Urban and peri-urban lands can be an important source of food production for localised and sustainable food systems, however, their soils can be of poor quality, degraded or damaged by anthropic activities, and little is known about their suitability or safety. This paper aims to contribute to this knowledge gap by assessing the soil remediation capacity and qualities of different types of compost made from urban and peri-urban organic wastes for agroecological food production. Prepared over the course of 2021, and used in 2022 for food growing, five different composts were observed and analysed, in two different farms in the city of Rosario, Argentina. Four raw materials generated largely by local industries were used to make the composts: chicken manure, rumen (cow's stomachs), brewer's bagasse (byproducts of the beer industry) and urban leaves collected from the municipality waste collection. These were mixed in different proportions (all reaching the 20-30 C/N ratio, typical of quality compost) to produce viable growing substrates where radishes and lettuces were grown. The aim of the study was to assess the possibility, quality and limitations to use locally available organic inputs for soil fertility management in agroecological farming, in the context of urbanisation and to assess pathways to develop closed-cycle agroecological agriculture at metropolitan level. Natural manure substrates (raw and composted) were analysed, as well as crops grown and fertilised with each of the substrates. The attributes and limiting factors of each substrate and their response to local soil conditions were compared and physicochemical, biochemical, and microbiological analyses were performed, including among others, the study of microbial biomass, biological activity, biophytotoxicity, pH, aerobic heterotrophs, nitrogen fixation, and the presence of antibiotics, agrochemicals and heavy metals. The results of the analyses show that all the composted materials improved the physical, chemical and biological properties. However, in some cases, pollutants were present even after composting. Analysis carried out on the vegetables generally indicate undetectable levels or levels below the admissible limits, demonstrating the filtering capacity of the different composts and the soil.

The aim of this research was to determine the impact of hydrogen peroxide spraying and ozone gas fumigation during the growing season of tomato plants grown under cover on the mechanical and chemical parameters of fruit harvested from these plants. Tomato plants were grown under cover in accordance with the principles of good agricultural practice in the soil and climatic conditions of southeastern Poland. During the growing season, tomato fruits were collected for testing in order to determine the impact of the applied variable factors on the modification of selected metabolic pathways of bioactive compounds. As part of the tests on the chemical properties of the fruits, the content of ascorbic acid, the total content of polyphenols, and the antioxidant potential were determined. Additionally, the influence of the tested variable factors on the mechanical properties of tomato fruits was determined. In the case of the total polyphenol content, the most beneficial effects were observed for fruits collected from plants treated with ozonation at a dose of 2 ppm for 3 min and spraying the plants with 1% hydrogen peroxide. The highest antioxidant potential was recorded for fruits of the variants ozonated with doses of 2 ppm for 1 min, 2 ppm for 1.5 min, and 2 ppm for 3 min compared to the remaining variants and controls. In turn, the vitamin C content increased significantly in the tested fruits after the ozonation of plants with a dose of 2 ppm for 1 min and ozonation with a dose of 2 ppm for 3 min combined with spraying plants with 3% hydrogen peroxide. In the case of the mechanical properties of tomato fruits, only the ozonation dose of 2 ppm for 3 min significantly improved them.

Biomass burning contributes considerably to black carbon (BC) emissions in South Asia, but such emissions have not been linked with the Green Revolution (GR) which has enabled substantial crop production growth in South Asian countries, India in particular. Here, we use an Earth system model to quantify climate change through the direct radiative forcing (DRF) by agriculture-emitted BC associated with the GR in India. We show that the BC DRF in India has increased significantly since the GR, especially during the post-GR period. The estimated BC DRF in India rose from +0.197 W/m(2) in 1961 to +0.805 W/m(2) in 2011; this represents a fourfold increase in DRF since the onset of the GR. The contribution of BC DRF by India's intensive agriculture to the global BC forcing also increased from 2.6% to 4.4% during the GR. Our results reveal that increasing BC emissions associated with the GR raises the importance of emission mitigation from agriculture source.