Intensive Use Of Agrochemicals Research Articles

Biochar and earthworms working in tandem: Research opportunities for soil bioremediation

Intensive use of agrochemicals is considered one of the major threats for soil quality. In an attempt to mitigate their side-effects on non-target organisms and soil functioning, many engineering and biological remediation methodologies are currently available. Among them, the use of biochar, a carbonaceous material produced from pyrolysing biomass, represents an attractive option enhancing both remediation and soil carbon storage potentials. Currently, activation of biochar with chemical or physical agents seeks for improving its remediation potential, but most of them have some undesirable drawbacks such as high costs and generation of chemical wastes. Alternatively, the use of biological procedures to activate biochar with extracellular enzymes is gaining acceptance mainly due to its eco-friendly nature and cost-effectiveness. In these strategies, microorganisms play a key role as a source of extracellular enzymes, which are retained on the biochar surface. Recently, several studies point out that soil macrofauna (earthworms) may act as a biological vector facilitating the adsorption of enzymes on biochar. This paper briefly introduces current biochar bioactivation methodologies and the mechanisms underlying the coating of biochar with enzymes. We then propose a new conceptual model using earthworms to activate biochar with extracellular enzymes. This new earthworm-biochar model can be used as a theoretical framework to produce a new product “vermichar”, vermicompost produced from blended feedstock, earthworms, and biochar that can be used to improve soil quality and remove soil contaminants. This model can also be used to develop innovative in-situ “vermiremediation” technologies utilizing the beneficial effects of both earthworms and biochar. Since biochar may contain toxic chemicals generated during its production stages or later concentrated when applied to polluted soils, this paper also highlights the need for an ecotoxicological knowledge around earthworm-biochar interaction, promoting further discussion on suitable procedures for assessing the environmental risk of this conceptual model application in soil bioremediation.

Alternative biodegradation pathway of the herbicide diuron

Native soil microbiota is important to maintain the quality of the environment, but with the intensive use of agrochemicals, changes in microbial biomass and formation of toxic waste have been observed. Studies have emphasized the importance of using bioremediation to reduce the diuron in the environment, as well as other pesticides. The biodegradation of diuron is usually described under aerobic conditions, in which microorganisms perform an N-demethylation of the urea group and subsequent hydrolysis, producing three different metabolites: 3-(3,4-dichlorophenyl)-3-methylurea, 3,4-dichlorophenylurea, and 3,4-dichloroaniline. In this study, the biodegradation of this herbicide by bacteria isolated from a sugarcane cultivation area and the degradation pathway of diuron were evaluated. The metabolites generated from diuron biodegradation were analyzed by High Performance Liquid Chromatography coupled to a mass spectrometer with an electrospray ionization source and ion trap analyzer. Isolate S204, identified as Escherichia fergusonii by sequencing of the 16S rDNA, adk, gyrB and recA was able to remove the chlorine from the herbicide molecule, as well as forming the metabolites already described. Therefore, these results suggest that isolate S204 can degrade diuron by a different pathway not yet described.

Brazilian Agribusiness and the Consequences of the Intensive Use of Agrochemicals

To meet the continued growth of the population and to extinguish the hunger that still affects 800 million of those living in underdeveloped countries, the increase in the supply of food is becoming more urgent. However, it is also essential to reduce the use of pesticides, in order to offer a better quality food, with less negative impacts on the environment and on the human health, through polycultures grown in smaller areas of plantations. This work, based on a bibliographical research, aims to present some of the risks and consequences arising from the use of agrochemicals in Brazil. On one hand, they enable the cultivation of monocultures, and on the other, they affect the health of farm workers, consumers and the environment. Therefore, this study aims to contribute to the discussion about the risks of pesticides. And as a result, arguments corroborating the idea that the great challenge is to rethink industrial agriculture and begin a transition of food systems, based on a sustainable, biodiversity-based and socially fair agricultural model.

Misguided policy may jeopardize a diverse South brazilian environmental protection area

Abstract: The Devonian Escarpment (DEEPA), located in the south of Brazil, represents an important area of environmental preservation composed by grasslands, gallery forests, as well as rock outcrops and archaeological sites. A law project (LP 527/2016), which suggests a reduction of the DEEPA area in approximately 70% of its original area (from 393,579 to 125,895 ha), is currently being processed in the Paraná State House of Representatives. Such reduction seems to be related to economic interests (mainly agriculture and mining) in the state of Paraná. If approved, LP 527/2016 will allow farmers to deliberately expand their activities, with the suppression of natural forest as main consequence. Additionally, loss of faunal diversity, contamination of water and soils, and alteration in nutrient cycles are expected, due the intensive use of agrochemicals. In addition to the direct environmental consequences, we expect the disappearance of areas of high geological interest, reducing local geodiversity, as well as substantial economic losses with ecotourism. Brazil is a signatory to the United Nations Convention on Biological Diversity, where it undertakes to develop strategies to prevent biodiversity loss and ecosystem degradation by 2020. An approval of the LP would be contradictory, considering that there are few natural vegetation areas in this region of the country. We emphasize that the proposal of such projects goes against the sustainability in the country and disregard the scientific knowledge generated until then. Thus, it is necessary to develop regional and federal political objectives that guarantee economic development in a balanced way, considering the local bio and geodiversity, not the proposal of mechanisms that destroy them.

Examining the legal safeguards against the environmental impact of land grabbing in African countries

Large-scale land acquisitions in African countries by foreign investors who use such lands for agricultural purposes that have negative socio-economic and environmental impact in host countries is considered as ‘land grabbing in Africa’. In the context of the environment, the type of crops and monoculture practices undertaken by the foreign investors led to changes in land use, deforestation, exposure of land to soil erosion, depletion of water sources, pollution of surface water and contamination of ground water as a result of the intense use of agro-chemicals. Collectively, these have had a deleterious environmental impact in host countries. This article examines the phenomenon of ‘land grabbing in Africa’ by identifying the type of land-based agricultural investments by foreign entities and the environmental impact of such investments in African countries like Nigeria. The article argues that the prevailing Nigerian environmental law cannot ensure sustainable development as it does not address the environmental impact of land-based agricultural investments by foreign enterprises in the country. The article proposes that suitable environmental laws must contain the concepts of Community Participation in environmental impact assessment process of land based foreign investments and Environmental Justice for victims of environmental degradation of such investments.

Management matters: A comparison of ant assemblages in organic and conventional vineyards

Abstract Agriculture is one of the dominant types of soil use throughout the world, and understanding patterns of species distributions across agroecosystems is a significant challenge for the future. The intensive use of agrochemicals affects the presence and distribution of several taxa, and organic agricultural methods are believed to be more environmentally sound than conventional ones. In general, organically grown crops host higher species richness for many different taxa, although this evidence is not always unequivocal. The aim of this study was to contribute to understanding whether different management options (organic vs. conventional) affect ant assemblages in vineyards, one of the most important permanent crops in Mediterranean-type environments. To this purpose, we analyzed ant assemblages from organic and conventional vineyards in the Chianti area, Italy. To reduce confounding effects, we chose vineyards with similar soil management (frequency of tillage) and placed within a comparable habitat matrix. The results of this study showed that organic and conventional vineyards hosted a similar species pool, but the structure of their assemblages differed and the effect of insecticides particularly appears to be relevant. Both ant abundance and the number of species per unit area were significantly greater in organic than conventional vineyards. The use of insecticides appeared to be particularly relevant given that vineyards that did not use insecticides also had greater alpha and beta diversity than vineyards where these chemicals were used.

Changes in bacterial community after application of three different herbicides.

The native soil microbiota is very important to maintain the quality of that environment, but with the intensive use of agrochemicals, changes in microbial biomass and formation of large quantities of toxic waste were observed in soil, groundwater and surface water. Thereby, the goal of this study was to evaluate if the selective pressure exerted by the presence of the herbicides atrazine, diuron and 2,4-D changes the bacterial community structure of an agricultural soil, using denaturing gradient gel electrophoresis technique. According to PERMANOVA analysis, a greater effect of the herbicide persistence time in the soil, the effect of the herbicide class and the effect of interaction between these two factors (persistence time and herbicide class) were observed. In conclusion, the results showed that the selective pressure exerted by the presence of these herbicides altered the composition of the local microbiota, being atrazine and diuron that most significantly affected the bacterial community in soil, and the herbicide 2,4-D was the one that less altered the microbial community and that bacterial community was reestablished first.

O conhecimento de produtores rurais do município de Arealva, SP, Brasil sobre as regras de uso dos agrotóxicos

Since the 1970s, the environmental consequences of the intensive use of agrochemicals have aroused the interests and concerns of technicians, scientists, and government agencies because possible contaminations caused by these substances. However, a major problem to be considered is the correct destination of pesticide containers after the use of the products, a liability resulting from the intensification of the use of pesticides formerly treated as common waste, or even dumped in the environment. This paper discussed the results obtained in the work carried out in Arealva City in São Paulo State, approaching the importance of the GEDAVE System (Animal and Plant Protection Management System), from use to the return of empty packaging, promoting better monitoring of the use and minimizing risks of this products. It was observed that farmers know the general rules that involve the rational use of agrochemicals, however, they still have difficulties in the practical applications regarding the storage in the rural property and the logistics of returning empty containers. So it was observed the necessity of the itinerant gathering with frequency, like tool that will solve the logistic difficulties reported.

Effects of probiotics on soil microbial activity, biomass and enzymatic activity under cover crops in field and greenhouse studies

Intensive use of agro-chemicals over the past few decades has increased land productivity, however, frequent application of agro-chemicals has also resulted in some negative impacts on the environment and soil microbial biodiversity. Use of alternative management such as probiotics is believed to promote soil microbial biodiversity and enzymatic activity. This research was conducted at the Natural Resources Conservation Service Soil Health Farm, Chariton County, Missouri to quantify probiotic effects on soil biological diversity and activity. Prior to 2012, the site was comprised of conventional corn (Zea mays L.)-soybean (Glycine max L.) rotation with tillage and chemical fertilizer use. Soil amendment with probiotics (Bio-Ag) included a non-treated control, and dosages at 60 L probiotic ha−1 year−1; 90 L probiotic ha−1 year−1; and 120 L probiotic ha−1 year−1 with three replications. Two equal split soil applications of probiotics were applied in September 2013 and May 2014. Soil samples were collected in August (pre-treatment), September 2013 and June 2014 from 0 to 6 cm depth. A greenhouse study was conducted using soil cores. Treatments were similar those in the field study except the low dose was excluded and higher dose of 150 L ha−1 year−1 was used. Soil microbial biomass and community structures were analyzed using phospholipid fatty acid analysis. Standard soil enzyme assays were used to assess microbial activity. Saprophytic fungi, protozoa and rhizobia biomass were significantly higher with 120 L probiotic ha−1 year−1 dose than control in the field study (p < 0.10). Total microbial biomass was significantly increased and saprophytic fungi biomass was more than two times higher with the 120 L ha−1 year−1 dose compared with the control in the greenhouse study at the December 2014 sampling. In the field study, principal component analysis revealed that PC1 and PC2 accounted for 62 % of total variance. Increasing trends in the values of soil fungal communities, rhizobia, dehydrogenase, β-glucosaminidase and fluorescein diacetate hydrolase with the 120 L probiotic ha−1 year−1 dose implies that probiotics can be used to improve soil quality indicators.

Rabbit Abundance Influences Predation on Bird Nests in Mediterranean Olive Orchards

Abstract. In recent decades, the intensification of agricultural practices in olive orchards, including intensive use of agrochemicals, along with the absence of natural herb layer, has led to a decline in songbird communities. Increased nest predation has been suggested as another important factor in the decline of farmland birds. High abundances of alternative prey species, such as European Rabbits Oryctolagus cuniculus may attract generalist predators, which may increase predation rates on bird nests, a phenomenon known as hyperpredation. In this work, we evaluate artificial nest predation in intensively farmed olive orchards, using quail eggs (one plaster and two natural eggs in each nest) placed on the ground (97 nests) and on trees (106 nests). 53.7% of nests (109 out of 203) were predated; 51 of these nests had at least one egg with signs of predation and in 58 nests all eggs were predated. Nests placed on the ground (61%) were predated more frequently than those on trees (46%). Rabbit abundance wa...

Evaluation of single extraction procedures for the assessment of heavy metal extractability in citrus agricultural soil of a typical Mediterranean environment (Argolida, Greece)

Heavy metals are natural soil constituents; however, the intense use of agrochemicals can increase total contents above background levels as well as the available fractions of the more toxic elements. In this study, the occurrence of some metals was investigated in agricultural soils from an intensely farmed rural area of Greece (Argolida) aiming to evaluate the various available pools and examine their relationship with the reactive and pseudototal soil fraction. Thirty soil samples were selected from a large database of a previous geochemical survey in the study area. The pseudototal (aqua regia), reactive (0.43 M HNO3), potentially phytoavailable (0.05 M EDTA), mobilizable (0.43 M HAc), and mobile (0.01 M CaCl2) pools of Cu, Zn, Cd, and Mn were determined. Soil properties were also examined including pH, total organic carbon, calcium carbonate content, and amorphous Al, Mn, and Fe oxides. In order to combine all geochemical information and elucidate the association between available metal pools and soil chemical characteristics, multiple linear regression was employed. The various proportions of available metal pools (%) were expressed as a function of the pseudototal or reactive metal content and general soil properties. The mobile pool of trace elements in the studied soils was quite low, while notable amounts of Cu were released by EDTA indicating a greater tendency for complexation. The acetic acid extraction yielded increased percentages of Cd and Mn and for these elements the reactive pools were quite representative of the pseudototal content. Extractable amounts of Zn by all the applied reagents were very low indicating that a considerable part of this metal is of geogenic origin. The empirical regression models showed that prediction of the available pools of Cu, Zn, and Cd from the pseudototal and reactive content is feasible. Although pH is known to be a key factor of at least exchangeable metal pools, its narrow range blurs its influence in the present study. The relatively low extraction yields of the studied elements show that the potential hazard of metal transfer to plants in the area is minimal despite some elevated pseudototal concentrations. The geochemical reactive and various available pools of Cu, Zn, and Cd in Mediterranean calcareous citrus soils can be determined by a single soil extraction test using dilute nitric acid.

Natural Enemies of the Frankliniella Complex Species (Thysanoptera: Thripidae) in Ataulfo Mango Agroecosystems.

A field survey was conducted in Ataulfo mango (Mangifera indica L.) orchards in Chiapas, Mexico, with the objective of determining the natural enemies of the Frankliniella complex species (Thysanoptera: Thripidae). Seven species of this genus feed and reproduce in large numbers during the mango flowering. Two representative orchards were selected: the orchard “Tres A” characterized by an intensive use of agrochemicals directed against thrips, and the orchard “La Escondida” that did not spray insecticides. During mango flowering, five inflorescences were randomly collected every 5 d in both orchards, for a total of 18 sampling dates. Results revealed the presence of 18 species of arthropods that were found predating on Frankliniella. There were 11 species in the families Aeolothripidae, Phlaeothripidae, Formicidae, Anthocoridae and Chrysopidae; and seven species of spiders in the families Araneidae, Tetragnathidae, and Uloboridae. Over 88% of predators were anthocorids, including, Paratriphleps sp. (Champion), Orius insidiosus (Say), Orius tristicolor (White), and O. perpunctatus (Reuter). The orchard that did not spray insecticides had a significantly higher number of predators suggesting a negative effect of the insecticides on the abundance of these organisms.

Влияние агрохимикатов на смертность от злокачественных новообразований женских гениталий в сельской местности Республики Дагестан

The paper presents the data on the influence of remote consequences separate, combined and cumulative impact of agrochemicals (fertilizers and pesticides) on female mortality (1997-2006) from malignant tumors of the genitalia in the rural areas of the Republic of Dagestan. The intensive use of agrochemicals before 1995 exceeded the critical load level according to data of V.I. Polchenko and co-authors (3.93 kg/ha) and the classification of World Health Organization (4,0-5,0 kg/ha) in ten times and more. As objective quantitative indicators of the intensive use of pesticides and mineral fertilizers were applied territorial load and range of index territorial load of pesticides. To assess the environmental significance separate, combined and cumulative impacts of priority anthropogenic co-factors the author carried out predominantly two-factor analysis of variance. The share of influence, correlation coefficient and the Fisher test for each factor separately, but also for its combined and cumulative actions were calculated. It is shown the existence of significant correlation mortality from genital cancer with total territorial load of mineral fertilizers. The more significant the influence of factors on mortality was identified in terms of the total impact of the assortment index territorial load of organo-phosphorus compounds and copper-containing pesticides. It allows to considering them as secondary factors of cancer risk of death for women in rural areas.

Mechanisms of tolerance and high degradation capacity of the herbicide mesotrione by Escherichia coli strain DH5-α.

The intensive use of agrochemicals has played an important role in increasing agricultural production. One of the impacts of agrochemical use has been changes in population structure of soil microbiota. The aim of this work was to analyze the adaptive strategies that bacteria use to overcome oxidative stress caused by mesotrione, which inhibits 4-hydroxyphenylpyruvate dioxygenase. We also examined antioxidative stress systems, saturation changes of lipid membranes, and the capacity of bacteria to degrade mesotrione. Escherichia coli DH5-á was chosen as a non-environmental strain, which is already a model bacterium for studying metabolism and adaptation. The results showed that this bacterium was able to tolerate high doses of the herbicide (10× field rate), and completely degraded mesotrione after 3 h of exposure, as determined by a High Performance Liquid Chromatography. Growth rates in the presence of mesotrione were lower than in the control, prior to the period of degradation, showing toxic effects of this herbicide on bacterial cells. Changes in the saturation of the membrane lipids reduced the damage caused by reactive oxygen species and possibly hindered the entry of xenobiotics in the cell, while activating glutathione-S-transferase enzyme in the antioxidant system and in the metabolizing process of the herbicide. Considering that E. coli DH5-α is a non-environmental strain and it had no previous contact with mesotrione, the defense system found in this strain could be considered non-specific. This bacterium system response may be a general adaptation mechanism by which bacterial strains resist to damage from the presence of herbicides in agricultural soils.

Evaluating the risk of pesticide exposure for amphibian species listed in Annex II of the European Union Habitats Directive

Environmental contaminants like pesticides concern amphibian conservationists. For many European amphibian species, special areas of conservation were created as they are listed in Annex II of the EU Habitats Directive. Agriculture is not prohibited within these conservation areas. In the present study, a risk evaluation at the European level was conducted to identify proportions of land use with regular pesticide applications within the conservation areas and the specific risk of pesticide exposure depending on the species’ biology and ecology. The proportion of agricultural land use and the risk of habitat and individual contamination differ among species but also at national scale. Nearly all species with high risk of habitat pesticide exposure are not threatened within their entire territories and Europe. Conversely, most globally threatened and European priority species are at a lower exposure risk in their habitats – with the exceptions Rana latastei, Pelobates fuscus insubricus, Triturus dobrogicus and Discoglossus jeanneae. In the conservation areas for these species, Habitat Directive management plans need to consider monitoring of habitat contamination with pesticides. Such a monitoring should also be conducted in conservation areas for amphibians that seem to be not threatened yet but are at high exposure risk, e.g. Bombina bombina. Monitoring and conservation action should also take place site-specifically to avoid national or regional loss of amphibian biodiversity. Overall, intensive use of agrochemicals and recent land use changes have the potential to be a serious threat for amphibian species, which can be found within cultivated areas – regardless of their current IUCN status.

The future of smallholders in Latin America: land, food, livelihoods, and the growth of monoculture

Greater investment in agriculture is needed to reduce rural poverty and improve food security; but how investment is made, its context and conditions, is at least as important as how much is invested. This paper presents three case studies of large-scale agricultural investment in Paraguay, Guatemala, and Colombia and shows how monoculture expansion is displacing communities, undermining smallholder livelihoods, and worsening local food security. In some cases displacement is a direct result, when companies acquire land from smallholders. In others it is indirect, when smallholders next to plantations are unable to coexist with the health and environmental problems caused by the intensive use of agrochemicals. Cases also showed how large-scale monoculture expansion is competing for land with small-scale basic food production; thus, households which used to be self-sufficient in food now rely on local markets. Even when companies claim to operate responsibly, their business model determines who bears the r...

An Approach to Orbital Image Classification for the Assessment of Potato Plantation Areas

In the city of Bueno Brandão, South of Minas Gerais State, Brazil, the Watershed of Rio das Antas is located prior to the public water supply and is susceptible to hydro-degradation due to the intensive agricultural activities developed in the area. The potato plantation is the most significant cropping in the city. Because of the possibility of interfering in the preservation areas, mainly the ones surrounding water courses and springs, it is very important to do the assessment of the plantation sites, in order to avoid the risk of water contamination. The procedures adopted by the agro activity farmers generally present the following features: intensive use of agro-chemicals, cropping in places with slopes which are higher than 20%, close to or in permanent preservation areas. The scope of this study was to develop the proper methodology for the assessment of the plantation areas, regarding the short time of procedure, as the period between the plantation and the harvest occurs in six months the furthest. These areas vary year in year out, as the plantation sites often change due to the land degradation. Because of that, geotechnologies are recommended to detect the plantation areas by the use of satellite images and accurate data processing. Considering the availability of LANDSAT medium resolution images, methods for their appropriate classification were approached to provide effective target detection.

Occurrence of agrochemicals in surface waters of shallow soils and steep slopes cropped to tobacco

Tobacco cultivation in shallow soils and steep landscape under intense use of agrochemicals contributes to environment degradation. In this study, we assessed the concentration of agrochemicals in draw wells used for human consumption and a creek in a small catchment predominantly cropped to tobacco. Chlorpyrifos, flumetralin, and iprodione were determined by gas chromatography with electron capture detection, while imidalcloprid, atrazine, simazine, and clomazone were quantified by high-performance liquid chromatography with UV detection. Considering all sampling sites, all agrochemicals were detected at least once, except for flumetralin. The occurrence of agrochemicals in tobacco crops is a consequence of their fast transfer to surface water.

‘Ataulfo’ Mango Flowers Contain a Diversity of Thrips (Thysanoptera)

ABSTRACT ‘Ataulfo’ mango (Mangifera indica L.) is the most popular cultivar of mango to have originated in Mexico. Because of its relatively recent discovery, few studies have been carried out on the best agricultural practices for production of this cultivar, and there is wide variation in methods among growers. Among other aspects, the insect fauna associated with this cultivar has not been formally studied. However, numerous growers spray synthetic insecticides on a regular basis against thrips to reduce populations. The present study was conducted with the main objective of determining the diversity of thrips in Ataulfo mango flowers in Chiapas, Mexico. Two representative orchards were selected: the orchard “Tres-A” characterized by an intensive use of agrochemicals, especially broad-spectrum synthetic insecticides directed against thrips, and the orchard “Rancho La Escondida” that does not spray insecticides. Inflorescences were sampled every five days, from Nov 2008 to Feb 2009. The results confirm ...

Is There a Need for a More Sustainable Agriculture?

In this paper the environmental impact of current agriculture practices is reviewed. Soil loss (along with soil fertility), increasing water demand from agricultural practices and environmental pollution caused by the intensive use of agrochemicals, are among the most pressing issues concerning agriculture sustainability. Biodiversity loss due to land use change and emission of greenhouse gasses from agricultural activities are also causes for concern. A number of alternative agricultural practices are also presented that can help to make agriculture less environmentally damaging by reducing the use of natural resources, limiting inputs and preserving soil fertility and biodiversity. We think that there is room for a different and more ecological agriculture and that research should be implemented in order to better assess the potential and constraints of the different options. However, notwithstanding the great achievements of the “Green Revolution,” the world will need 70 to 100% more food by 2050. So a new challenge lies ahead: how to feed nine billion with less land, water and energy, while at the same time preserving natural resources and soil fertility? Technical advances are important in order to meet the future needs, but addressing key socioeconomic issues, such as the inequality in the access to resources, population growth, and access to education are also a priority if we want to properly deal with sustainability. It may require our society to change some of its paradigms and “values” if we wish to preserve our support system, the soil and its health, for the future generations.