Pesticide usage - rodenticides on arable farms 2018: survey results

Supplementary data

In addition to the collection of rodenticide usage data, farmers were also asked a series of supplementary questions relating to aspects of their farm operation, their use of non-chemical rodent control, rodenticide stewardship and their compliance with best practice in rodenticide use.

In contrast to the rodenticide usage data presented in the previous sections of this report, this information is not raised to provide national estimates of use, but is presented as responses from the sample surveyed.

Non-chemical rodent control

Farmers were asked about non-chemical methods employed for rodent control. A range of measures were conducted, with some farmers employing more than one method (Figure 10).

Figure 10 Non-chemical control on arable farms (percentage of total methods used) 2018

On holdings on which rodenticides were not used (n=60), 60 per cent of the farmers reported using one or more non-chemical controls. The most commonly encountered methods were use of cats and traps (68 and 22 per cent of all methods reported respectively). Shooting, dogs and use of an electronic scarer were also used to control rodents.

On holdings using rodenticides (n=211), 46 per cent reported that they used additional non-chemical methods of rodent control. Again, the most common methods used were cats and traps (45 and 25 per cent of all methods reported respectively) with lower use of dogs and shooting.

The number of farmers reporting that they employed non-chemical rodent control was greater in 2018 than in 2016 and 2014 on holdings where rodenticides were used (46, 26 and 10 per cent respectively). For holdings where no rodenticides were used the numbers reporting the use of non-chemical rodent control was similar in 2018 and 2016 (60 and 61 per cent respectively) but higher than that reported in 2014 (44 per cent).

Compliance with rodenticide best practice

All farmers and PCPs who were responsible for rodenticide baiting on the surveyed farms were asked about their training history and their compliance with the principles of best practice of rodenticide use⁽⁷⁾ (Table 3).

These data are expressed as percentage of respondents giving a positive answer to each question. Not all of those surveyed provided this data, responses were provided by 72 farmers, representing 99 per cent of those farmers who conducted their own rodenticide baiting and 20 PCPs, representing 65 per cent of the contractors encountered during the survey. Where statistically significant differences in the response between farmers and PCPs were found these are noted.

Ninety-five per cent of PCPs and 36 per cent of farmers had attended a training course on rodenticide use. The uptake of training was significantly different between farmers and PCPs (P<0.001).

All PCPs and 94 per cent of farmers stated that they recorded the quantity and location of baits. All PCPs and 99 per cent of farmers stated that these baits were protected from non-target animals. Bait was reported to be regularly inspected by all PCPs and farmers.

Sixty-five per cent of PCPs and 75 per cent of farmers removed bait after targeted baiting periods.

All PCPs and 90 per cent of farmers stated that they searched for and removed rodent carcasses. Many respondents stated they rarely saw carcasses. However, those farmers who did encounter carcasses employed a range of disposal methods; primarily burying, but also landfill, incineration and disposal in dung heaps (refer to table 3 for details).

The pattern of responses to these questions, both by farmers and PCPs, are very similar to those provided in the 2016 arable crop survey. In 2016, there was a significant difference in farmer and PCP response in relation to searching for rodent carcasses. However, in 2018 many more farmers reported searching and removing carcasses (90 per cent) which meant there was no significant difference between farmer and PCP response.

Farm operation data

Farmers were asked a series of questions relating to aspects of farm operation which might affect rodenticide use pattern (Table 4). Not all of those surveyed provided this data, responses were provided by 267 farmers, representing 98 per cent of the farms sampled overall.

The majority of respondents (94 per cent) were a member of a quality assurance scheme, similar to the 92 per cent recorded in 2016. A range of assurance schemes were encountered; the most common were Quality Meat Scotland (QMS) and Scottish Quality Crops (SQC). Both of these schemes specify that effective rodent control measures must be in place, although the use of anticoagulant rodenticides is not mandatory. Membership of both QMS and SQC also permits purchase and use of rodenticide products authorised under stewardship conditions. More farms that practised rodenticide baiting were members of a quality assurance scheme (96 per cent) than farms that did not use rodenticides (85 per cent) and this difference was significant (p-value 0.002).

Although all the farms surveyed grew arable crops, some were also mixed farms and 59 per cent of those surveyed kept livestock on their holding, compared to 53 per cent in 2016. Only two per cent of farms had a pig unit and one per cent had a poultry unit. These intensive livestock production sectors tend to be greater users of rodenticides due to storage of large volumes of feed and concern about feed spoilage and rodent related disease.

Lastly, 66 per cent of holdings surveyed had an on-farm grain store, and a significantly greater number of farms using rodenticides had a grain store (74 per cent) than farms that did not use rodenticides (37 per cent) (p<0.001).

In 2018, as in 2016, statistically significant differences between those farmers using and not using rodenticides were only found in relation to quality assurance membership uptake and presence of a grain store.

Rodenticide approval and stewardship

EU and UK Regulatory risk assessments have concluded that the use of First and Second Generation Anticoagulant Rodenticides outdoors present a higher level of risk to non-target animals (such as predatory birds and mammals) than would normally be considered acceptable. As a result, outdoor use of these rodenticides would not usually be approved. However, the UK Government recognises that, despite these risks, outdoor use of anticoagulant rodenticides is necessary for rodent control.

In order to be able to re-authorise these rodenticides for use outdoors, the Government must be assured that the risks will be properly managed to minimise unacceptable effects to non-target species. This has been addressed by an industry led stewardship scheme, managed by the Campaign for Responsible Rodenticide Use (CRRU)⁽⁷⁾, which was launched in 2015.

With the launch of the stewardship scheme providing environmental risk mitigation measures for rodenticide use, HSE has, during 2016 and 2017, re-approved rodenticide product authorisations. As part of this re-authorisation the approval conditions for some products have been amended, notably in relation to the outdoor use of active substances that were previously restricted to use inside buildings (brodifacoum, flocoumafen and difethialone).

These changes may influence rodenticide usage patterns. It is possible, that decreased rodenticide usage (occurrence and weight applied) and increased adoption of non-chemical control reported in 2018 may have been influenced by the introduction of the stewardship scheme and increased uptake of best practice.

Farmers were asked a series of questions to investigate knowledge and participation in the rodenticide stewardship scheme (Table 5). Not all of those surveyed provided this data, responses were provided by 72 farmers, representing 99 per cent of those farmers who conducted their own rodenticide baiting.

Eighty six per cent of farmers were aware of the rodenticide stewardship scheme’s existence in 2018. Twenty five per cent of the farmers surveyed had attended a stewardship compliant training scheme which provided certification acceptable for point of sale purchase of professional rodenticide products. In addition, 21 per cent of farmers stated they intended to complete this training in future. In 2016, 68 per cent of farmers were aware of the scheme, nine per cent had completed stewardship compliant rodenticide use training and 51 per cent intended to complete training in the future. The difference in intention to complete stewardship training may be due to the fact that more farmers are now trained and that professional rodenticide products can now be purchased by membership of a compliant QA scheme. This arrangement was an interim measure at the time of the 2016 survey, therefore, the motivation to complete training may have decreased over time.

Farmers were also asked if they had purchased rodenticides after April 2016, when the product authorisations under stewardship had been implemented. Ninety per cent of farmers had purchased rodenticides (41 per cent in 2016); the majority (69 per cent of purchases) were made by demonstrating membership of a compliant quality assurance scheme. Followed by production of a stewardship compliant training certificate (17 per cent), purchase of amateur products (4 per cent of purchases) and purchasing non-stewardship products available until September 2016 (3 per cent).