Browsing by Subject "VITICULTURE"

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  • Russo, V.; Strever, A. E.; Ponstein, Helena J. (2021)
    Purpose Following the urgency to curb environmental impacts across all sectors globally, this is the first life cycle assessment of different wine grape farming practices suitable for commercial conventional production in South Africa, aiming at better understanding the potentials to reduce adverse effects on the environment and on human health. Methods An attributional life cycle assessment was conducted on eight different scenarios that reduce the inputs of herbicides and insecticides compared against a business as usual (BAU) scenario. We assess several impact categories based on ReCiPe, namely global warming potential, terrestrial acidification, freshwater eutrophication, terrestrial toxicity, freshwater toxicity, marine toxicity, human carcinogenic toxicity and human non-carcinogenic toxicity, human health and ecosystems. A water footprint assessment based on the AWARE method accounts for potential impacts within the watershed. Results and discussion Results show that in our impact assessment, more sustainable farming practices do not always outperform the BAU scenario, which relies on synthetic fertiliser and agrochemicals. As a main trend, most of the impact categories were dominated by energy requirements of wine grape production in an irrigated vineyard, namely the usage of electricity for irrigation pumps and diesel for agricultural machinery. The most favourable scenario across the impact categories provided a low diesel usage, strongly reduced herbicides and the absence of insecticides as it applied cover crops and an integrated pest management. Pesticides and heavy metals contained in agrochemicals are the main contributors to emissions to soil that affected the toxicity categories and impose a risk on human health, which is particularly relevant for the manual labour-intensive South African wine sector. However, we suggest that impacts of agrochemicals on human health and the environment are undervalued in the assessment. The 70% reduction of toxic agrochemicals such as Glyphosate and Paraquat and the 100% reduction of Chlorpyriphos in vineyards hardly affected the model results for human and ecotoxicity. Our concerns are magnified by the fact that manual labour plays a substantial role in South African vineyards, increasing the exposure of humans to these toxic chemicals at their workplace. Conclusions A more sustainable wine grape production is possible when shifting to integrated grape production practices that reduce the inputs of agrochemicals. Further, improved water and related electricity management through drip irrigation, deficit irrigation and photovoltaic-powered irrigation is recommendable, relieving stress on local water bodies, enhancing drought-preparedness planning and curbing CO2 emissions embodied in products.
  • Rey-Carames, Clara; Tardaguila, Javier; Sanz-Garcia, Andres; Chica-Olmo, Mario; Diago, Maria P. (2016)
    Precision viticulture requires the characterisation of the spatio-temporal variability of the vineyard status to design the appropriate management for each area. The goal of this work was to characterise the spatio-temporal variability of leaf chlorophyll (Chl) and nitrogen (N) content and their relationship with the vegetative growth in a three ha commercial vineyard (Vitis vinifera L.) using a geostatistical approach. Leaf Chl and N contents were assessed by two fluorescence indices provided by a hand-held fluorescence sensor. Fluorescence measurements were taken along five dates, from veraison to harvest, on 72 sampling points delineated on a regular grid across the vineyard. Shoot pruning weight (SPW) was measured for each sampling point as indicator of the grapevine vegetative growth. Geostatistical analysis was applied to model the spatial variability of leaf Chl and N content and SPW. The spread showed an increase of the variability of leaf Chl and N content during the ripening period, reaching maximum values prior to harvest. The variograms illustrated a similarity of the spatial variability structure of leaf Chl at all timings, unlike N which showed changing spatial variability structures along the ripening period. The Kappa index evidenced a slight intra-season stability for both Chl and N and showed that N could not be used alone as an indicator to delineate vigour management areas. The existence of spatio-temporal variability of key vegetative components was proved and its knowledge is crucial to implement precision viticulture approach such as variable rate application of fertilizers or water as needed. (C) 2016 IAgrE. Published by Elsevier Ltd. All rights reserved.