COPERNICUS SENTINEL-2 DATA FOR THE DETERMINATION OF GROUNDWATER WITHDRAWAL IN THE MAGHREB REGION

Agriculture plays an important role in the economy of the Maghreb region. Most of the water needed for irrigation comes from pumping of the aquifers. A controlled pumping of the groundwater resources does not exist yet, thus, estimating the total water consumption for agricultural use only with in situ data is nearly impossible. In order to overcome this lack of information, Copernicus data are used for determining the groundwater withdrawal through agriculture in the Maghreb region. This paper presents an approach for estimating and monitoring crop water requirements in Tunisia based on multitemporal Sentinel-2 data. Using this multitemporal information, a thorough analysis of the different culture types over time is possible, from which a set of additional multitemporal features is deduced for crop type classification. In this paper, the contribution of those features is analyzed, showing a classification accuracy enhanced by 10 % with the multitemporal features. Furthermore, relying on existing methods and FAO standards for the estimation of crop water needs, the methodology aims to estimate the specific crop water consumption. The results of the water estimates are validated against delimited areas where estimates of the water consumption are available from the authorities. Finally, as the study is conducted within the framework of an international technical cooperation, the methodology aims to be reproducible and sustainable for local authorities. The particularity of the results presented here is that they are achieved through automatic processing and using exclusively Open Source solutions, deployable on simple workstations

The Olive Mills Waste Water (OMW) as an Organic Amendment for Controlling Wind Erosion in Southern Tunisia by Improving the Soil Surface Structure

Abstract: Spraying OMW on poor sandy soils in the olive orchards induces increasing of the organic matter content, the formation of aggregates and improving the soil structure stability. Hence, OMW can be an alternative and effective way to control this polluting sewage. Since 1995 a field experiment is running in an olive plot in chammakh-Zarzis, south Tunisia, where rates of 50, 100 and 200 m 3 of OMW were sprayed yearly on 1 ha fields with 16 olives trees per ha. Data collected in 2006 showed an increase in organic matter content from originally 0.06 to 1.27 %, an increase in the amount of aggregates > 2 mm to 34%, and an increase in the threshold friction velocity for deflation to 12 m sec -1 for the 200 m 3 ha -1 application

Olive Mill Wastewater for Degraded Soil Restoration

In Southern Tunisian arid regions, the main issues of soil degradation on the surface by wind erosion (loss of nutrients and organic matter) and in depth by reduction of water reserves were diagnosed. In order to preserve these soils, improve biological activity and maintain their productivity, a restitution of organic amendments becomes necessary. Among the remedial solutions, the composting of olive tree by-products (Olive Mill Wastewater (OMW), Ramial Chipped Wood (RCW)) could be used for these soils. In this context, an experiment in pots was carried out on Medicago sativa L. in order to evaluate the effects of compost on ecosystem services of a sandy soil sampled from an experimental olive orchard in Chammakh. Two treatments (OMW with RCW and RCW) were applied and compared to a control soil having a sandy texture, with %sand being at least equal to 80%. The results showed that the highest nitrogen content is recorded with the composite compost (OMW with RCW) (0.26 g kg-1). The Electric Conductivity of treated soil decreased by 60% over time. The RCW was the most effective treatment for improving soil phosphorus properties and above-ground biomass. The OMW combined with RCW compost allowed to keep almost the same soil moisture (147.23 g kg-1) but almost 3 times more compared to a control soil (52.30 g kg-1).</jats:p

Space-based tools for surveillance of natural resources: thematic mapp

International audienc

Outils de surveillance des ressources naturelles à l’échelle spatiale : cartographie thématique

International audienc

Occurrence and functional diversity of bacteria in rhizosphere of citrus trees infested by Tylenchulus semipenetrans in a citrus-growing area of Tunisia

Tylenchulus semipenetrans is a major plant-parasitic nematode pest of citrus which readily infests sour orange rootstock Citrus aurantium. In order to examine the bacterial diversity and prevalence in the nematode infested citrus rhizosphere, 282 bacterial strains were isolated from roots of mature citrus trees, from egg masses of T. semipenetrans, and from nematophagous fungi in the orange producing area Cap bon in Tunisia. The rhizosphere of citrus had a high diversity of bacterial strains among the 20 agricultural parcels. According to morphological and biochemical characteristics, sixty bacteria strains were selected to explore the diversity of biological activity. None of the bacterial strains considered in this study have phytopathogenic activity. Each strain was identified and tested as a potential natural antagonist against fungi and against citrus nematode (egg hatching and juvenile mortality). Bacillus cereus, B. mycoides, B. pumilus and B. thuringiensis were the four most abundant species regardless the sampling location. Canonical discriminant analysis grouped the bacteria into five groups of biological activities: Group A, similar to water control, had not specific effect. Group B showed strong effect, and group C caused moderate growth inhibition of the nematophagous fungi Monacrosporium cianopagum CBM. Group C had stronger growth inhibition of the fungus Arthrobotrys conoides RGA than groups B and D. Groups D and E showed a strong activity on nematode egg hatch inhibition.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Life and death in rhizosphere of Citrus: antifungal activities of bacterial strains in Tunisian agricultural soils

info:eu-repo/semantics/nonPublishe