Integrated analytical approaches to assess indicators of the effectiveness of pesticide management practices at a catchment scale


Introduction:

Agriculture is a dominant component of the global economy, and the pressure to produce enough food for the world's ever growing population has had a worldwide impact on agricultural practices. The challenge of securing a sufficient food supply was highlighted in Agenda 21 of the United Nations Conference on Environment and Development in 1992. As a result, the use of fertilizers and pesticides has steadily increased over the years to ensure and sustain high crop yields.
Pesticides can have adverse non-target effects especially in the hydrologic system. Water is the primary pathway by which pesticides are transported from their application areas into the environment. Once pesticides are displaced, they can be widely dispersed into streams, rivers, lakes, reservoirs, and oceans.
Agriculture is both a cause and a victim of water pollution. It is a cause through the discharge of pollutants (pesticides, fertilizers, etc.) to surface and/or groundwater. It is a victim through contaminated water being used for irrigation, for example. The economical, social, environmental and public health implications due to decreasing water quality are a common worldwide threat. Surface waters not only supply a large amount of drinking water to populations, they are also vital aquatic ecosystems that provide important environmental and economic benefits. Fresh water is predicted to become the principal limitation for sustainable development within this century .
Preventing and controlling pollution of water resources, both surface and underground, is a government function that has lead to the adoption of a variety of legislative approaches. Legislation has mainly dealt with the control of "point source" pollution, i.e., pollution that can be tracked to a specific entry point with sufficient accuracy, such as industrial discharges, domestic sewage or municipal wastewater effluents or treatment plants. Reduction of "non-point source" pollution, on the other hand, can be achieved through the application of precautionary measures, including Good Agricultural Practices (GAPs) and through adherence to national requirements on the use and applications of pesticides in the field.
In order to be able to support the control of water pollution, quality data are needed: one can only base management decisions on reliable and scientifically sound measurements. Effective monitoring schemes are necessary to identify specific pollutants, their sources and occurrences, to develop preventive measures, and to assess the efficacy of corrective actions. Developing countries face many problems in establishing appropriate monitoring schemes to evaluate surface water pollution by pesticides, and in producing valid analytical results.
With respect to contaminants in water, the U.S. Geological Survey (USGS) stated that "there is the need for long-term monitoring studies which include a larger number of pesticides and their transformation products". The major difficulty, as pointed out by Ongley (1994) is that "a common observation amongst water quality professionals is that many water quality programmes, especially in developing countries, collect the wrong parameters, from the wrong places, using the wrong substrates and at inappropriate sampling frequencies, and produce data that are often quite unreliable".
Difficulties in developing monitoring schemes arise because pesticide concentrations in surface waters follow strong seasonal patterns that result from the timing of pesticide applications and runoff conditions (rainfall, soil permeability, soil infiltration rate, interflow, etc.). In water, pesticides may be transported as dissolved material or by adhering to suspended matter, such as particulates and sediments. Therefore not only water, but also particulates and sediments, should be considered as part of the research project.
Studies on "non-point source" pollution showed that the primary transfer mechanism from land to water of nutrients, sediments and pesticides is runoff (FAO, 1996); however air drift of pesticides, applied in the fields, can also contaminate streams and waterways.
Rainfall, following a pesticide application in the field, may result in runoff and a pulse of high pesticide concentration continuing downstream until it eventually reaches a lake or a containment area. In lakes or basins, the concentration of stable pesticides are likely to remain elevated much longer than in streams, because the pesticides will not be flushed from the system as quickly, and may be observed for a long time after nearby agricultural applications have been suspended.
The Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia, have developed a "Pesticide Impact Ranking Index" (PIRI) software package to rank pesticides in terms of their relative pollution potential to soils, ground and surface water, and to compare different land uses in catchment areas in terms of their relative impact on water quality. The PIRI software will be used to process data on the application of pesticides in the field to assess the pollution risks to surface and groundwater. Data on concentrations of pesticides gathered through water monitoring will be used to validate the PIRI risk assessments and expand the scope of the software to a variety of agro-ecological zones.
To produce evidence of Good Agricultural Practices, well documented pesticides application records would need to be made available to CRP participants by agricultural extension services or farmers associations. In this respect, FAO through AGP, should be able to help in identifying relevant Stakeholders.
This CRP proposal addresses the use of agrochemicals to provide an adequate and safe food supply whilst ensuring environmental sustainability under the agricultural production system applied. One tool that can be developed through this CRP is to indirectly assess the effects of Good Agricultural Practices used in the field by monitoring pesticide contamination of surface waters.

Objective:

One of the key recommendations from the Food and Environmental Protection Sub-programme's 2005 consultants' meeting on "The Role of Analytical Laboratories in the Application of Good Agricultural Practice (GAP) in the Production of Fresh Fruits and Vegetables and Animals and Animal Products" was to strengthen the capabilities of laboratories and laboratory networks in assessing the implementation of GAP for internal and external markets.
This CRP will contribute to the Joint FAO/IAEA project on "Technologies and Capacity Building to Identify Good Agricultural Practices for the Management of Food and Environmental Hazards" (E3.02) which focuses on the development of principles, indicators and guidelines for agricultural practices that promote food safety and quality and environmental sustainability.
Close linkages will be fostered with activities of the Soil and Water Management and Crop Nutrition Section which is working on tools and approaches to address runoff and erosion at the catchment scale, and is also developing a new program (E.1.08) on "Technologies and practices for efficient agricultural water use and conservation".
The overall objective of this CRP is to help member states develop means of sustainable agricultural development, through the assessment of the effectiveness of GAPs.

Specific objectives are to:

Expected Outcomes:

Expected Outputs:

Activities:

Activity 1: Planning phase

Activity 2: First Research Coordination Meeting (RCM) in Costa Rica from 9-13 July 2007

Activity 3: First experimental period

Activity 4: Second RCM

Activity 5: Second experimental period

Activity 6: Third RCM

Activity 7: Consultants services

Reports:

Project Officer:

B. Maestroni