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Willow coppice in intensive agricultural applications to reduce strain on the food-energy-water nexus Texte intégral
2021
Livingstone, David | Smyth, Beatrice M. | Foley, Aoife M. | Murray, Simon T. | Lyons, Gary | Johnston, Chris
The focus of this study is to show that by understanding the food-energy-water nexus, potential unforeseen negative outcomes can be avoided in the pursuit of sustainable development. To do this, this paper uses a novel approach to compare a combined farm and short rotation coppice willow system, in which the willow was planted as a riparian buffer, with a food-only and an energy only system. The impact of each system was investigated through the lens of the food-energy-water nexus using life cycle assessment techniques. Data from previous research was adapted in order to quantify the impacts for a typical Irish dairy farm, which is indicative of intensive agriculture across Europe. On a typical Irish dairy farm, the implementation of a short rotation coppice willow riparian buffer strip could reduce total nitrogen and phosphorus leachate by 14% and 9% respectively. Total CO₂eq emissions could be reduced by 16.5% if energy from the willow displaces fossil fuels, while the impact on milk production and profit is minimal. Thus, the use of short rotation coppice willow as a riparian buffer strip has the potential to reduce strain on the entire food-energy-water nexus. By considering the food-energy-water nexus, the negative impacts of the food-only and energy-only systems were also highlighted.The paper also shows how a better understanding of the food-energy-water nexus supports the United Nations Sustainable Development Goals and could help ameliorate the impact of climate change on the food-energy-water ecosystem.
Afficher plus [+] Moins [-]Floods, soil and food – Interactions between water management and rice production within An Giang province, Vietnam Texte intégral
2021
Livsey, John | Thi Da, Chau | Scaini, Anna | Lan, Thai Huynh Phuong | Long, Tran Xuan | Berg, Håkan | Manzoni, Stefano
Rapid intensification of Vietnamese rice production has had a positive effect on the nation's food production and economy. However, the sustainability of intensive rice production is increasingly being questioned within Vietnam, particularly in major agricultural provinces such as An Giang. The construction of high dykes within this province, which allow for complete regulation of water onto rice fields, has enabled farmers to grow up to three rice crops per year. However, the profitability of producing three crops is rapidly decreasing as farmers increase their use of chemical fertilizer inputs and pesticides. Increased fertilizer inputs are partly used to replace natural flood-borne, nutrient-rich sediment inputs that have been inhibited by the dykes, but farmers believe that despite this, soil health within the dyke system is degrading. However, the effects of the dykes on soil properties have not been tested. Therefore, a sampling campaign was conducted to assess differences in soil properties caused by the construction of dykes. The results show that, under present fertilization practices, although dykes may inhibit flood-borne sediments, this does not lead to a systematic reduction in nutrients that typically limit rice growth within areas producing three crops per year. Concentrations of total nitrogen, available phosphorous, and both total and available potassium, and pH were higher in the surface layer of soils of three crop areas when compared to two crop areas. This suggests that yield declines may be caused by other factors related to the construction of dykes and the use of chemical inputs, and that care should be taken when attempting to maintain crop yields. Attempting to compensate for yield declines by increasing fertilizer inputs may ultimately have negative effects on yields.
Afficher plus [+] Moins [-]Energy composting allows rapid degradation of food waste using a water bath heated with electricity or solar energy Texte intégral
2021
Food waste is a major issue in the context of pollution, climate change, and the future circular economy. Composting kitchen waste is a promising method to recycle elements, yet the efficiency of composting is limited, calling for new processes that degrade rapidly and thoroughly organic matter. Here, we built a rapid laboratory-scale aerobic composting system, equipped with a water bath fueled with either solar energy, or electricity under low sunlight. We tested compositing with and without energy. Results show that only three days are needed to raise the temperature to over 45 °C by energy composting in winter, leading to notable increases in pH, total nitrogen, and cation exchange capacity after 7 days. Composting materials were thoroughly decomposed and mature in 10 days, displaying pH of 7.5, ratio of total organic carbon to total nitrogen of 9.9, cation exchange capacity of 65.61 cmol kg⁻¹, and germination index of 80.4%. Overall, energy composting starts biodegradation quickly in 2 days, reduces effectively the inhibition from some waste compounds, decomposes organic substances well, and yields mature compost.
Afficher plus [+] Moins [-]Effects of urban demand for food and water on physicochemicals and biotic structure of riverine wetlands in the Pampean plain Texte intégral
2022
Gómez, Nora | Siri, Augusto | Capítulo, Leandro Rodrigues | Colautti, Darío César | Alcalde, Leandro | Rodrigues Capítulo, Alberto | Donato, Mariano | Fernanda Álvarez, María | de Souza, Javier Ricardo García | Jensen, Roberto Francisco | Bauer, Delia Elena | Maroñas, Miriam | Paredes del Puerto, Juan Martín | Altieri, Paula | Armendáriz, Laura Cecilia | Benitez, Hernán Hugo | Cassano, María Julia | Cortese, Bianca | Di Giorgi, Hugo Daniel | Donadelli, Jorge Luis | Gelis, María Mercedes Nicolosi | García, Ignacio Daniel | Maiztegui, Tomás | Paracampo, Ariel Hernán | Sánchez, Rocío María | Sathicq, María Belén | Catanzaro, Ludmila Noelia Soledad Rodríguez
Riparian areas of riverine plains develop extensive floodable areas named riverine wetlands, which are essential to the water cycle balance and ecosystem dynamics. In this study, we contrasted the hydrological and physicochemical variables of riverine wetlands of both peri-urban areas impacted by intensive farming and those of rural areas with the indicators of the biotic structure (taxonomic richness, Shannon diversity and total density) of benthic diatoms, phytoplankton, zooplankton, macroinvertebrates, chironomids, fishes, turtles, and birds. The study was performed on riverine waters of the Pampean plain, Argentina, with four seasonal samplings conducted in 2017–2018. Our results showed that the significant deepening of the groundwater level caused by aquifer overexploitation in peri-urban areas, as well as the declining surface water quality with higher phosphorus and total nitrogen concentrations, affected the taxonomic richness, diversity, and total density of the biotic assemblages of riverine wetlands. The taxonomic richness of birds, turtles, phytoplankton, chironomids, and fishes was the most sensitive to land use. Phytoplankton, chironomid, and fish diversity showed the greatest differences between rural and peri-urban riverine waters, while the total density of chironomids and birds showed the greatest differences according to land use. The results suggest that the socioeconomic development in those riverine wetlands that still maintain conditions close to the natural ones needs to be subject to guidelines derived from integrated basin management and sustainable urban planning.
Afficher plus [+] Moins [-]Effect of Long Term Land Disposal by Spray Irrigation of Food Processing Wastes on Some Chemical Properties of the Soil and Subsurface Water Texte intégral
1975
Adriano, D. C. | Novak, L. T. | Erickson, A. E. | Wolcott, A. R. | Ellis, B. G.
Food processing waste waters at two irrigated land disposal sites and subsurface waters (perched and ground waters) were monitored at daily to monthly intervals over one annual cycle of production. Soil profiles were sampled to depths up to 6.6 m in the early fall. Yearly inputs were calculated at 487 kg/ha total N (Kjeldahl plus NO³-N) and 101 kg/ha soluble PO₄-P (orthophosphate) from cannery wastes at site 1. Estimates for milk wastes at site 2 were 562 kg/ha total N and 522 kg/ha PO₄-P. The range for NO₃-N in subsurface waters was 7 to 16 ppm at site 1 (perched water at 1.5 m) and 2 to 41 ppm at site 2 (ground water at 0.9 m). Maximum concentrations, found in summer, were essentially the same as the average for total N in the input wastes (16 ppm at site 1 and 38 ppm at site 2). Nitrate was stable in the percolation stream below the root zone. Annual additions to subsurface waters were estimated at 76% of input N at site 1 and 65% at site 2. The range of PO₄-P in subsurface waters was 0.5 to 1.5 ppm at site 1 and 0.04 to 1.8 ppm at site 2; average waste water concentrations were 3 and 35 ppm. The highest concentrations in subsurface water were found in spring. Annual subsurface discharge was estimated at 27% of input P at site 1 and 2% at site 2. The extensive removals of PO₄ and the similar concentrations encountered in subsurface waters are of theoretical and practical interest since PO₄-P had already accumulated in soil profiles at both sites in quantities which exceed the Langmuir maxima for nonirrigated control soils. During seasons of major irrigation input, NO₃ appeared in subsurface waters in concentrations exceeding public health standards; PO₄ concentrations exceeded environmental guidelines at all times except where irrigation was discontinued during the winter at site 2. Soil systems appeared poised to discharge at the observed rates because of the large quantities of organic N and fixed P which had accumulated in the profiles over 20 years operation at site 1, and 10 years at site 2. The rate of residual accumulation in soil could have been reduced by harvest, to extend system life materially. The harvest potential of three grass clippings per season removed for silage, was estimated experimentally at 31% of input N at both sites and 80% of input PO₄ at site 1; 27% at site 2.
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