi and colleagues warned that logging and agricultural conversion of Southeast Asia's forests were leading to a biodiversity disaster. We evaluate this prediction against subsequent research and conclude that most of the fauna of the region can persist in logged forests. Conversely, conversion of primary or logged forests to plantation crops, such as oil palm, causes tremendous biodiversity loss. This loss is exacerbated by increased fire frequency. Therefore, we conclude that preventing agricultural conversion of logged forests is essential to conserving the biodiversity of this region. Our analysis also suggests that, because Southeast Asian forests are tightly tied to global commodity markets, conservation payments commensurate with combined returns from logging and subsequent agricultural production may be required to secure long-term forest protection.
1. Two strategies are often promoted to mitigate the effects of agricultural expansion on biodiversity: one integrates wildlife-friendly habitats within farmland (land sharing), and the other ...intensifies farming to allow the offset of natural reserves (land sparing). Their relative merits for biodiversity protection have been subject to much debate, but no previous study has examined whether trade-offs between the two strategies depend on the proximity of farmed areas to large tracts of natural habitat. 2. We sampled birds and dung beetles across contiguous forests and agricultural landscapes (low-intensity cattle farming) in a threatened hotspot of endemism: the Colombian Chocó-Andes. We test the hypothesis that the relative biodiversity benefits of either strategy depend partially on the degree to which farmlands are isolated from large contiguous blocks of forest. 3. We show that distance from forest mediates the occurrence of many species within farmland. For the majority of species, occurrence on farmland depends on both isolation from forest and the proportionate cover of small-scale wildlife-friendly habitats within the farm landscape, with both variables having a similar overall magnitude of effect on occurrence probabilities. 4. Simulations suggest that the biodiversity benefits of land sharing decline significantly with increasing distance from forest, but land sparing benefits remain consistent. In farm management units situated close to large contiguous forest (<500 m), land sharing is predicted to provide equal benefits to land sparing, but land sparing becomes increasingly superior in management units situated further from forest (1500 m). The predicted biodiversity benefits of land sparing are similar across all distances, provided that sparing mechanisms genuinely deliver protection for contiguous forest tracts. 5. Synthesis and applications. The persistence of bird and dung beetle communities in low-intensity pastoral agriculture is strongly linked to the proximity of surrounding contiguous forests. Land-sharing policies that promote the integration of small-scale wildlife-friendly habitats might be of limited benefit without simultaneous measures to protect larger blocks of natural habitat, which could be achieved via land-sparing practices. Policymakers should carefully consider the extent and distribution of remaining contiguous natural habitats when designing agri-environment schemes in the tropics.
► An ideal agricultural system is sustainable, maintains and improves human health, benefits environment and produces enough food for increasing world population. ► The utilization of biofertlizers ...can decrease the use of urea-N, prevent the depletion of soil organic matter and reduce environmental pollution to a considerable extent. ► Cyanobacteria and PGPR are excellent model systems which can provide the biotechnologist with novel genetic constituents and bioactive compounds having diverse uses in agriculture and environmental sustainability.► PGPR and cyanobacteria offer an environmentally sustainable approach to increase crop production and soil health.
Sustainable agriculture is vital in today's world as it offers the potential to meet our agricultural needs, something that conventional agriculture fails to do. This type of agriculture uses a special farming technique wherein the environmental resources can be fully utilized and at the same time ensuring that no harm was done to it. Thus the technique is environment friendly and ensures safe and healthy agricultural products. Microbial populations are instrumental to fundamental processes that drive stability and productivity of agro-ecosystems. Several investigations addressed at improving understanding of the diversity, dynamics and importance of soil microbial communities and their beneficial and co-operative roles in agricultural productivity. However, in this review we describe only the contributions of plant growth promoting rhizobacteria (PGPR) and cyanobacteria in safe and sustainable agriculture development.
Global increases in population, consumption, and gross domestic product raise concerns about the sustainability of the current and future use of natural resources. The human appropriation of net ...primary production (HANPP) provides a useful measure of human intervention into the biosphere. The productive capacity of land is appropriated by harvesting or burning biomass and by converting natural ecosystems to managed lands with lower productivity. This work analyzes trends in HANPP from 1910 to 2005 and finds that although human population has grown fourfold and economic output 17-fold, global HANPP has only doubled. Despite this increase in efficiency, HANPP has still risen from 6.9 Gt of carbon per y in 1910 to 14.8 GtC/y in 2005, i.e., from 13% to 25% of the net primary production of potential vegetation. Biomass harvested per capita and year has slightly declined despite growth in consumption because of a decline in reliance on bioenergy and higher conversion efficiencies of primary biomass to products. The rise in efficiency is overwhelmingly due to increased crop yields, albeit frequently associated with substantial ecological costs, such as fossil energy inputs, soil degradation, and biodiversity loss. If humans can maintain the past trend lines in efficiency gains, we estimate that HANPP might only grow to 27–29% by 2050, but providing large amounts of bioenergy could increase global HANPP to 44%. This result calls for caution in refocusing the energy economy on land-based resources and for strategies that foster the continuation of increases in land-use efficiency without excessively increasing ecological costs of intensification.
1. Agricultural land use threatens ecosystem services such as biological control by natural enemies because of simplification of habitat structure and intensification of disturbance and agrochemical ...inputs. Low parasitism rates of agricultural pests have typically been attributed to a lack of resources for parasitoids in highly simplified landscapes, but this could be confounded by the nearly ubiquitous correlation between landscape complexity and the cover of intensively farmed agricultural crops. 2. Here, we disentangle the mechanisms driving landscape-scale effects on host—parasitoid interactions by taking advantage of a landscape modification gradient in which the diversity of habitat types and annual crop cover in the landscape were uncorrelated. We quantified herbivore densities and parasitism and hyperparasitism rates on two important crop pests (aphids and Plutella xylostella) across 30 landscapes. We used structural equation modelling (SEM) to test whether land-use intensity (insecticide application and habitat disturbance) or resource availability for parasitoids (floral resources and alternative host plants) was mediating the effects of habitat diversity and annual crop cover on the landscape. 3. Rates of primary- and hyperparasitism of aphids and primary parasitism of P. xylostella decreased with increasing annual crop cover, whereas decreasing habitat diversity in the landscape had little effect on parasitism rates. These effects were mediated almost entirely by greater habitat disturbance and greater frequency of insecticide application, rather than by changes in resource availability. 4. Parasitoids were more sensitive to intensive farming practices than were their herbivore hosts, and in turn hyperparasitoids were more sensitive than were primary parasitoids. This supports the theoretical prediction that higher trophic levels should be increasingly sensitive to the disturbances associated with land-use change. 5. Synthesis and applications. Our work suggests that increased land-use intensity (e.g. higher insecticide inputs and greater levels of disturbance associated with increasing area of annual crops) has been underestimated as a driver of landscape effects on host—parasitoid interactions. These findings have important implications for the maintenance of ecosystem services such as biological control. The promotion of low-intensity farming practices that limit the extent and frequency of agrochemical inputs and habitat disturbances will be essential for the maintenance of effective biological control by parasitoids in agroecosystems.
In recent years, the transition to sustainability at a food systems’ scale has drawn major attention both from the scientific and political arenas. Agroecology has become central to such discussions, ...while impressive efforts have been made to conceptualize the agroecology scaling process. It has thus become necessary to apply the concept of agroecology transitions to the scale of food systems and in different “real-world” contexts. Scaling local agroecology experiences of production, distribution, and consumption, which are often disconnected and/or disorganized, also reveals emergent research gaps. A critical review was performed in order to establish a transdisciplinary dialogue between both political agroecology and the literature on sustainable food systems. The objective was to build insights into how to advance towards Agroecology-based Local Agri-food Systems (ALAS). Our review unveils emergent questions such as: how to overcome the metabolic rift related to segregated activities along the food chain, how to feed cities sustainably, and how they should relate to the surrounding territories, which social subjects should drive such transitions, and which governance arrangements would be needed. The paper argues in favor of the re-construction of food metabolisms, territorial flows, plural subjects and (bottom-up) governance assemblages, placing life at the center of the food system and going beyond the rural–urban divide.
Objective: To analyze the results of the management of grazing sows at international scale, as well as the elements of waste in field and confinement, which contribute to the resilience of pig ...husbandry systems. Materials and Methods: The results of more than 80 publications about the elements of the management of grazing sows: main grazing systems, se of plant genetic resources in their feeding under different climate conditions, stocking rate, quality of the ration, breed, category, as well as waste recycling, applicable to the conditions of the tropic, were analyzed. Results: There is innovative evidence in the management of grazing sows with the use of different plant genetic resources, in systems that go from subsistence to intensive management with electrical fence. The conditions or requisites for management, effect of stocking rate, species, importance of the nutritional value and animal category (mainly with sows), recycling in grazing and semi-confinement (deep litter), are analyzed. Conclusions: Pig feeding based on pastures and forages, mainly, implies different management, with different solutions from the ones that are applied in conventional confined systems with concentrate feeds. The agroecological management and use of adequate plant genetic resources are the ways for resilient and sustainable production in the face of climate change, which contributes to food sovereignty.
The term agroecology has undergone broad diversification since it was first conceived as the study of the ecology of agricultural systems. In addition to the "tripartite" definition, which includes ...science, practice, and social movement, political and "emancipatory" agroecologies, among others, are included. There is no consensus on the meaning of "agroecology" and "agroecological," nor the objectives and uses associated with those concepts. Thus, despite the concept of "agroecology" not being consolidated nor unisemic, its meaning and application continue to diversify according to the interests and perspectives of the users. That diversification encompasses different ways of looking at agriculture's role in human societies and the environment in which they are based and function. Agroecology, too, has been seen as an activity whose objectives include issues as diverse as mythical, ceremonial, dogmatic, political, or religious. Moreover, this unrestricted diversification also devalues and trivializes the term and hinders the mutual understanding among academics, practitioners, promoters, decision-makers, the public, and government agencies. We begin a series of reflections on the various agroecologies in Mexico that we hope will promote the formation of clear, well-defined, and documented concepts to contribute to synergies among agroecologies and the advancement of their objectives.
Initiatives to reduce the reliance of agriculture on pesticides, including the European Union (EU) Directive 2009/128/EC on the sustainable use of pesticides (SUD), have yet to lead to widespread ...implementation of Integrated Pest Management (IPM) principles. Developments in weed management have strongly focused on increasing the efficiency of herbicides or substituting herbicides with other single tactics such as mechanical control. To increase sustainability of agricultural systems in practice, a paradigm shift in weed management is needed: from a single tactic and single growing season approach towards holistic integrated weed management (IWM) considering more than a single cropping season and focusing on management of weed communities, rather than on control of single species. To support this transition, an IWM framework for implementing a system level approach is presented. The framework consists of five pillars: diverse cropping systems, cultivar choice and establishment, field and soil management, direct control and the cross-cutting pillar monitoring and evaluation. IWM is an integral part of integrated pest management (IPM) and adopting IWM will serve as a driver for the development of sustainable agricultural systems of the future.
•Integrated weed management (IWM) is an integral part of integrated pest management (IPM) and adopting IWM will serve as an important driver for sustainable IPM.•A paradigm shift in weed management is needed from single tactic and single growing season approaches towards a holistic IWM approach.•A generic framework for holistic IWM is proposed to support agronomists and weed scientist to design novel weed management strategies.•The IWM framework is based on five pillars: diverse cropping systems, cultivar choice and establishment, field and soil management, direct control and the cross-cutting pillar monitoring and evaluation.
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