Activities in nonpoint pollution control in rural areas of Poland

Agriculture can contribute to water quality deterioration through the release of sediments, pesticides, animal manure, fertilisers and other sources of inorganic and organic matter. Nonpoint pollution control activities in rural areas of Poland are insufficient to meet the demands of the recovering agricultural production. There is still a need for agricultural runoff monitoring programs for identification, quantification and control of nonpoint sources. Special efforts are required to familiarise farmers with environmental friendly agricultural production technologies and ‘good agricultural practices’. This paper describes typical nonpoint sources from Polish agriculture. It presents all these activities and achievement in nonpoint pollution control after 1989, when systemic changes began and environmental problems became more visible.     

Plant protection and growth stimulation by microorganisms: biotechnological applications of Bacilli in agriculture

The increasing demand for a steady, healthy food supply requires an efficient control of the major pests and plant diseases. Current management practices are based largely on the application of synthetic pesticides. The excessive use of agrochemicals has caused serious environmental and health problems. Therefore, there is a growing demand for new and safer methods to replace or at least supplement the existing control strategies. Biological control, that is, the use of natural antagonists to combat pests or plant diseases has emerged as a promising alternative to chemical pesticides. The Bacilli offer a number of advantages for their application in agricultural biotechnology. Several Bacillus-based products have been marketed as microbial pesticides, fungicides or fertilisers. Bacillus-based biopesticides are widely used in conventional agriculture, by contrast, implementation of Bacillus-based biofungicides and biofertilizers is still a pending issue.     

Effets sur le spermatozoïde humain du Diuron (3-(3,4-dichlorophényl)-1,1-diméthyl-urée) et de l’un de ses produits de transformation, la 3,4-dichloroaniline (3,4-DCA) (Etude préliminaire)

Diuron belongs to the family of halogenophenylureas, one of the main groups of herbicides used for more than 40 years. These herbicides absorb sunlight and can be photochemically transformed in the environment (herbicides are transformed on the soil surface exposed to sunlight) or biotransformed by microorganisms present in soil or in water. The metabolites (chlorohydroxyphenylurea, chlorophenylaniline, respectively) are more toxic than the parent compound, as demonstrated by a bioluminescence inhibition assay performed with a marine bacterium (Vibrio fischeri toxicity test). The lipophilicity of these pesticides makes the cell membrane a target for their action, especially the spermatozoa cell membrane. The aim of this study is to use human spermatozoa to evaluate the effect of this urea pesticide and its biotransformed product on the spermatozoa membrane. We investigated the structural and functional effects of these environmental pollutants on spermatozoa. Three million spermatozoa purified on a 95/47.5% Percoll gradient were suspended in 250 μl of modified Earle’s medium (without phenol red) supplemented with 7.5% of human decomplemented serum. Pesticides (Diuron or 3,4-dichloroaniline (3,4-DCA)) were added at a final concentration of 0.1; 1 and 5 mM. Samples were incubated at room temperature for 24 hours. We show that both Diuron and 3,4-DCA decrease motility and vitality of spermatozoa incubated with the highest concentration of pesticides. Our preliminary results show that the effects are more rapid and more intense with the biotransformed product (3,4-DCA) than with Diuron. Addition of herbicide to human spermatozoa increases membrane fluidity, assessed by measuring the fluorescence polarisation anisotropy with a fluorescent probe: 1,6-diphenyl-1,3,5-hexatriene (DPH). Changes in membrane fluidity may be a primary toxic effect of these herbicides. These results suggest that human spermatozoa may constitute a valuable indicator of the toxic effects of pesticides.     

Fatty acid profiling as bioindicator of chemical stress in marine organisms: A review

The development of industrial, anthropogenic, and agricultural activities is the main factor leading to contaminants’ increasing in marine ecosystems. Contaminants include the great variety of pesticides and heavy metal pollutants. One of the major environmental concerns about herbicides and heavy metals contamination is their bioaccumulation in the ecosystem's primary producers and its subsequent propagation through the trophic chain. Over the last decades, the use of biochemical markers considerably contributed to the evaluation of contamination hazards. The fatty acid composition proved to be a good bioindicator to assess contamination levels. This paper provides a review of current knowledge on the fatty acids response in marine species after exposure to the chemical stressors including organic and inorganic pollutants, mainly pesticides and heavy metals. This review underlines the consistent directional trends in changes of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids, and summarizes the mechanisms of action leading to their alteration and possible consequences of these changes to marine species from different trophic levels.     

我国主粮作物的化学农药用量及其温室气体排放估算

现代农业中化学农药在提高作物产量中发挥着重要的作用,但是我国普遍存在过量用药现象,导致环境污染和危害食品安全.基于2012年的全国性农户问卷调查,本研究分析了2011年我国水稻、小麦和玉米使用农药现状,并估算了它们的温室气体排放.结果表明: 这3种作物至少使用了54种杀虫剂、24种杀菌剂和50种除草剂,其中32%的水稻种植农户使用了生物农药.全国3种作物使用了30.8 kt杀虫剂、16.5 kt杀菌剂和58.3 kt除草剂,它们的温室气体排放总量为1.5 Tg Ce,杀虫剂、杀菌剂和除草剂的排放分别占23.8%、16.9%和59.3%.南方区的农药用量占全国用量的51%;全国水稻、小麦和玉米的单位产量农药用量分别是0.22、0.18和0.24 g·kg^-1粮食,3种作物用药总量分别为44.4、21.4和39.7 kt,温室气体排放分别为665.5、250.1和547.5 Gg Ce;在不同农药种类中,有机磷类杀虫剂占我国所用杀虫剂总量的69%,苯丙咪唑类、有机磷类、唑类和有机硫类等杀菌剂占杀菌剂总量的87%,酰胺类、有机杂环类和有机磷类等除草剂占除草剂总量的85%.因此,减少农药用量,对于我国粮食安全和环境安全及减少农业温室气体排放都具有重要意义.     

Über den Einfluss der Herbizide auf einige Süsswassertiere

Toxicity of fourteen herbicides has been determined for thirteen animal species: Planaria gonocephala, Tubifex sp., Lymnaea stagnalis, Daphnia pulex, Gammarus pulex, Asellus aquaticus, Micronecta minutissima, Esox lucius, Cyprinus carpio, Phoxinus phoxinus. Leucaspius delineatus, Perca fluviatilis, Rana temporaria, in 510 laboratory experiments. It was followed in three concentrations and expressed both in tables, by the value LT₅₀ or by the various degree of damage of the organisms, and in graphs. The organisms were divided into four groups according to their sensitivity to herbicides: 1. organisms with high sensitivity; 2. sensitive; 3. medium sensitive; 4. little sensitive. From the point of view of the toxicity the herbicides were divided into three groups: 1. powerfully toxic; 2. medium toxic; 3. little toxic. A relationship between the intensity of toxicity and the chemical structure of herbicides was found. The first group includes herbicides on the basis of carbamates and phenols, the second group includes the derivates of phenoxyacetic acid, and the third group includes inorganic herbicides and those pertaining to the group of the chlorated organic substances. The mechanism of the toxic action was followed from the point of view of the mutual relationship of herbicide toxicity and the sensitivity of organisms. Eight basic types of this action were found. Special attention was paid to those types where significant reparation phases appeared during the experiments. Only inorganic herbicides and those from the group of the chlorated organic substances or eventually those on the basis of phenoxyacetic acid may be used for mass application in water economy. In all cases further complex investigations must be made concerning the influence on water biocenoses, as the recent data on the toxicity of herbicides with respect to several species of fish only are not sufficient. The use of herbicides from the group of phenols and carbamates should be prohibited in the neighbourhood of water bodies.     

The paucity of plants evolving genetic resistance to herbicides: Possible reasons and implications

Resistances to antibiotics and pesticides except herbicides rapidly developed following their introduction. Despite repeated use of herbicides only a few cases of acquired genetic resistance have been reported. By extrapolation from analogous situations, it is suggested that this is due to a combination of low selection pressure of most herbicides, lower fitness of resistant weed strains in the absence of herbicide, the ability of herbicide thinned strands of susceptible weeds to produce relatively more seeds, as well as to the large soil reservoir of susceptible weed seeds. The few reported cases of resistance are to persistent, high selection pressure herbicides supporting our contentions.     

Towards the sustainability of the Lake Naivasha Ramsar site and its catchment

Sustainable development remains a pressing priority for the Lake Naivasha Ramsar site, as a matter both of long-term protection of the lake ecosystem and of the economic and social progress that depends upon it. This must be addressed at catchment-scale to protect the `ecosystem services' that constitute the region's primary resources. Sustainability principles highlight energy, fertilisers, pesticides and other aspects of chemical use, plastics, erosion and sedimentation, wildlife, water and socio-economic issues as central to sustainable development strategy, influenced by both intensive and subsistence farms across the catchment. Market forces and long-term self-interest provide compelling arguments for sustainable development, the delivery of which will depend upon education and the spreading of good practice, perhaps backed up by stewardship schemes. Alternatively, the adverse consequences of continued unsustainable practice are highly significant for the region.     

Effects of organic and inorganic fertilisers on mosquito populations in rice fields of southern India

The effects of nitrogenous (inorganic) fertilisers, organic manures and blue-green algae (BGA) biofertiliser on mosquito populations (Diptera: Culicidae) were studied in rice fields of Madurai, Tamil Nadu, south India, with particular attention to Culex vishnui Theobald, Cx. pseudovishnui Colless and Cx. tritaeniorhynchus Giles, the vectors of Japanese encephalitis (JE). The application of urea, a nitrogenous fertiliser, in rice fields significantly increased the grain yield and the population densities of mosquito larvae and pupae (anophelines as well as culicines) in a dose-related manner. Fields treated with inorganic fertilisers (N, P, K) had significantly higher population densities of mosquito immatures than fields treated with organic manures (farmyard manure and green manure). Without nitrogenous fertiliser, BGA increased paddy yield without enhancing mosquito production. Therefore, the use of BGA with less nitrogenous fertiliser is recommended, which is beneficial economically and agronomically to the farming community and also significantly reduces mosquito production in rice fields. Increased use of nitrogenous fertiliser over the past two decades may have contributed to the increased severity of Japanese encephalitis epidemics, vectors of which breed in rice fields.     

Effect of land use on pollution status and risk of fish endocrine disruption in small farmland ponds

To study whether the intensity of agricultural activities affects pesticides loads in pond environment, a large number of Belgian farmland ponds were surveyed in spring 2004. Temporal distribution of pollutants was also investigated over restricted survey ponds sampled three times round year 2007. Sedentary pond Prussian carp juveniles were also captured to determine their brain aromatase activity (AA) and plasma vitellogenin (VTG) levels. Heavy metal distribution was also examined in various pond matrices. Amongst the pesticides analysed, only herbicides were detected. Contamination of pond water by atrazine was frequently observed during spring 2004, while isoproturon and glyphosate were detected round year 2007. Levels of herbicides were inversely related to the distance of ponds to crop field, and values peaked in April or October. Absence of endocrine disruptors in pond water was confirmed by lack of modulation in VTG and AA in male fish. Heavy metals were present in all the pond matrices, but overall contamination levels were low. The results demonstrated that Belgian ponds were mainly contaminated by herbicides and that pond sedentary fish were not affected by endocrine disruptors. They also demonstrated a marked effect of land-use intensity on herbicide pollution which can be mitigated by an adjustment of the buffer zones.     

Helping farmers to reduce herbicide environmental impacts

While pesticides help to effectively control crop pests, their collateral effects often harm the environment. On the French island of Reunion in the Indian Ocean, over 75% of the pesticides used are herbicides and they are regularly detected in water. Agri-environmental models and pesticide risk indicators can be used to predict and to help pesticide users to reduce environmental impacts. However, while the complexity of models often limits their use to the field of research, pesticide risk indicators, which are easier to implement, do not explicitly identify the technical levers that farmers can act upon to limit such transfers on their scale of action (the field). The aim of this article is to contribute to developing a decision support tool to guide farmers in implementing relevant practices regarding the reduction of pesticide transfers. In this article, we propose a methodology based on classification and regression trees. We applied our methodology to a pesticide risk indicator (I-PHY indicator) for identifying the importance of the variables, their interactions and relative weight in contributing to the score of the indicator. We applied our methodology to the assessment of transfer risks linked to the use of 20 herbicides applied to all soils in Reunion and according to different climate, plot management and product application scenarios (4096 scenarios tested). We constructed regression trees which identified, for each herbicide on each soil type, the contribution made by each input variable to the construction of the indicator score. The tree is represented graphically, and this aids exploration and understanding. The 20 herbicides were divided into 3 groups that differed through the main contributing variable to the indicator score. These variables were all technical levers available to farmers to limit transfer risks. These trees then become decision support tools specific to each pesticide user, enabling them to take appropriate decisions with a view to reducing pesticide environmental impacts.     

利用人工湿地去除农业径流中农药的研究进展

人工湿地对农业径流污染物去除效果显著,已成为控制农业径流污染的有效措施.本文结合国内外研究,介绍了当前水体农药污染的现状;从物理、化学及生物角度阐述了人工湿地对农药的去除机理和关键过程;归纳总结了人工湿地对农药的去除效率,指出人工湿地对农药的去除效率随农药类型的不同而差异较大:农药的平均去除率,按农药用途分为杀虫剂＞杀菌剂＞除草剂,按农药化学结构分为拟除虫菊酯类>有机磷类>三唑类＞酰胺类＞三嗪类＞脲类;综合考虑,潜流人工湿地在农药去除方面的效果优于表面流人工湿地.在此基础上分析了农药理化性质、人工湿地工艺类型及运行参数、进水中农药浓度、湿地植物等因素对农药在人工湿地中去除的影响.最后指出了当前研究中存在的问题,并提出了研究展望.     

Ovicidal activity of Couroupita guianensis (Aubl.) against cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

There is a great demand for food with increasing population of the world. Many chemical fertilisers and pesticides are used to increase crop productivity. Over use of pesticides and fertilisers has affected the environment and non-target organisms severely; minor pests have become major destructive pests. Hence, eco-friendly approaches are needed. The present study reports the effect of hexane, chloroform and ethyl acetate extract of Couroupita guianensis on the eggs of Helicoverpa armigera. All the extracts showed ovicidal activity, and among them hexane extract showed 64.28% ovicidal activity with LC₅₀ value of 2.62% and regression of (R ²) 83.5%. All the original data showed normality and homogeneity. The active hexane extract was fractionated; finally, eight fractions were obtained and studied at different concentrations. Among the fractions, fraction 8 showed 75% ovicidal activity with R ² of 90%. It showed LC₅₀ value of 322.94?ppm with χ ² value at 0.5%. C. guianensis could be used in pest management programme.     

Results of the fifth joint pesticide testing programme carried out by the IOBC/WPRS-Working Group “Pesticides and beneficial organisms”

Laboratory, semi field and field tests to assess the side effects of 20 pesticides on 19 different beneficial organisms were carried out by members of the Working Group “Pesticides and Beneficial Organisms” of the International Organization for Biological Control (IOBC), West Palearctic Regional Section (WPRS). This 5^th joint pesticide testing programme of the working group was carried out by 21 participants in 11 European countries. The pesticides (7 insecticides, 8 fungicides and 5 herbicides), that were chosen for their possible selectivity, were tested according to internationally approved principles. Among the 20 preparations tested, the insecticides Apollo SOSC, Cesar S.L., the fungicides Baycor, Delan flüssig, Vitigran, Impact, Rovral PM, and the herbicides Luxan 2,4-D amine, Ally and Dirigol-N were harmless to nearly all the beneficial organisms tested and are recommended for use in integrated control programmes. The further testing of the remaining 10 preparations is recommended. The activities of the working group to complete the development of urgently needed sequential procedure to test the side effects of pesticides on beneficial organisms based on standard laboratory, semi field and field methods and the need for more international cooperation are discussed.      

Vegetated Ditches for the Mitigation of Pesticides Runoff in the Po Valley

In intensive agricultural systems runoff is one of the major potential diffuse pollution pathways for pesticides and poses a risk to surface water. Ditches are common in the Po Valley and can potentially provide runoff mitigation for the protection of watercourses. The effectiveness depends on ditch characteristics, so there is an urgent need for site-specific field trials. The use of a fugacity model (multimedia model) can allows recognition of the mitigation main processes. A field experiment was conducted in order to evaluate the mitigation capacity of a typical vegetated ditch, and results were compared with predictions by a fugacity model. To evaluate herbicide mitigation after an extreme runoff, the ditch was flooded with water containing mesotrione, S-metolachlor and terbuthylazine. Two other subsequent floods with uncontaminated water were applied 27 and 82 days later to evaluate herbicides release. Results show that the ditch can immediately reduce runoff concentration of herbicides by at least 50% even in extreme flooding conditions. The half-distances were about 250 m. As a general rule, a runoff of 1 mm from 5 ha is mitigated by 99% in 100 m of vegetated ditch. Herbicides retention in the vegetated ditch was reversible, and the second flood mobilized 0.03-0.2% of the previous one, with a concentration below the drinking water limit of 0.1 μg L^-1. No herbicide was detected in the third flood, because the residual amount in the ditch was too low. Fugacity model results show that specific physical-chemical parameters may be used and a specific soil-sediment-plant compartment included for modelling herbicides behaviour in a vegetated ditch, and confirm that accumulation is low or negligible for herbicides with a half-life of 40 days or less. Shallow vegetated ditches can thus be included in a general agri-environment scheme for the mitigation of pesticides runoff together with wetlands and linear buffer strips. These structures are present in the landscape, and their environmental role can be exploited by proper management.     

Denitrifying capacity of rhizobial strains of Argentine soils and herbicide sensitivity

Agrochemical application in soils is a matter of environmental concern, and among soil microorganisms, rhizobia and their action before different pesticides are interesting to study, due to their taxonomic and functional diversity. The objectives of the present work were to assess the capacity of rhizobial populations to use herbicides as source of nutrients, as well as their ability to reduce nitrates and / or denitrify. Eighty-one strains belonging to four populations of different genera of rhizobia (Rhizobium, Mesorhizobium, Ensifer and Bradyrhizobium) were assessed. The effect of glyphosate, 2,4-dichlorophenoxyacetic acid, and atrazine on growth of the strains, as well as the ability of the strains to act on herbicide transformation to reduce nitrate and denitrify, were evaluated. The genera studied showed different responses to pesticides. Bradyrhizobium had the greater capacity to utilize the herbicides and among the compounds evaluated, atrazine was the most used as a source of energy. To conclude, some Bradyrhizobium strains were able both to denitrify and to use the atrazine herbicide. The results obtained in this study increase expectations of the use of rhizobia as inoculants, causing changes at the agricultural and environmental level and allowing an appropriate management of agricultural soil fertilization, efficiency in nitrogen fixation and a faster biodegradation of pesticides in soil.     

The susceptibility and resistance of fry and fingerlings of Oreochromis mossambicus Peters to some pesticides commonly used in Sri Lanka

The acute toxicity (48 hr LC₅₀) of seven herbicides, three acaricides and eight insecticides used in the Control of agricultural pests in Sri Lanka to the fry and fingerlings of Oreochromis mossambicus Peters were investigated in freshwater at 28–29°C under static laboratory conditions. The fry were more susceptible to the pesticides tested than were the fingerlings. Most of the pesticides tested induced severe behavioural changes in the exposed fish. Exposure to some herbicides and insecticides resulted in lateral and upward bending of the body, while higher concentrations of some pesticides caused excessive mucous secretions, rupturing of eyes and production of haemmorrhagic patches. Of the pesticides tested on fry and fingerlings, Ronstrar, Elsan and Endosulfan are the most toxic herbicide, acaricide and insecticide, respectively, while Basfapon, Rogor and Azodrin 60 are, respectively, the least toxic herbicide, acaricide and insecticide.     

生物传感器在环境分析中的研究现状与前景

在环境控制中,生物传感器作为广谱装置应用于废水或生化需氧量的检测,特异性地对农药、重金属、硝酸盐、亚硝酸盐、除草剂和次氮基乙酸等环境污染物进行检测。讨论了各类生物传感器（酶生物传感器、全细胞生物传感器、受本传感器和免疫传感器）在环境分析中的应用实例及其优缺点,并指出了急需解决的问题以阐明其应用趋势。     

Sustainable agriculture: how to sustain a production system in a changing environment

During the past 10-15 years, sustainable agriculture has progressed from a focus primarily on a low-input, organic farming approach with a major emphasis on small fruit or vegetable production farms, often described as Low Input Sustainable Agriculture, to the current situation where sustainability is an important part of mainstream animal and plant production units. The US Department of Agriculture programmes cover a broad range of activities, including conserving the natural resource base, enhancing environmental quality, and sustaining productivity of the nation's farms. The use of Geographic Information Systems technology to direct application of fertilisers, pesticides, and herbicides is one example of a rapidly emerging technology that can reduce use of external inputs, protect the agricultural environment, and improve economic returns. This Geographic Information Systems technology also is being used to localise animal pest and disease problems, assist in regulatory or control measures, and identify high risk areas that might need different management systems or should be avoided as sites for animal production. Use of intensive grazing systems also has increased markedly over the past 5-6 years. These systems will allow longer grazing seasons in southern parts of the USA, provide more efficient use of the forages being produced and reduce labour costs in the typical dairy operation. Major animal and plant production agriculture-oriented programmes at the US Department of Agriculture focus on integrated production systems, use of Integrated Pest Management techniques, and development of alternative methods to manage pests and diseases that reduce or avoid the use of drugs and chemicals. The US Department of Agriculture has a programme for sustainable agriculture, the Sustainable Agriculture Research and Education programme, which emphasises alternative approaches for animal and plant production systems.     

A novel biosensor selective for organoarsenicals

Organoarsenicals used as herbicides and growth promoters for farm animals are degraded to inorganic arsenic. Available bacterial whole-cell biosensors detect only inorganic arsenic. We report a biosensor selective for the trivalent organoarsenicals methylarsenite and phenylarsenite over inorganic arsenite. This sensor may be useful for detecting degradation of arsenic-containing herbicides and growth promoters.