Mariana Edith Marasas
Bio: Mariana Edith Marasas is an academic researcher from National University of La Plata. The author has contributed to research in topic(s): Agroecology & No-till farming. The author has an hindex of 7, co-authored 32 publication(s) receiving 231 citation(s).
TL;DR: It is concluded that tillage systems affect not only the abundance of arthropod fauna but also the proportion between different functional groups, and the consequences for soil quality are discussed later on.
Abstract: Different functional groups of soil arthropodofauna present in the agro-ecosystem can be severely modified by tillage practices. The abundance of different trophic groups subject to conventional tillage (CT) and no tillage (NT) practices were evaluated compared to a natural field boundary (FB) in a wheat crop. Arthropods were captured using pitfall traps and collected every 20 days during 10 months, and grouped according to their habits in predators, phytophagous and detritivorous. Tillage systems affected the abundance of arthropod fauna and the proportion between different functional groups as regards a FB. Predators constituted the most abundant group of all arthropods captured, and their number was higher under NT than under CT. In CT, an increase in predators was observed only in spring, probably associated with a recolonisation from the adjacent plots of NT. Phytophagous was the least representative group in the three evaluated systems, it was higher under cropped plots (NT and CT) than in the FB, and was not affected by tillage practices. Under NT, the number of predators, remained higher along the crop development. Phytophagous activity in no till plots remains constant. In FB, the number of captured individuals was lower and relatively stable along the whole sampling period than in the cultivated plots. Ploughing action (CT plots) provoked a decrease in the relative importance of predators and an increase in phytophagous as regards those in NT and FB. Total biomass of captured arthropod fauna showed significant differences between treatments, being higher in NT and lower in CT plots. It is concluded that tillage systems affect not only the abundance of arthropod fauna but also the proportion between different functional groups. The consequences of these changes for soil quality are discussed later on.
Abstract: The ecological principles underlying traditional agricultural management practices are not always understood. On the coast of Berisso, Argentina, traditional management practices are applied to “old” vineyards located in flood plain areas, subject to periodic floods. Over the last few years, “new” vineyards have been planted at slightly higher altitudes, protecting them from river flooding. Despite the ecological differences between the low and high areas, farmers have largely extended traditional management practices to the new vineyards. This study was undertaken to evaluate the risks involved when traditional agricultural management practices are applied to different ecological settings while the underlying ecological principles of those practices are not well understood. The evaluation relies on three distinct sections: (1) assessing the sustainability of a traditional vineyard management system, (2) analyzing its underlying ecological principles and (3) investigating the potential consequences of applying management practices utilized in flood plain zones to higher altitudes. To carry out the evaluation, a methodology based on indicators was used. In particular, an evaluation was developed to examine traditional vineyard management effects on both internal resources, such as soil properties and biodiversity, and external resources, such as nonrenewable energy and water resources. In old vineyards situated within the flood plain, traditional management practices recycle organic matter, preserve biodiversity, provide for an efficient use of nonrenewable energy and ensure a low risk of underground water contamination from pesticides. Furthermore, the soil nutrient balance is maintained via nutrient input from river sediments. In contrast, new vineyards present a negative soil nutrient balance. Our findings thus suggest that traditional management practices are ecologically sound when considered within their original ecological context, but may be inappropriate in new ecological settings.
TL;DR: Changes in edaphic carabidofauna abundance in a wheat crop plot, its field margins, and four semi-natural adjacent habitats were evaluated, finding a low specific richness of carabids was found in the wheat crop.
Abstract: Changes in edaphic carabidofauna abundance in a wheat crop plot, its field margins, and four semi-natural adjacent habitats were evaluated. A low specific richness of carabids was found in the wheat crop. No species was found exclusively in the wheat plot, but there were species found in the surrounding habitat. The observed responses of different species regarding moisture conditions determined their presence or absence in these semi-natural habitats as well as in dominance structures of each particular ambient. A gradual decrease in the number of captured individuals from the field margin to the center of the wheat plot was observed. Semi-natural habitats and field margins become an important requirement for habitat and shelter of the best represented species of ground beetles, particularly for predatory and omnivorous varieties.
01 Apr 2013
Abstract: Perez, M., Marasas, M.E. (2013). Regulating services and management practices: contributions to horticulture with agroecological bases. Ecosistemas 22(1):36-43. Doi.: 10.7818/ECOS.2013.22-1.07 The importance of agroecological management practices has been widely discussed in the literature. The relationship between these practices and the regulating services in agroecosystems is an essential contribution to the development of sustainable production systems. This paper analyzes the relationship between agroecological management practices in horticulture and different regulating services to farm scale. It aims to establish a framework that facilitate technicians, researchers and policy makers, advancing technological alternatives that promote agroecological transition processes. Knowledge of the interactions between practices and services is necessary for decision making concerning the agro-ecosystems management and biodiversity conservation, particularly in agricultural systems.
01 Jan 2015
Abstract: Agroecology emerges as a new approach and paradigm of agricultural science that aims to provide strategies and criteria for the design, evaluation and management of sustainable agroecosystems. It appears in different institutions and organizations, as a reaction to the increasingly obvious consequences of environmentally unsustainable and socially exclusive production model derived from the philosophy of the Green Revolution. Because of its multidisciplinary and pluriepistemological character as scientific approach, as a movement and as a series of strategies and techniques, the incorporation and consolidation of agroecology in Argentina, recognizes different goals, actors and stages. Among the institutions may be mentioned non-governmental organizations, state institutions and universities and other agricultural education institutions as well as farmers organizations. These stages are analyzed and the potentials and limitations for future expansion are discussed.
Abstract: Conservation agriculture (CA) changes soil properties and processes compared to conventional agriculture. These changes can, in turn, affect the delivery of ecosystem services, including climate regulation through carbon sequestration and greenhouse gas emissions, and regulation and provision of water through soil physical, chemical and biological properties. Conservation agriculture can also affect the underlying biodiversity that supports many ecosystem services. In this overview, we summarize the current status of the science, the gaps in understanding, and highlight some research priorities for ecosystem services in conservational agriculture. The review is based on global literature but also addresses the potential and limitations of conservation agriculture for low productivity, smallholder farming systems, particularly in Sub Saharan Africa and South Asia. There is clear evidence that topsoil organic matter increases with conservation agriculture and with it other soil properties and processes that reduce erosion and runoff and increase water quality. The impacts on other ecosystem services are less clear. Only about half the 100+ studies comparing soil carbon sequestration with no-till and conventional tillage indicated increased sequestration with no till; this is despite continued claims that conservation agriculture sequesters soil carbon. The same can be said for other ecosystem services. Some studies report higher greenhouse gas emissions (nitrous oxide and methane) with conservation agriculture compared to conventional, while others find lower emissions. Soil moisture retention can be higher with conservation agriculture, resulting in higher and more stable yields during dry seasons but the amounts of residues and soil organic matter levels required to attain higher soil moisture content is not known. Biodiversity is higher in CA compared to conventional practices. In general, this higher diversity can be related to increased ecosystem services such as pest control or pollination but strong evidence of cause and effect or good estimates of magnitude of impact are few and these effects are not consistent. The delivery of ecosystem services with conservation agriculture will vary with the climate, soils and crop rotations but there is insufficient information to support a predictive understanding of where conservation agriculture results in better delivery of ecosystem services compared to conventional practices. Establishing a set of strategically located experimental sites that compare CA with conventional agriculture on a range of soil-climate types would facilitate establishing a predictive understanding of the relative controls of different factors (soil, climate, and management) on ES outcomes, and ultimately in assessing the feasibility of CA or CA practices in different sites and socioeconomic situations. The feasibility of conservation agriculture for recuperating degraded soils and increasing crop yields on low productivity, smallholder farming systems in the tropics and subtropics is discussed. It is clear that the biggest obstacle to improving soils and other ES through conservation agriculture in these situations is the lack of residues produced and the competition for alternate, higher value use of residues. This limitation, as well as others, point to a phased approach to promoting conservation agriculture in these regions and careful consideration of the feasibility of conservation agriculture based on evidence in different agroecological and socioeconomic conditions.
TL;DR: Five additional avenues that agronomic research could follow to strengthen the ecological intensification of current farming systems are proposed, assuming that progress in plant sciences over the last two decades provides new insight of potential use to agronomists.
Abstract: Agriculture is facing up to an increasing number of challenges, including the need to ensure various ecosystem services and to resolve apparent conflicts between them. One of the ways forward for agriculture currently being debated is a set of principles grouped together under the umbrella term “ecological intensification”. In published studies, ecological intensification has generally been considered to be based essentially on the use of biological regulation to manage agroecosystems, at field, farm and landscape scales. We propose here five additional avenues that agronomic research could follow to strengthen the ecological intensification of current farming systems. We begin by assuming that progress in plant sciences over the last two decades provides new insight of potential use to agronomists. Potentially useful new developments in plant science include advances in the fields of energy conversion by plants, nitrogen use efficiency and defence mechanisms against pests. We then suggest that natural ecosystems may also provide sources of inspiration for cropping system design, in terms of their structure and function on the one hand, and farmers’ knowledge on the other. Natural ecosystems display a number of interesting properties that could be incorporated into agroecosystems. We discuss the value and limitations of attempting to ‘mimic’ their structure and function, while considering the differences in objectives and constraints between these two types of system. Farmers develop extensive knowledge of the systems they manage. We discuss ways in which this knowledge could be combined with, or fed into scientific knowledge and innovation, and the extent to which this is likely to be possible. The two remaining avenues concern methods. We suggest that agronomists make more use of meta-analysis and comparative system studies, these two types of methods being commonly used in other disciplines but barely used in agronomy. Meta-analysis would make it possible to quantify variations of cropping system performances in interaction with soil and climate conditions more accurately across environments and socio-economic contexts. Comparative analysis would help to identify the structural characteristics of cropping and farming systems underlying properties of interest. Such analysis can be performed with sets of performance indicators and methods borrowed from ecology for analyses of the structure and organisation of these systems. These five approaches should make it possible to deepen our knowledge of agroecosystems for action.
01 Jan 2012
Abstract: Conservation agriculture has been proposed as a widely adapted set of management principles that can assure more sustainable agricultural production. Conservation agriculture removes the emphasis from the tillage component alone and addresses a more enhanced concept of the complete agricultural system. Applying conservation agriculture essentially means altering literally generations of traditional farming practices and implement use. Within the framework of agricultural production, high soil quality equates to the ability of the soil to maintain a high productivity without significant soil or environmental degradation. A comparative soil quality evaluation is one in which the performance of the system is determined in relation to alternatives. Inconsistent effects of a reduction in tillage on the variation in total porosity with depth may be related to differences in traffic on different sites, or on soil quality at the time tillage was reduced or stopped.
Abstract: Vineyards represent one of the most erosion-prone types of cultivated land. Because of this, cultivation practices are very important in reducing the soil erosion risk in vineyard regions. The aim of this paper was to assess the impact of various management practices on soil loss in vineyards. Effects of tillage, hoeing, rotavating and grass cover were evaluated in small vineyards located in southwestern Slovakia in the Vrable viticultural district. Erosion and deposition rates were estimated using the levelling method. This method is based on an evaluation of variability of the soil surface against vineyard poles measured between the year of pole insertion and the year of measurement. On the basis of the measured data, a WATEM/SEDEM distributed soil erosion model was calibrated, and the total soil loss from the vineyards under different management conditions was estimated. The model shows rather good performance in modelling soil erosion, but at the same time, it shows lower reliability in modelling soil deposition. Downslope tilled vineyards were the most eroded; the erosion in rotavated vineyards is somewhat reduced. The most protective tillage system is hoeing. Considerably lower soil loss was estimated with the use of vegetation cover between vine rows, which is in accordance with agro-environmental schemes supporting use of grass cover as an erosion prevention measure in vineyards. Copyright © 2012 John Wiley & Sons, Ltd.
Abstract: Despite the wine industry's reputation as being environmentally safe, prior research has shown the cultivation of wine grapes and production of wine to be associated with a large number of environmental concerns. The present study utilised an integrative literature review to investigate key areas of environmental concern currently faced by organisations in the global wine industry. Concerns discussed include water use and quality, the generation and management of organic and inorganic waste streams, energy use and the production of greenhouse gas emissions, chemical use, land use issues and the impact on ecosystems. The review reveals current practice within wine organisations to be largely unexplored and inadequate. Practice is characterised by a lack of the quantitative environmental data required if the industry is to bring about lasting environmental improvement to operational processes, products, and towards economically and environmentally improved performance.