Determination of Young Olive-Tree Water Consumption with Drainage Lysimeters

Information about olive-tree irrigation in sub-humid climates, as in Uruguay, is scarce. Water consumption of young olive trees, Arbequina variety, was measured for two years with six drainage lysimeters, protected from rain by an automatic rain-out shelter. Irrigation water volume and drainage of each lysimeter were measured daily and soil moisture was registered twice a week with neutron probe at four depths. Evapotranspiration (ETc) was calculated by volume balance. Data periods when available water descended below 50% or increased over 100% were eliminated, as those in which the stem water potential was below -1.5 MPa. Water consumption values were averaged within 7- to 14-day periods, expressed in mm·d-1, and referred to a 2.5 × 5.5 m plantation framework without vegetation cover. There was a positive linear relation of the summer crop coefficient (Kc mid) with age, canopy cover percentage and canopy volume. Canopy cover percentage was the parameter which explained most of the variation of Kc mid, which ranged between 0.13 and 0.24, with 5% and 46% canopy cover, respectively. Full irrigation, associated to a good drainage resulted in a rapid growth of the young plants, bringing forward the start of full production period. This represents useful information for the adjustment of irrigation in olive-tree orchards, to accelerate growth with a rational and sustainable use of both water and energy in Uruguay.

Response of Soil Microbial Community to a High Dose of Fresh Olive Mill Wastewater

An incubation experiment was designed in order to determine the further microbiological response to an addition (500m^3 ha^(-1) ) of fresh olive mill wastewater (FOMWW) in a soil that has been frequently amended with uncontrolled doses of OMWW since the 1990s in an active disposal site (ADS soil). To achieve this aim, the phospholipid fatty acid (PLFA) profiles, microbial biomass C (C_(mic)), and dehydrogenase (DHA) and urease activities (URA) were monitored at the beginning (T_0), 3 h (T_1) and 97 d (T_f, i.e., the end) of incubation after FOMWW addition. After the FOMWW addition, an increase in the ratio of fungal to bacterial PLFAs was observed in ADS soil. Moreover, a relative increase of monounsaturated fatty acids (MUFAs) with respect to saturated fatty acids (SATFA) was found in the ADS soil. An increase of the Gram-positive to Gram-negative ratio was observed in this soil at the end of the incubation. While DHA and C_(mic) increased in the ADS soil after FOMWW addition, URA showed a decrease. Fungi and Gram-positive bacterial biomass experienced an increase after addition of a high dose of FOMWW in laboratory conditions.

Generation of high energy laser-driven electron and proton sources with the 200 TW system VEGA 2 at the Centro de Laseres Pulsados

The Centro de Laseres Pulsados in Salamanca,Spain has recently started operation phase and the first user access period on the 6 J 30 fs 200 TW system(VEGA 2)already started at the beginning of 2018.In this paper we report on two commissioning experiments recently performed on the VEGA 2 system in preparation for the user campaign.VEGA 2 system has been tested in different configurations depending on the focusing optics and targets used.One configuration(long focal length F=130 cm)is for underdense laser-matter interaction where VEGA 2 is focused onto a low density gas-jet generating electron beams(via laser wake field acceleration mechanism)with maximum energy up to 500 MeV and an X-ray betatron source with a 10 keV critical energy.A second configuration(short focal length F= 40 cm)is for overdense laser-matter interaction where VEGA 2 is focused onto a 5 μm thick Al target generating a proton beam with a maximum energy of 10 MeV and temperature of 2.5 MeV.In this paper we present preliminary experimental results.