How it works

1.What can I do with the Environmental Yardstick for Pesticides for field crops?

The Environmental Yardstick is a scoring tool which indicates how harmful a pesticide is for the environment. The tool allows the user to make an informed decision for a crop protection strategy based not only on effectiveness and costs, but also on the side-effects of pesticides on the environment. The Environmental Yardstick for Pesticides can also be used to determine the total environmental impact of all pesticides applied in one season and compare your results to the result of your colleagues.

The indicator calculates and compares the effects of pesticides using five criteria:

risks for water organisms (surface water)
risks for soil organisms
risks for infiltration to groundwater
risks for beneficial organisms (natural enemies and pollinators)
risks for the health of the applicator.

2. Is the Environmental Yardstick for Pesticides adapted to situations in other countries than the Netherlands?

The Environmental Yardstick is developed in the Netherlands, assuming Dutch soil types. To determine the number of Environmental Impact Points (EIP) for aquatic organisms, an average ditch volume is assumed to estimate a pesticide concentration. The same concentration is assumed for all pesticides (0,004 mg/l)

Currently, the Environmental Yardstick for Pesticides is used in an increasing number of countries. When using the Environmental Yardstick outside the Netherlands, the following should be taken into account:

The Environmental Yardstick can be used to make relative comparisons of pesticides only.
To calculate the EIP for aquatic organisms only one emission factor is taken into account: spray drift. In many countries run off is also a (very) important emission route. At the moment we are investigating how this route can be incorportated in the Environmental Yardstick.

3. How many environmental impact points are acceptable?

The environmental effects of pesticides on water organisms, soil organisms and groundwater are scored using so-called environmental impact points (EIP). The more environmental impact points a pesticides scores, the higher the risk the pesticide poses to the environment. Environmental impact points are based on a dose of 1kg/ha of pesticide, and should be multiplied by the actual applied quantity per hectare. For aquatic organisms, soil organisms and groundwater a score of 100 EIP per application is in line with the authorisation standard set by CTGB (The Dutch board for the Authorisation of Plant Protection Products). The authorisation standard is a concentration which poses an acceptable risk to the environment.

4. How are Environmental Impact Points for aquatic organisms calculated ?

The environmental impact on aquatic organisms depends on the toxicity of a pesticide for aquatic organisms. In addition the impact of a pesticide depends on the spray drift to watercourses. The percentage that reaches the watercourses depends on the application technique. Furthermore factors like wind speed, wind direction, crop size, distance to the watercourse, temperature and atmospheric humidity play a part in the amount of drift.

Environmental Yardstick for Pesticides assumes a standard 1% spray drift to surface water (watercourses). Therefore the EIP for aquatic organisms must be multiplied by the actual percentage spray drift of the application technique. For example: Drift is more likely to occur when using a conventional sprayer, compared to using a full-air sprayer or spray application with a untreated bufferzone zone.

Please Note: In 1995 the authorization standard for aquatic organisms has been lowered by a factor 10. Scientific research has showed that a higher safety factor was better (100 instead of 10). As a consequence, the maximum acceptable score was lowered to 10 EIP. As of March 2013, CLM has changed the value back to 100 EIP, in accordance with the standard for soil and aquatic organisms. This means that all EIP for aquatic organisms have been raised with a factor 10.

5. How are Environmental Impact Points for soil organisms calculated?

The Environmental Yardstick for Pesticides takes the organic matter into account. Along with pesticide characteristics such as degradation rate and mobility in soil, organic matter content determines the concentration of pesticides that remains in the soil over the course of time. The pesticide concentration and toxicity together determine the risk that a pesticide poses for soil organisms.

The Environmental Yardstick for Pesticides distinguishes five classes of organic matter content:

less than 1,5% (percentage organic matter)
1,5 - 3%
3 - 6%
6 - 12%
more than 12%

Each soil organic matter content class is assigned a number of Environmental Impact Points (EIP).

Example soil organisms

A farmer uses 0,5 litre/ha Sencor WG as a post-emergence treatment cultivating potatoes. The organic matter content is 5%. In this soil organic matter class, an application of 1 l/ha Sencor WG is assigned 9 EIP.

The total score is:
0,5 kg/ha x 9 = 4,5 EIP

This score is well below the level of 100 EIP, therefore the risk for soil organisms is small.

6. How are Environmental Impact Points for groundwater calculated?

Because organic matter can bind pesticides, organic matter content also determines the risk of leaching of pesticides to the groundwater in most cases. When the organic matter content is high, the risk of leaching is low and less environmental impact points will be assigned.

The lutum content of the soil determines leaching as well, but is of less importance than the organic matter. Pesticide characteristics also determine the degree in which a pesticide leaches to groundwater.

Finally, the amount of environmental impact points for groundwater is dependent on the season of application. The risk of leaching is higher when applying in fall than applying in spring. The reason for this is a slower degradation rate of the pesticide in fall because of low temperatures and the precipitation surplus in this period. In calculating environmental points, the Environmental Yardstick distinguishes between a fall and spring period. These periods are defined as follows:

spring: 1st March - 31st August
fall: 1st September - 29th February

Ofcourse, the boundary between these two periods is arbitrary: Leaching will not be drastically different on the 31st of august when compared to the 1st of September. Differentiating between periods however does serve to show how the impact on groundwater changes during the year. Pesticides have been assigned EIP for each combination of a organic matter content class and a application period.

The boundary between those periods isn’t very strict. For example the leaching of a pesticide applied on the 31st of August isn’t much lower than applied on the 1st of September. The purpose of the periods is to show the variation of the impact on groundwater during the year.

Example groundwater

A farmer uses 1,5 litres/ha Gallant 2000 for weeds in spring. The organic matter content is 3,5%. For this soil organic matter content class and period, 600 EIP are assigned for a dosage of 1 l/ha. The total score for the application of 1,5 l/ha is:

The total score is:
1,5 l/ha x 600 = 900 EIP

This is 9 nine times the acceptable level of 100 EIP, therefore risk for groundwater pollution is high.

7. How are risks for beneficial organisms indicated?

The risk for natural enemies (e.g. ladybirds, predatory mites, hymenopteran parasitoids) and pollinators (e.g. bees and bumblebees) is indicated with a symbol. This symbol shows the usability for integrated cropping systems and is a combination of all pesticide effects for individual beneficial organisms. More detailed information can be found in the Side Effect Guide and internet pages of suppliers of beneficial organisms. The data for the Environmental Yardstick for Pesticides is based on the Side Effect Guide of Koppert Biological systems.

8. How are health risks for professional applicators indicated?

The risk of a pesticide for human health is indicated with a symbol. The symbols are deducted from the symbols (saltire, skull and crossbones) that can be found on the labels of pesticide products.

9. Which environmental effects are most important?

The Environmental Yardstick scores pesticides on six independent criteria. It is the task of the farmer to evaluate which environmental impacts are most important in the context of his own company. For a company adjacent to a lot of watercourses, the risk posed to water organisms may be the most important. For companies in a groundwater protection areas, the EIP score for groundwater risks is very important.

10. Where is the data of the Environmental Yardstick for Pesticides based on?

The data from the Environmental Yardstick for Pesticides are derived from the following sources:

EIP aquatic organisms: CTGB (calculated by CLM)
EIP soil organisms: CTGB (calculated by CLM)
EIP groundwater: CTGB (calculated by CLM)
Beneficial organisms: Side Effect Guide of Koppert Biological Systems

11. How can i determine the spray drift percentage?

The environmental impact on aquatic organisms depends on the toxicity of a pesticide for aquatic organisms. In addition, the impact of a pesticide depends on the spray drift to watercourses. The percentage that reaches the watercourses depends on the application technique. Furthermore factors like wind speed, wind direction, crop size, distance to the watercourse, temperature and atmospheric humidity play a part in the amount of drift.

The Environmental Yardstick for Pesticides assumes a standard 1% spray drift to surface water (watercourses). Therefore the EIP for aquatic organisms must be multiplied by the actual percentage spray drift of the application technique. For example: Drift is more likely to occur when using a conventional sprayer, compared to using a full-air sprayer or spray application with a untreated bufferzone zone.