|Main authors:||R.K. Laursen, F. Bondgaard, P. Schipper, K. Verloop, L. Tendler, R. Cassidy, L. Farrow, D. Doody, F. A. Nicholson, J. R. Williams, I. Wright, J. Rowbottom, I. A. Leitão, A. Ferreira, B. Hasler, M. Glavan, A. Jamsek, N. Surdyk, J. van Vliet, P. Leendertse, M. Hoogendoorn and L. Jackson-Blake.|
|Source document:||»R.K. Laursen et al. (2019) Evaluation of Decision Supports Tools. FAIRWAY Project Deliverable 5.2 216 pp|
A comprehensive review and survey of Decision Support Tools (DSTs) currently in use in the FAIRWAY case studies is described in »Survey and review of existing decision support tools. Of the 36 DSTs identified as most relevant, 12 were selected for further investigation to see if a tool developed in a particular national context could be used or provide inspiration elsewhere (»Evaluation of decision support tools). Here we describe the tools evaluated for potential use in the Aalborg case study.
|1. Selection of DSTs for evaluation in the Aalborg case study|
|2. Environmental Yardstick for Pesticides|
|[Note: Because of the resolution of the images, it is difficult to see the detail in some of the figures and tables. See the »full report for more legible originals.]|
In Denmark, farmers are only allowed to use pesticides approved by the Danish Environmental Protection Agency. The chemical agents are tested in the Danish Pesticide Leaching Assessment Programme to provide an early warning of the risk of groundwater contamination when approved pesticides are used in accordance with current regulations. If a pesticide or its degradation products leach to the groundwater, the monitoring results generated by the programme provide a basis for reassessment of the substance by the Danish Environmental Protection Agency.
The FAIRWAY case study site at Aalborg is located in one of the most vulnerable areas in Denmark with regards to nitrate and pesticide leaching to groundwater (»Aalborg case study description). In Denmark, the DSTs Mark Online and Plant Protection Online are available to support sustainable nutrient and pesticide management at the farm level and are operated within Danish legislative requirements. Thus, it is assumed that these DSTs improve the efficient use of nitrogen and pesticides and by that improve water quality.
Based on the findings summarised in evaluation scheme 0 (see Appendix in the »full report), it was found that the Dutch DST Environmental Yardstick for Pesticides and the French DST SIRIS do the same with regard to pesticide management in the countries for which they were developed. These DSTs were therefore tested and assessed in a Danish context and compared to Danish pesticide tax system, which reflect the risk of the pesticides. Additionally, the Danish DST TargetEconN was tested to assess how to apply N mitigation measures and where to apply them, to minimize the costs of meeting a nutrient load reduction target (the WFD targets are currently considered). The testing of TargetEconN is continued in »Assessments of costs and benefits using decision support tools.
Environmental Yardstick for Pesticides is a Dutch DST applied to quantify the environmental impact of the use of pesticides. For each permitted pesticide in the Netherlands, the Environmental Yardstick for Pesticides assigns environmental impact points (EIP) at the recommended product dose per ha to express the risk to water organisms, the risk of leaching to groundwater and the risk to soil organisms. High EIP (i.e. >1000 EIP) means high risk for the environment and this shows up as red in the Environmental Yardstick for Pesticides. A score of 100 – 1000 EIP shows up as orange and means medium risk, and low risk is green and has 0 – 100 EIP. Based on the EIP, the user can compare agents and choose the least harmful crop protection strategy.
In Denmark, to reduce the use of pesticides, DSTs such as Plant Protection Online and the Agent Database combined with the field experiments in the Nordic Field Trial System (NFTS) form the basis of recommendations to local advisors in relation to the composition of the weeds to be controlled. Agricultural advisors making field visits to farms in the growth season to help evaluate the correct dose are also important.
In winter cereals, a low dose strategy is based on knowledge of the composition of the weed population and early control. Often the weed will be controlled before germination or just after emergence at a very early stage, which requires in depth knowledge of the weed composition at field level. Often, very broad-spectrum spraying agents are used. The farmers and the advisors enter into Plant Protection Online and they fill in their experiences on the weed composition in the current field and the program calculates which pesticides are most effective to use. Based on this Plant Protection Online is a useful DST for advisors and farmers to make the right decisions. Testing the Environmental Yardstick for Pesticides in a Danish context is therefore an interesting exercise.
Results of the tests with approved Danish pesticides in maize, potatoes and winter wheat using the Environmental Yardstick for Pesticides are presented in the following sections.
In the Netherlands, there are 72 different products approved for control of weeds in maize. In comparison, Denmark only have 5 of the approved products available: Callisto, MaisTer, Harmony SX, Starane 333 HL and Fighter 480. These 5 products have been tested using the Environmental Yardstick for Pesticides (Figure 2). The results show that it is better to use the herbicide Callisto in maize than MaisTer, with respect to pesticide leaching to groundwater.
Callisto, MaisTer, Harmony SX, Starane Top (DK Starane 333 HL) and Basagran (DK Fighter 480) are all the same only with different names.
However, in Denmark farmers often use a combination of 2-3 products. As an example, cranesbill (in Danish: storkenæb) is often a problem in maize and requires a combination of herbicides. Callisto and MaisTer have a low effect on Cranesbill (Table 6), so MaisTer, Callisto and Fighter 480 are used in a combination (Table 7). Therefore, a typical strategy for weed control in Denmark is to mix products in order to control different weed species (Table 7).
The test in maize shows that the Environmental Yardstick for Pesticides is not able to provide advice on which weeds are controlled by which products. This makes the tool less useful at field level. In Denmark, the dose recommended by the producer is not used. Instead lower combination doses based on field trials are used in order to control the exact composition of the weed species (Table 7).
As with maize, the availability of herbicides used on potatoes in Denmark is very limited (Figure 3) in comparison to the Netherlands, where 47 different products are available for potatoes. Additionally, the products are used in very different ways, which makes the Environmental Yardstick for Pesticides not relevant. Because only a few herbicides are available and because they have different effects, this means that there is no need for a DST, which can separate the risk. Only if there are more than 5 pesticides with nearly the same effects does it make sense to use the Environmental Yardstick for Pesticides.
From 2020 Denmark will not be allowed to use Reglone anymore.
In winter wheat, the recommendations are often complicated because low dose mixtures are often used to ensure high effect and prevent herbicide and fungicide resistance in Denmark. Figure 4 shows the results from the Environmental Yardstick for Pesticides tested with approved Danish pesticides in winter wheat.
Often mixed products and a split application strategy are used in winter wheat fields. A combination of herbicides in winter wheat are often recommended. Table 9 shows the SEGES Strategy for control of different weed species in winter wheat with herbicides.
The Environmental Yardstick for Pesticides focuses on leaching of pesticides to groundwater, and the DST’s strength is risk management of pesticides. This is useful if the purpose is to select the most sustainable products from a wide selection. Generally, the Netherlands have more products available for the control of weeds in maize, potatoes and winter than Denmark. Thus, the Environmental Yardstick for Pesticides is much more relevant in the Netherlands than in Denmark. A combination of the Environmental Yardstick for Pesticides and the Danish DST Plant Protection Online would be a useful DST. To prevent resistance development, it is crucial to use many different products with different mechanisms of action, and this requires the use of complex DSTs.
The Danish DST Plant Protection Online does not visually display the risk effect. In Denmark the risk is controlled by taxes on pesticides, so a high risk means high taxes. The tax is calculated based on factors such as health, environmental behaviour and environmental effect.
SIRIS is a French DST mainly used by the administration to refine pesticide surveillance programmes. In SIRIS, “Le-rang” defines the risk. A high “Le-rang”-percentage means a high risk of pesticide leaching. SIRIS does not differentiate risks between spring and autumn applications, as does the Dutch DST Environmental Yardstick for Pesticides. However, the leaching potential in SIRIS takes into consideration the organic matter in soil.
SIRIS has, as with the Environmental Yardstick for Pesticides, been tested with pesticides approved in Denmark for application in maize, potatoes and winter wheat.
In the following, the results of a comparison of SIRIS, Environmental Yardstick and the Danish pesticide tax system is presented. The test was based on the expectation that there is the same level of risk for leaching in all countries for each pesticide.
Comparison of SIRIS, Environmental Yardstick for Pesticides and the Danish pesticide tax system
SIRIS and the Environmental Yardstick for Pesticides were developed to test the risk of pesticide leaching to the groundwater. In Denmark, pesticide load data and load index and pesticides are assessed on three different levels:
- Health (Calculation of the effect of pesticide load on human health)
- Environmental fate (Degradation in soil, bioaccumulation, mobility in soil)
- Environmental toxicity (Determined by using several sub indicators in nature)
’Environmental fate’ is the assessment most comparable to SIRIS and the Environmental Yardstick for Pesticides. However, note that it is difficult to compare assessments from the individual countries as they use very different methods and assessments.
In the Danish assessments, Boxer (prosulfocarb) and Stomp (pendimethalin) have high leaching risks. The rest of the examined pesticides had medium-low leaching risk Table 10.
The Danish legislation uses health, environmental behaviour and environmental impact as parameters and based on this, a pesticide tax is calculated in relation to normal dosage in the treatment index (TI). “The calculation of the Treatment Frequency Index (TFI), which reflects pesticide use nationally, is based on the standard dose of each product for each crop and the annual sales of pesticides. At farm level, on the other hand, the Treatment Index (TI) reflects the number of times the farmer has treated his land with pesticides in a growing season if standard doses were used. TI and TFI are in many ways one and the same term; application and substitution are done by the farmer whilst the TFI is a statistical average calculation at national level. The calculation of TI is used for individual farms for advisory purposes and to decide on the use of pesticides in a given crop.” From The Agricultural Pesticide Load in Denmark 2007-2010
Each crop has a dosage corresponding to 1 TI, e.g. use of Boxer in winter crops have a dosage of 3.5 litres per hectare and a pesticide tax of 26 DKK/litre or approximately 3.5 Euro/litre. This means that if the farmer applies 3.5 litres in the field, there is a tax of 12.2 Euro. This encourages Danish farmers to use low doses of pesticides. There are several levels to test and it is complicated if the farmer uses a mixture of 2-4 different agents, which is very common in Denmark. For this reason, the dosages can be considered on 4 levels, which also increases complexity when making comparisons:
- Maximum dosage in the treatment index (TI).
- Maximum dosage allowed to protect the crop.
- Dosage used as a single product by the farmer in the field
- Dosage used in mixtures by the farmer in the field
In this test the maximum dosage in the treatment index (TI) was used.
In the test, the SIRIS ”Le-rang” is compared to Environmental Yardstick for Pesticides (assuming a soil organic matter content of 1,5 - 3% and autumn application), Danish pesticide taxes are based on normal dosage in the treatment index (TI) in the Danish Plant Protection Product Database and the Danish risk profile ’Environmental fate’.
Figure 5 shows a section of the Danish Plant Protection Product Database with approved agents and their dosage for treatment index (in Danish: Behandlingsindeks (BI)) and pesticide taxes. The results of the comparison of Environmental Yardstick for Pesticides and the Danish pesticide taxes are presented in Figure 6. The results of the comparison of the Danish pesticide taxes, Environmental Yardstick for Pesticides and SIRIS are presented in Figure 7. The results in Figure 6 and Figure 7 indicate that there is not much similarity between the 3 different leaching risk assessments.
An agent used by all the countries is glyphosate. In this test Roundup Bio (glyphosate 360 g/litre) was assessed to be 82 percent in SIRIS - that is a high leaching risk, while the Environmental Yardstick for Pesticides in the Netherlands indicate low leaching risk on soils with a content of 1 - 3% organic matter. The Danish assessment is low-medium based on the size of the taxes and the level of Environmental fate. The herbicide Boxer (prosulfocarb) was assessed to have a high risk in Denmark, medium risk in France and low-medium risk in the Netherlands. The desiccant herbicide Reglone (374 g/l diquat) had a very high risk profile in Denmark and France, but not in the Netherlands. The agent will be banned in the EU from 2020. The advantages and disadvantages of the Environmental Yardstick for Pesticides and SIRIS are summarized in Table 11.
Table 11. Advantages and disadvantages of the Environmental Yardstick for Pesticides and SIRIS applied in a Danish context.
|Environmental Yardstick for Pesticides||SIRIS||Environmental Yardstick for Pesticides||SIRIS|
|Suitable as an advisory tool for advisors and farmers at farm level.||A surveillance program that can handle leaching of pesticides at catchment level.||Designed mostly for single products and not so much for mixtures.||Expert program. Unsuitable as an advisory tool for advisors and farmers.|
|Very visual tool that is easy to understand and use for advisors and farmers.||Missing the connection/link to the weeds to be controlled at farm level.||The program try to show the connections between the findings in groundwater and the use of pesticides in a specific area.|
Lack of calculations in relation to the resistance challenge in weed control, pests and fungal diseases.
The conclusion of this test is that it will be difficult to implement SIRIS and Environmental Yardstick for Pesticides in Denmark, since the assessments are very different from the assessments behind the Danish legislation concerning pesticide taxes, which are taxes that reflect the risk of the pesticide in several areas.
As the Danish assessments are based on health, environmental behaviour and environmental impact parameters and not just leaching risk, the comparison is not entirely fair. It would be fairer to compare only the leaching risk as this is the only risk assessed in SIRIS and the Environmental Yardstick for Pesticides. In general, the Danish government bans all pesticides with high leaching risk to ensure the quality of Danish groundwater. This is an ongoing process as knowledge increases. The table from The Agricultural Pesticide Load in Denmark 2007-2010 also reflects that most of the pesticides has a medium-low leaching risk.
SIRIS and the Environmental Yardstick for pesticides can be used as inspiration to further develop the Danish Plant Protection Product Database where currently environmental assessments are not transparent. The Environmental Yardstick fro Pesticides is good for visually showing the environmental impact of pesticides while this is hidden in Plant Protection Online for the users. In Denmark, it is assumed that the government removes pesticides with high leaching risks and for this reason the Danish Plant Protection Product Database has focused mainly on helping users to choose the right pesticides for the specific problem in the individual field – i.e. the program is specialised in handling very different weed community compositions and single species with the right dosages in order to lower consumption compared to the recommended dosage on the label.
TargetEconN is a Danish model, developed for the Limfjord catchment, where Aalborg is situated. The model is currently set up for all other Danish catchments as well. The model is developed as part of research projects, and is now being used to advise the Danish Ministry of Environment and Food with regard to the implementation of the Water Framework Directive (WFD) with respect to cost-effective choice of mitigation measures, abatement levels and spatial allocation of measures. The model is currently set up for abatement of nitrogen (N) loads to surface water, but will be set up also to include groundwater. The model is furthermore set up for modelling pesticide effect of some of the N mitigation measures in the model, but a full modelling of pesticide reductions have not been implemented in the model.
TargetEconN include field parcel level input for 12 different mitigation measures, for clay and sandy soils, effect of nitrogen abatement in kg N/ha and costs in DKK/ha. The N load reduction targets are set for catchments draining to Limfjorden, and the model is flexible to include smaller (ID15 i.e. catchments of approximate 15 km2) or larger catchments.
Figure 8 shows the cost-effective distribution of N mitigation measures for fulfilling WFD, and also the distribution of costs, at field parcel level. The model has been used to test how model results are affected by uncertainty on the data and assumptions on the retention of N in the catchment.
The model has been tested in the Limfjord catchment where Aalborg is situated, and this is the catchment where the model has been developed. The model is set up for Denmark as a whole, as well, divided into 23 catchments and with the ability to subdivide into smaller catchments. The model has not been tested in catchments in other countries. The model will be compared with other Danish cost-effectiveness models (SMART and Norsminde) but the results of these model simulations and tests for the other models are not yet finished. This test is documented in in »Assessments of costs and benefits using decision support tools and differences and deviations in cost-effective solutions between these models are analysed.
TargetEconN solutions have been discussed with the Water Utility Company in Denmark in an interview, and the conclusions from this test is that
- the distribution of mitigation measures on field level is attractive as information for the utility, but
- the cost-effective solution might be difficult to use in negotiations with farmers about where and how much to implement in terms of groundwater protection.
The maps have not been tested on farmers, however. TargetEconN and the resulting maps and solutions have also been discussed with the Ministry of Environment and Food, and opposite to the Water Utility company the Ministry is not in favour of too spatially detailed information at field level. The Ministry indicates that information on cost-effective solutions is of interest as advise, but also that having information from several sources and models provides results as a range, and that this range is important for trust building in the results.
For full references to papers quoted in this article see » References