Exploring Secondary Metabolites in Coffee and Tea Food Wastes

Coffee and tea are popular beverages worldwide, and therefore generate large amounts of waste. Here we describe the caffeine content and phenolic profile in three types of teas and coffees, and how they vary with two successive extractions. Although the first extraction was far more efficient than the second, green tea also showed a high content of flavanols in the second extraction, as did mate tea for phenolic acids. Black tea could also be a good option since caffeine content was highest in both extractions. Water also proved to be the most effective solvent in almost all cases, which represent a major benefit for urban horticulture, as it is a simple extraction method from an easily accessible source. Coffee and tea residues are a rich source of caffeine and phenolic compounds that could potentially be used as alternatives to conventional pesticides.

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

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.

Urban horticulture.

At the beginning of the 19th century Heinrich von Thunen developed a model on agricultural land usage. The model generated four concentric rings of agricultural activity with dairy and intensive farming being closest to the city centre. The use of a piece of land is affected by the physical potentialities of the soil, but mainly depends on the cost of transport to market. Dairy and intensive farming are closest to the city centre since vegetables, fruit, milk and other dairy products must get to the market quickly. This is one reason for the development of peri-urban vegetable farms in the 19th century that produced high value products with high perishability. Due to its intensive character and important role for feeding people, horticulture in and around the city is widespread and its development is growing in relation to increasing city sizes. Cities of the developing world are somewhat more advanced in the development of multifunctional urban horticulture, as described by de Bon et al. (2015), but very diverse new forms are emerging in Northern hemisphere countries. One challenge of urban production is to produce safe food in an urban, often-polluted environment. In this article, following a description of urban horticulture, some main components are discussed in relation to current concerns and evolutions: the diverse cropping systems and the business models associated with that form of horticulture; the provided ecosystem services; the evolution of technologies in relation with soil and product quality; the diversity of crops; economic values and organizational forms.

Urban Horticulture for Food Secure Cities through and beyond COVID-19

Sufficient production, consistent food supply, and environmental protection in urban +settings are major global concerns for future sustainable cities. Currently, sustainable food supply is under intense pressure due to exponential population growth, expanding urban dwellings, climate change, and limited natural resources. The recent novel coronavirus 2019 (COVID-19) pandemic crisis has impacted sustainable fresh food supply, and has disrupted the food supply chain and prices significantly. Under these circumstances, urban horticulture and crop cultivation have emerged as potential ways to expand to new locations through urban green infrastructure. Therefore, the objective of this study is to review the salient features of contemporary urban horticulture, in addition to illustrating traditional and innovative developments occurring in urban environments. Current urban cropping systems, such as home gardening, community gardens, edible landscape, and indoor planting systems, can be enhanced with new techniques, such as vertical gardening, hydroponics, aeroponics, aquaponics, and rooftop gardening. These modern techniques are ecofriendly, energy- saving, and promise food security through steady supplies of fresh fruits and vegetables to urban neighborhoods. There is a need, in this modern era, to integrate information technology tools in urban horticulture, which could help in maintaining consistent food supply during (and after) a pandemic, as well as make agriculture more sustainable.

Impetus of urban horticulture on open spaces: case of Mutare City

Purpose: To understand the impetus of urban horticulture in the Mutare city with explicit motivation on low density areas. Research methodology: The investigation was quantitative in nature, and used a random sample of urban farmers in Mutare city low density areas. The Statistical Package for Social Scientist (SPSS Version 23) was used to analyse data from the questionnaires. Results: The results reveal that Mutare urban agricultural activities are driven by the need for food self-sufficient, income generation and utilisation of urban open spaces. Limitations: The research had limitations on the sample size and also needed to factor in other multiple response questions. Contributions: The findings are useful to urbanites, urban planners, developmental agents and authorities in the development of urban agriculture. Keywords: Urban horticulture, Urban agriculture, Mutare, Impetus, Food security

Towards sustainable performance of urban horticulture: ten challenging fields of action for modern integrated pest management in cities

We identified ten current key challenges for plant protection in cities each of them belonging to a specific field of action of IPM in urban horticulture according to Directive 2009/128/EC. The challenges are: appropriate plant selection, microbiome engineering, nutrient recycling, smart, digital solutions, diversification of vegetation, avoidance of pesticide side effects on beneficials, biorational efficacy assessment, effective pest diagnosis, efficient outbreak control and holistic approaches. They are discussed on the background of the defined urban horticultural core sectors (a) public green infrastructure, including professional plant care, (b) professional field and greenhouse production systems and (c) non-professional private homegardens and allotments.

The Possibility of Sustainable Urban Horticulture Based on Nature Therapy

Population growth and increased stress caused by urbanization have led to social problems that are predicted to intensify in the future. In these conditions, the recently established ”nature therapy” has revealed that an environment rich in various plant life significantly contributes to the relief of physical and mental stress. Meanwhile, from the perspective of reduction in the energy required for transportation and the retention of plant freshness, urban horticulture, in which plant life exists harmoniously with the city, has attracted considerable attention. Interactions between humans and plants in urban horticulture are considered to contribute to the good health and wellbeing of people. Therefore, we incorporate human-centered thinking based on nature therapy into horticultural produce-centered thinking based on conventional urban horticulture. By introducing a pioneering urban horticulture plant factory as an example, we propose the possibility of sustainable urban horticulture based on nature therapy.