How it works
- What is the use of the Environmental Yardstick for greenhouse cultivation?
- How are environmental impact points (EIP) calculated for greenhouse cultivation?
- Which EIP score is acceptable?
- Which application methods are included in the Environmental Yardstick?
- How is the Environmental Yardstick applied in practice?
- How are EIP scores exactly calculated?
- Are recent developments in research inlcuded in the Environmental Yardstick?
The Environmental Yardstick is a tool to compare environmental harmfulness of pesticides. By comparing the environmental impact points (EIP) of pesticides, the least harmful pesticide can be chosen. The Environmental Yardstick can also be used to determine the total environmental impact of all pesticides used during a season, and this impact can be compared with collegues. The environmental impact for greenhouse cultivation is measured in environmental impact points (EIP). The more harmful the pesticide is, the higher the EIP score. The EIP gives an indication of the environmental impact compared to other pesticides.
This yardstick is meant only for greenhouse cultivation. Information about the environmental impact of pesticides used in field crops can be found in the Environmental Yardstick for Pesticides in field crops.
The volatility, degradation, toxicity, the application technique and the actual applied quantity are taken into account in the calculation of the environmental impact points (EIP). For example, a pesticide that is highly toxic and vaporizes quickly will have a higher EIP than a pesticide that is only slightly toxic. Pesticides applied as space treatment will usually have a higher EIP than pesticides that are sprayed. The EIP score indicates the risk of a pesticide to aquatic organisms outside the greenhouse. It appears that the use of pesticides in greenhouse cultivation is most harmful to aquatic organisms. The EIP does not estimate health risks for the applicator. For more information, see question 6.
In contrast to the Environmental Yardstick for field crops, the Environmental Yardstick for greenhouse cultivation does not define an acceptable EIP score. Because the Dutch government, in its policy for the authorization of pesticides, has not yet defined acceptable levels for pesticide emissions by air, no acceptable norm can be defined. However, by comparing the environmental impact of authorized pesticides, it is possible to inlcude environmental impact as a criterium in the choice for a crop protection strategy. The EIP for greenhouse cultivation can not be compared with the EIP for field crops.
The emission (evaporation) of pesticides is higher when applied as a space treatment when compared to other methods. Therefore, the Environmental Impact Point score of a pesticide applied as space treatment will be higher than the same pesticide applied using a differen method. The Environmental Yardstick takes this difference in account by assigning differen EIP's per application method per pesticide.
The following application methods are supported:
LVM, fogging (Pulsfog, Dynafog and Swingfog), pesticide smoke, spraying, dusting, sulfur evaporation
Colfogging, crop specific spraying (motorized backpack spraying, spray robot, cage sprayers), electrostatic spraying, spray boom, spray lance, spray gun, granulates, spot treatment and soil application
From an environmental viewpoint it is important to avoid the use of harmful pesticides. For some reasons, such as economical reasons, harmful pesticides might remain necessary. For instance, a pesticide with a low overall environmental impact might have a more adverse effect on a biological controller when compared to a pesticide with a higher overall environmental impact. To maintain biological control, the pesticide with a higher environmental impact may be the better choice. For information on the effects of pesticides on biological controllers we refer to the Side Effect Guide of biological controller suppliers. Furthermore, when a pesticide is used multiple times in succession, the pest pupulation may develop resistance against the pesticide. Although using pesticides of different chemical groups may prevent the development of resistance, a sustainable crop protection strategy also includes prevention of pests and diseases by, for instance, resistant crops or climate control. Additionally, the use of biological controllers has potential, especially in floriculture. Currently, the environmental impact score on the Environmental Yardstick does not include the impact on the health of applicators. For safe application of the pesticides, farmers are referred to standard information sources such as product labels and application guides.
For each pesticide authorized for greenhouse cultivation Environmental Yardstick for Pesticides calculates a score. In this section we explain how these scores have been calculated.
Emission pathways and environmental impact
After application, pesticides may enter the environment through a number of pathways. The main pathways are by air, condensated water and drainage. In the case of crops cultivated directly in the soil, pesticides may also enter the environment through groundwater and surface water. In the Netherlands, these emission pathways are adressed in the Law on Pollution of Surface Waters, and as such are not included in the Environmental Yardstick for Greenhouse cultivation. Emission and diffusion of pesticides through the air is an important pathway into the environment. This pathway is used to calculate environmental impact. For in-soil cultivation, soil and groundwater pathways are important as well. However, the environmental impact score for these pathways does not differ from the score for emssions by air. For this reason, no separate environmental impact factor has been inlcuded for these pathways.
Two factors are important in calculating the environmental impact of pesticides:
- In what quantity does the substance enter the environment?
- What is environmental risk of the active substance?
These questions are answered in more detail below.
The quantity entering the environment
Emission by air plays a role in both in-soil and substrate greenhouse cultivation. Emissions depend on volatility of the pesticide and application technique. Emissions vary between less than 1% up to 40% of the actual applied quantity. After evoprating from the greenhouse (through narrow openings or by ventilation) some time will elapse before the substance is deposited. During transport, part of the pesticide will broken down, the remaining pesticide may pose a risk to the environment.
it takes a while before the pesticide reaches surface water. A part of the pesticide will be broken down during transport. The remaining part can pose a risk to the environment.
Calculation of the environmental impact of the active substance
The amount of the pesticide that evaporates from a greenhouse can pose a risk to organisms nearby. Research proved that aquatic organisms are at the highest risk. The level of toxicity for this group of organisms is used to calculate the Environmental Yardstick score. The Maximum Permissible Concentration (MPC) for aquatic organisms, the pesticide concentration in water at which 95% of the species in aquatic ecosystems show no harmful effects, is used to determine the level of toxicity.
Calculation of the environmental Impact points per pesticide product
The environmental impact points are calculated as follows: The amount of active substance remaining 12 hours after application is devided by the MPC for water organisms. This score is a relative value for the environmental risk. The score allows for comparison of different pesticides. For each active substance authorized for greenhouse cultivation a score has been calculated. These scores have been used to calculate a total score for commercially available pesticides common in greenhouse cultivation. These scores, combined with the actual applied amount, provide the information to calculate the environmental impact of pesticides as explained in this example.
In recent years, more and more reports on pesticide emissions form greenhouse cultiviation have been published. Depending on circumstances, emission pathways other than by air may be important. CLM is investigating how to incorporate these findings in the Environmental Yardstick.