People, pollinators and pesticides in peri-urban farming

We used 'citizen science' to collect data on pollinators, crop yields and pesticide use in Brighton and Kolkata to understand more about urban food production.

Overview

In a world of increasing urbanisation in both the developing and developed worlds, producing food in and around cities has the potential to improve both nutritional and health outcomes (SDG 2 and 3), alleviate poverty (SDG 1) and simultaneously provide habitat for wildlife (SDG 15) and create sustainable cities (SDG 11). Currently few data exist regarding the productivity of urban growing, and their agricultural practices, such as pesticide use – which has potential implications for human and environmental health – are largely unmonitored and unregulated.

Pollinators are vital to crop production for the large majority of crops, including those grown in peri-urban areas. However, since there was no data on pollinator populations in urban settings it was unclear whether current pollinator populations in these areas are sufficient to provide adequate pollination to maximise crop yields, given widespread concerns about insect population declines, nor whether urban pollinators were being adversely affected by pesticide use.

Therefore the overall aim of this project is to work with growers to collect much needed data on pollinators and pesticide use in urban food production. As an inter-disciplinary team of researchers - with expertise in ecology, remote-sensing, science policy and environmental law - we developed a ‘citizen-science’ methodology which could be used to examine the potential for urban growing to contribute to sustainable food production in two geographically distinct areas; allotments and gardens in Brighton & Hove, UK and urban and peri-urban farms in Kolkata, India.

Project description

This project was a comparative study of two contrasting peri-urban systems, Brighton, UK and Calcutta, India. The ultimate aim was to gather and analyse new and important data on pesticide use and pollinator impacts that had not previously been available, to raise awareness among peri-urban farmers, and to develop protocols and policy recommendations to better protect pollinators and ensure the sustainability of peri-urban agriculture.

We are used a ‘citizen science’ approach, whereby growers themselves contributed to data collection by monitoring pollinators and crop yields in their own growing spaces. In Brighton, this work was led by a post-doctoral researcher in Life Sciences, Dr. Beth Nicholls, and in India by Dr. Parthiba Basu, director of of the Centre for Pollination Studies in Calcutta. Data collection in Brighton began in May 2017, with growers submitting data online throughout the year, following an initial training workshop in pollinator identification. We held a follow up event to feedback the preliminary results to volunteers. This work was replicated in both regions in 2018, following a meeting between Dr. Nicholls, Prof. Goulson and Dr. Basu in Calcutta in February 2018 co-ordinating methodologies.

We used qualitative methods, such as surveys and focus groups, to understand more about growers’ attitudes to pesticide use. The first set of focus groups was co-ordinated by Dr. Beth Nicholls, and run by Prof. Dave Goulson, Dr. Helena Howe, and Dr. Pedram Rowhani, with input from Dr. Adrian Ely. The aim of these focus groups were to obtain feedback from growers on their experience of taking part in the project, and some preliminary data on what motivated their use of different pest control methods.

In 2019, a GIS-based analysis led by Dr Pedram Rowhani, using data on housing, population and climate, together with the data collected in this project, identified human and pollinator populations at most risk. Following this, via collaboration with the Pesticide Action Network, in 2019 we produced good practice guidelines for minimising environmental and health risks associated with pesticide use.

Timeline and funding

Timeline

March 2017-June 2019

Funding

£99,970

Methods

Urban farming is typically small-scale and poorly regulated; therefore engaging farmers in data collection was hypothesised to be an effective approach where access to farms and formal records is limited. Methods were first piloted in Brighton & Hove. 185 growers were provided with training to collect the following data from their allotment or garden:

  • Insect visits to flowering crops
  • Weight of produce harvested from insect-pollinated crops
  • Frequency and severity of pests and diseases and control methods used A ‘world café’ and online questionnaire were deployed to learn more about growers’ motivations and attitudes towards the environment.

Findings

On average, growers harvested 70 kg (range 2-259 kg) of fresh produce from their growing space, equating to a yield of 1 kg per m2 (10 tonne/ha), with some growers producing up to 9.7 kg/m2 (97 tonne/ha). This compared favourably with conventional crop yields (Oilseed rape =3.6 tons/ha, Wheat= 9 tons/ha).

Limited pesticides were used (<4% used non-organic insecticide sprays), barring slug pellets which were deployed by 58% of growers. Urban growing in the UK context is therefore likely to be beneficial to life on land (SDG 15) both by providing habitat and reduced environmental damage compared to conventional farming. SDG11 calls for sustainable human settlement planning and management, and there is a substantial role for urban farming to provide this, for example via improved access to green space and flood resilience.

Converting yields into the cost of buying organic produce from a supermarket, the maximum reported value of an annual harvest was £2,300, with urban growers producing, on average, £550 worth of fresh fruit and vegetables per year (note this is likely an under-estimate as it considers insect-pollinated crops only). £380 worth of produce was directly ‘owed’ to insect pollination, per grower, per year, confirming that pollination is as vital to urban agriculture as it is to conventional farming.

The main rationale people gave for urban growing was relaxation and the satisfaction of growing their own food, corroborating previous suggestions of additional health benefits aside from nutrition (SDG3).

Conclusion

We are some of the first to quantify the potential for urban growing spaces to contribute to food security (SDG2, 3), alleviate poverty (SDG1) and provide habitat for wildlife (SDG15). Our methods for involving growers in the collection of data could easily be adapted for other countries, and are currently being implemented in Kolkata. 

Related work

We held two events, the first in May 2017 where we held a training event at the Brighthelm Centre in Brighton to explain the aims of the project in more detail to interested volunteers, and provide training in data collection methods.

The second was in November 2017 where we had a follow up meeting for volunteers in which we presented the results of the study, and held focus groups to get feedback from volunteers on their experience of taking part in the project, so that we can improve the methods for the following year.

Beth also spoke about the project at Nerd Nite in April 2018, and gave a talk to Brighton & Hove Organic Gardening Group at the Phoenix Centre in November 2018.

Useful link

The team

Where we worked

Brighton & Hove, England and Kolkata, India