LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

GROUP 2, SESSION A: CARBON OR WATER FOOTPRINTS, SOIL, BIODIVERSITY 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
62. Irrigation systems used in water scarce locations: LCA of three
contrasted scenarios for watermelon growing
Ludivine Pradeleix 1,* , Sami Bouarfa 1 , Philippe Roux 2 , M. Gueguen 2 , V. Bellon-Maurel 2
1 Cemagref/Irstea, Research Unit: G-Eau, Water management, stakeholders and uses, 361 rue JF Breton,
34196 Montpellier, France, 2 Cemagref/Irstea, Research Unit: Information & technologies for agroprocesses,
361 rue JF Breton, 34196 Montpellier, France, Corresponding author. E-mail: ludivine.pradeleix@irstea.fr
The agricultural productivity in arid and semi-arid regions greatly depends upon the access to irrigation. But
irrigated areas are often charged with being water and chemical inputs intensive and consequently damaging
the environment. In return, irrigated systems allow more diversified and intensified agricultural production.
This is even more important when farmers shift from surface irrigation to drip irrigation that enable covered
crops cultivation and use of mulch.
Environmental impacts arising from this twofold intensification process have to be addressed. Most of the
LCA studies and guidelines have targeted temperate locations (Nemecek & Kägi, 2007) and this study contribute
to adapt the method to southern contexts where the great variability of crop management practices
leads to increased uncertainty (Basset-Mens, et al., 2006).
Based on a case study located in the Tunisian central Irrigated Plain of Kairouan, we choose to study the
impacts per kg and per ha of three contrasted cropping systems of watermelon growing. They were identified
among a typology of eight systems in total. The least intensive cropping system relies on surface irrigation
rather than drip irrigation for the middle and high inputs intensive cropping systems. The most intensive
cropping system combines plastic mulches and row covers. Because it was not possible to measure irrigation
water volumes, they were modeled with PILOTE, a crop-soil model (Mailhol, 2004).
The most impacting cropping system per kg is the middle input intensive for almost all the impacts categories
apart from those related to toxicity and ecotoxicity. Then comes the high input intensive cropping system
whose impacts are balanced by the relative high yield obtained. The low input intensive system shows the
smallest impacts either per kg or ha.
The drip irrigation equipment at field scale is drawn on Fig. 1, and Fig. 2 displays the environmental impacts
of 1 ha of drip irrigated middle input intensive watermelon growing. The most impacting field operation
are fertilisation then irrigation and lastly soil preparation. More specific results of impacts caused by
the drip irrigation device show the relatively high impact of energy for water pumping and thus suggest
the related improvements be done.
References
Basset Mens, C., Van der Werf, H.M.G., Durand P., Leterme P., 2006. Implications of uncertainty and variability
in the life cycle assessment of pig production systems. International Journal of Life Cycle Assessment,
11(5), 298-304.
Mailhol, J. 2004. Analysis of irrigation systems and irrigation strategies for durum wheat in Tunisia. Agricultural
Water Management, 70(1), 19-37.
Nemecek, T., Kägi, T. 2007. Life Cycle Inventories of Agricultural Production Systems, (15).
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