Bekæmpelsesmiddelforskning fra Miljøstyrelsen Nr. 115 2007 – Vurdering af Planteværn Onlines økonomiske og miljømæssige effekt

Vurdering af Planteværn Onlines økonomiske og miljømæssige effekt

Summary

The Pesticide Plan 2004-2009 states that the objective of a treatment frequency of 1.7 should be achieved through focused guidance at farm level. The intentions are that existing knowledge of needs-based pesticide applications should be disseminated to farmers. One of the means for assessing the needs-based pesticide allocation in the action plan is Crop Protection Online, a decision support system that is being developed in collaboration between the Faculty of Agricultural Sciences (DJF) at the University of Aarhus (formerly the Danish Institute of Agricultural Sciences (DIAS)) and the Danish Agricultural Advisory Service (DAAS). On the basis of field scouting, the system can suggest treatments for weed control in most major crops whereas the disease and pest modules are as yet only developed for cereal crops. Originally, the system was targeted at the individual farmer’s decisions during the growing season, but it has gained most ground as a decision support system for advisers and consultants. At agricultural colleges the system serves as a learning tool for building knowledge on crop protection. The number of farmers who actually use the system is relatively limited, approx 800, which corresponds to about 3% of the farms with more than 20 ha acreage.

The purpose of the project is to obtain better knowledge of how the decision support system Crop Protection Online can be integrated into the decision-making process and to quantify the economic and environmental effectiveness of decision support systems in Danish crop protection and to develop sensitivity analyses relating to the use of Crop Protection Online.

The project is based on the answers of the following questions:

To what extent is the decision support system used and what do the farmers expect from decision support systems in relation to crop protection?
What are the economic and environmental advantages of using Crop Protection Online compared to other crop protection strategies?
What are the possibilities of improving the agronomical/economic basis for decisions in Crop Protection Online?
What is the possible distribution potential of Crop Protection Online in practice and which barriers exist as regards its use?
What are the possibilities of developing new approaches to the use of the Crop Protection Online system?

In this project Crop Protection Online was analysed based on a biological, an economic and a sociological approach to provide – as broadly as possible – the necessary basis for assessing the potential of the present system. The project has limited its activities to cereal crops only, which cover approx 60% of the total agricultural area and also fully 60% of the total pesticide consumption.

Biological and technical basis

Crop Protection Online was developed on the basis of an agronomical-technical idea that the total consumption of pesticides can be reduced considerably if the pesticides are used according to a needs build on field assessments and the inclusion of agricultural conditions in the specific field. A large number of validation trials with Crop Protection Online have been conducted over the years. Trials with both herbicides and fungicides have generally shown satisfactory recommendations with regard to the achieved control and net yield gain, just as the system has recommended a low pesticide input. Validation trials with fungicides in cereals have indicated only a very limited and uncertain reduction potential compared to the present fungicide consumption. The fungicide input in the trials is thus in agreement with the input calculated from the official pesticide statistics (2003-2005), which also is in agreement with the target figures envisaged by the 2004-2009 action plan.

The weed model in Crop Protection Online has been tested in various trial series and has shown a satisfactory weed control and a theoretical reduction potential of at least 40% measured in comparison with the consumption calculated as an average of the pesticide statistics 2003-2005. The reduction potential is slightly bigger in spring cereals compared to winter cereal. The difference between the amounts of herbicides used in the Crop Protection Online trials and the amounts used in practice has decreased in recent years. This probably reflects a larger need for herbicides compared with previous years. The trials from the most recent years especially reflect a larger need for spring treatments, which have contributed to a higher treatment frequency index. The changes in the need for control in recent years are – among other things – due to more winter cereals in the crop rotation and earlier sowing in the autumn. In practice, the increasing use of reduced tillage has also contributed to increasing problems, especially with grass weeds.

There are considerable knowledge gaps and problems with upgrading from field trials to proper field conditions. The weed flora in the performed trials is, however, generally assessed as being large to very large and definitely representative of the present weed situations in cereals. However, we must assume that the number of weed species will increase when we go from trial level to field level, and with that the necessary input will probably need to be increased as well.

As a whole, Crop Protection Online has the potential to contribute considerably to achieving the target figures set for 2009. There is a considerable pesticide reduction potential (based on the 1996-2006 trials) if the recommendations of the system are followed and a field-specific treatment of the dominant weed species is carried out. Calculated only on the basis of the reduction potential for herbicides in winter cereals and spring barley, the Crop Protection Online system can contribute a reduction from the present 2.32 in 2005 to 1.91. This is a considerable contribution to the desired reduction target of 1.7 for 2009. If the reduction potential of Crop Protection Online in other crops is included as well, the potential will increase.

Economic basis

The Pesticide Action Plan 2004-2009 is based on analyses showing that viewed separately an input that corresponds to a treatment frequency index of 1.7 is the economically optimum level for pesticide consumption in Denmark. Assessed on the assumption that farmers act in an economically rational manner, this target should therefore be realistic. However, the analyses do not include conditions relating to decision behaviour, and because the difference between an economically optimal input and a standard solution often is less than 100 DKK/ha, there is no motivation to act in an economically optimum way.

Based on the documented reduction potential of Crop Protection Online with respect to herbicide input, it is estimated that 137 and 54 DKK/ha can be saved in winter cereals and spring barley respectively after deducting expenses for field scouting. This is a relatively large saving, but if the saving is related to the fact that the demands on manpower, time, planning and farm management at a superior level are increased, this may overshadow and undermine the potential for making savings.

Analyses of historical data for both fungicides and herbicide trials have clearly shown that the recommendations in Crop Protection Online are robust and near the economic optimum. However, in some situations the system may recommend too high a pesticide input. Many farmers typically wish to use a slightly higher dosage in order to – among other things – counter the risk of a poorer effect, for instance as a result of climatic variations. However, the analysis of the historical data has shown that economic certainty does not increase with dosage. Quite the contrary!

Sociological basis

During the project a study was carried out in the form of a questionnaire with 746 returns (61%) and 4 focus group interviews to explain how farmers make their decisions on the use of pesticides and to identify the barriers to a more extensive use of the present Crop Protection Online. The analyses indicated 3 different decision rationales in connection with spraying: 1) system-oriented decision-makers, 2) experience-based decision-makers, 3) contracting decision-makers. None of the 3 groups could match the value rationales on which Crop Protection Online is based and the acts required in connection with the use of Crop Protection Online. A pronounced barrier in the study is the requirements of field scouting, which is necessary in relation to the optimal use of Crop Protection Online. More than 75% of the farmers who knew Crop Protection Online indicated that they do not have the time necessary to carry out specific field scouting and that Crop Protection Online does not fit the way decisions are made at the farms. Among farmers, who are not familiar with Crop Protection Online 86% stated that they preferred a dialog with their local consultants rather than using a system like Crop Protection Online.

The results of the sociological study left no doubt that it is important that the development of decision support systems should take place in a close dialogue with the relevant user groups. Different groups of farmers have different needs of knowledge and information, and it cannot be expected that one system will appeal to all user groups at the same time. The farmer study also provided specific wishes and suggestions for improving the system, for example that it should be possible to connect Crop Protection Online to other computer systems used by the farmers; that it should be possible to use Crop Protection Online to a larger extent in the planning phase and independently of the time of season and that the system should give a larger degree of varied answers that among other things include varying requirements concerning acceptable weed levels in different crop rotations.

Alternative approaches to Crop Protection Online

To reduce the barrier attached to field registration work was carried out on developing alternative approaches to Crop Protection Online. These alternative approaches do not require detailed field scouting. Results from two years of national field trials with tests of alternative approaches to Crop Protection Online have indicated that this potential exists and that there is a basis for continuing the work with this concept. Instead of specific disease data from the field we have used regional disease data and climatic information, whereas for weeds an incomplete recording of weeds was used, which is based on the recollection and experience of the farmer from previous years. For both disease and weed control there are indications that the consumption of pesticides will increase a little compared with the use of field specific data, but this increase has overall been rather limited.

Further development of the prototypes with alternative approaches will require a close dialogue with identified user groups to ensure that those needs and methods are targeted that are compatible with the farmers’ ways of handling crop protection and which – among other things – are identified in the sociological study.

Conclusions and recommendations

Theoretically, the objectives of the Pesticide Plan can be achieved in cereal crops via the knowledge basis accumulated in Crop Protection Online, which is also confirmed by practical field tests. However, the need for performing actual field scouting before using the system has in practice proved to be an important barrier to fulfilling the potential of the system.

Economic analyses show that Crop Protection Online recommendations are economically reasonable in view of the given demand for control levels. However, analyses of historical data indicate that – based on a long-term view in a limited economic sense – there is scope to come closer to the economic optimum in some areas by using lower dosages. The results of these analyses are, however, inconsistent with the way most farmers view the risks, which in practice focus more on avoiding unintentional disruptions of their management system, whether in the form of extra work, incidents of unacceptably low yields and/or negative aesthetic experiences in relation to their occupational pride.

The greatest barrier to making Crop Protection Online work as an instrument is thus its poor distribution and use in practice. The 3% practical farmers who use the system are far below its theoretical potential of between 30 and 50% users for this kind of tool. The indirect use of Crop Protection Online via the advisory system is generally thought to be considerable but has never been specifically quantified. Recommendations given by the advisory system are often based on output from Crop Protection Online but are of a more general nature and not field-specific.

Although there generally is much confidence in the technical contents of Crop Protection Online, the sociological study shows that Crop Protection Online does not address some of the identified decision strategies in a sufficiently unambiguous manner. For most farmers, crop protection is only a small part of the continuous flow of operations and decision-making processes that are made at farms. Decisions on crop protection are not based on an isolated economic consideration, but are coupled with a number of other considerations and factors at the farm: machinery, manpower, task planning, etc.

Increased distribution of Crop Protection Online depends on the user interface and the functionality of Crop Protection Online being targeted to a larger extent at the individual decision strategies, and we recommend that representatives of these decision strategies should be very actively involved in ongoing development processes.

Crop Protection Online requires very specific input and field observations. In the project we have therefore tested Crop Protection Online prototypes with simplified input. The test showed that it is possible to simplify the input requirements without affecting consumption and yield significantly. The prototypes are not fully developed yet, and it is not clear to what extent the alternative approaches may increase the number of active users of Crop Protection Online. Therefore, we do not expect that the new prototypes will be widely distributed and have much effect on the treatment frequency index within the present Pesticide Action Plan 2004-2009.

Crop Protection Online is altogether assessed as being an important tool in the efforts to achieve a needs-based use of pesticides. In its present form, however, the system will only to a limited extent be able to contribute to achieving the reduction targets in the Pesticide Action Plan 2004-2009. However, Crop Protection Online cannot stand alone but should be seen as one of a wide range of tools for achieving the targets. Our recommendations for the future development of the system are:

that new user interfaces and their functionality should be developed and that this development should take place in a close collaboration with the farmer target groups.
that Crop Protection Online for some areas specifically should be developed as a tool handling the interactions between consultant-farmer, possibly scout-farmer or finally all three parties.
that new technologies can revitalise applications of Crop Protection Online, in particular by succeeding in combining new sensor techniques, GIS, the use of injection sprayers with the knowledge base of Crop Protection Online. However, this development requires a major and targeted research effort before being implemented.
a large part of the arable farmers cannot be reached via Crop Protection Online, directly or indirectly. It is therefore important to look at alternative solutions such as qualified standard solutions, etc., which viewed broadly can compete with Crop Protection Online.
that Crop Protection Online will be kept up to date also in the future, as it is an important tool, especially because it is a generally recognised knowledge database that already indirectly plays a major role in the recommendations passed on to farmers.

Finally, the project group considers it important that ways are found of getting into a dialogue with those arable farmers that are not immediately accessible via the advisory system or Crop Protection Online so as to not only spending energy on the people with whom you are already in contact and for whom the real reduction potential is limited.