Assessing the Direct Resource Requirements of Urban Horticulture in the United Kingdom: A Citizen Science Approach

Abstract

Interest in urban food production is growing; recent research has highlighted its potential to increase food security and reduce the environmental impact of food production. However, resource demands of urban horticulture are poorly understood. Here, we use allotment gardens in the United Kingdom to investigate resource demands of urban horticultural production across the country. We conducted a nationwide citizen science project using year-long allotment ‘diaries’ with allotment gardeners (n = 163). We analysed a variety of resources: transportation; time; water use; inputs of compost, manure and topsoil; and inputs of fertilisers, pest control and weed control. We found that, overall, an allotment demands 87 annual visits, travelling 139 km to and from the plot; 7 fertiliser additions; 4 pest control additions; and 2 weed control additions. On average, each kilogram of food produced used 0.4 hours’ labour, 16.9 L of water, 0.2 L of topsoil, 2.2 L of manure, and 1.9 L of compost. As interest in urban horticultural production grows, and policy makers build urban horticultural spaces into future sustainable cities, it is of key importance that this is carried out in a way that minimises resource requirements, and we demonstrate here that avenues exist for the diversion of municipal compostable waste and household-level city food waste for this purpose.

Food production and resource use of urban farms and gardens: a five-country study

“…Pollard et al ( 2018a ) pointed out that there are not many articles focusing on the measurement of irrigation water consumption in UA, and Whittinghill and Sarr ( 2021 ) found that irrigation was the least-recorded practice among urban farmers and gardeners surveyed. Our results are largely consistent with the largest known survey to-date, a study of 163 allotment plots in the UK (Dobson et al 2021 ). While they found a much smaller average than ours overall (16 L/kg vs 71.6 L/kg), their findings were much closer to our average for individual gardens (16 L/kg vs 40 L/kg), which reflects our findings that individual gardens may use water more efficiently than collective gardens or urban farms, or they may simply under irrigate.…”

“…It is perhaps not surprising, then, that our results are inconsistent with this limited literature. For example, Dosbon et al ( 2021 ) found an average of 1.9 L compost used/kg food in allotment plots, compared to a mean and standard deviation of 5.5±6.3 L/kg and median of 3.0 L/kg here for the 38 sites that used compost. On an area basis, these sites used an average of 9.7±11.5 L of compost/m 2 , with a median of 4.9 L/m 2 .…”

“…Our results are largely consistent with the existing literature on inputs in UA. Numerous surveys of UA have found that compost is the main input and compost production is the main practice, often followed by the use of manure or other organic amendments, with synthetic fertilizers and pesticides used less frequently (Guitart et al 2012 ; Dewaelheyns et al 2013 ; Gregory et al 2016 ; Kirkpatrick and Davison 2018 ; Pollard et al 2018b ; Wielemaker et al 2019 ; Edmondson et al 2020 ; Nicholls et al 2020 ; Dobson et al 2021 ; Whittinghill and Sarr 2021 ). While it is helpful to understand the types of inputs used by UA, there is a clear gap in the literature when it comes to quantifying the amount of input used on urban farms and gardens.…”

“…There are studies that have evaluated more than 50 cases, but these usually have a rather narrow focus on food production and do not assess resource consumption (CoDyre et al 2015 ; Nicholls et al 2020 ; Edmondson et al 2020 ). Dobson et al ( 2021 ) had a large sample size (163 participants) and measured a suite of indicators covering food production and resource use, but only studied one type of UA, allotment gardens.…”

The Importance of Citizen Scientists in the Move Towards Sustainable Diets and a Sustainable Food System

“…We highlight that our examples are focused on citizen science at the production, processing and consumption stages of the food system, with food system inputs (natural resources, manufactured inputs or human resources) all offering their own potential citizen science engagement opportunities. Indeed, examples of irrigation (Buytaert et al, 2014;Ramirez-Andreotta et al, 2015;Pérez-Belmont et al, 2019), fossil fuel (Zilliox and Smith, 2018) or other input-based citizen science are currently present in the literature (Dobson et al, 2021).…”