SPFC: a tool to improve water management and hay production in the Crau region

Correspondance: [email protected] ; UMR SYSTEM équipe CONSYSTThis article deals with the development and application of SPFC, a model used to improve water and grassland production (HC) in this region of France. This model is composed of two sub-models: an irrigation model and a crop model. As the fields are border irrigated, these two sub-models are coupled. The crop model simulates dry matter, Leaf Area Index (LAI) and soil water reserve (SWR) variations. LAI and SWR are both used for border model updating: SWR for the deficit of saturation required by the infiltration equation and LAI for the roughness coefficient n. After calibration and validation, SPFC is then used to identify realistic management strategies for the irrigation and production system at the plot level. By scheduling irrigation when SWR is 50% depleted, would result in a low Dry Matter DM production loss (around 10%), reduced labour (8 irrigation events instead of 11) and in significant water saving compared with farmers' practices, on the basis of an average climatic scenario. Furthermore, this improvement of irrigation efficiency is not incompatible with groundwater recharge used for the potable water supply of the region

Effect of water stress on growth, water consumption and yield of silage maize under flood irrigation in semi-arid clilmate of Tadla (Morocco)

The field study of crops response to water stress is important to reduce agricultural water use in areas where the water resources are limited. This study was carried out during two growing periods of 2009 and 2010 in order to study the effect of water stress on crops growth, water consumption and dry matter yield of silage maize supplied with flood irrigation under the semiarid climate of Tadla in Morocco. Four to five irrigation treatments were applied at the rates of 100, 80, 60, 40 and 20% of ETc of maize. Soil water status, crop growth, leaf area index and above-ground biomass were measured. Results showed that growth dynamic of maize passes by three distinct phases: exponential phase, linear phase and a final phase. The irrigation deficit accelerates the senescence of the sheets and reduces the leaf area index. The maximum values of this parameter reached at flowering under the full irrigation treatment (100%ETc) are 5.1 and 4.8 in 2009 and 2010 respectively. Dry matter yields varied from 5.3 t/ha under T4 (40%ETc) to 16.4 t/ha under T1 (100% ETc) in 2009 whereas in 2010, it oscillated between 3.9 t/ha under T5 (20%ETc) to 12.5 t/ha under T1 (100%ETc). The actual evapotranspiration under T1 (100%ETc) was 478 mm and 463 mm in 2009 and 2010 respectively. According to the averaged values of two years, linear relationships have been evaluated between dry matter yield and water consumption ETa. Yield response factor (ky) for the silage maize for all growth season was 1.12

Synthesis, Molecular Editing, and Biological Assessment of the Potent Cytotoxin Leiodermatolide

It was by way of total synthesis that the issues concerning the stereostructure of leiodermatolide (1) have recently been solved; with the target now being unambiguously defined, the mission of synthesis changes as to secure a meaningful supply of this exceedingly scarce natural product derived from a deep-sea sponge. To this end, a scalable route of 19 steps (longest linear sequence) has been developed, which features a catalytic asymmetric propargylation of a highly enolizable β-keto-lactone, a ring closing alkyne metathesis and a modified Stille coupling as the key transformations. Deliberate digression from this robust blueprint brought a first set of analogues into reach, which allowed the lead qualities of 1 to be assessed. The acquired biodata show that 1 is a potent cytotoxin in human tumor cell proliferation assays, distinguished by GI50 values in the ≤3 nM range even for cell lines expressing the Pgp efflux transporter. Studies with human U2OS cells revealed that 1 causes mitotic arrest, micronucleus induction, centrosome amplification and tubulin disruption, even though no evidence for direct tubulin binding has been found in cell-free assays; moreover, the compound does not seem to act through kinase inhibition. Indirect evidence points at centrosome declustering as a possible mechanism of action, which provides a potentially rewarding outlook in that centrosome declustering agents hold promise of being inherently selective for malignant over healthy human tissue

Disentangling the complexity of groundwater dependent social-ecological systems

Groundwater resources are part of larger social-ecological systems. In this chapter, we review the various dimensions of these complex systems in order to uncover the diversity of elements at stake in the evolution of an aquifer and the loci for possible actions to control its dynamics. Two case studies illustrate how the state of an aquifer is embedded in a web of biophysical and sociopolitical processes. We propose here a holistic view through an IGM-scape that describes the various possible pathways of evolution for a groundwater related social-ecological system. Then we describe the elements of this IGM-scape starting with physical entities and processes, including relations with surface water and quality issues. Interactions with society bring an additional layer of considerations, including decisions on groundwater abstraction, land use changes and even energy related choices. Finally we point out the policy levers for groundwater management and their possible consequences for an aquifer, taking into account the complexity of pathways opened by these levers

Allogeneic stem cell transplantation in second complete remission for core binding factor acute myeloid leukemia: a study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Core binding factor acute myeloid leukemia (AML) comprises two subtypes with distinct cytogenetic abnormalities of either t(8;21)(q22;q22) or inv(16)(p13q22)/t(16;16)(p13;q22). Since longterm response to chemotherapy in these leukemias is relatively good, allogeneic hematopoietic stem cell transplantation is considered in patients who relapse and achieve second complete remission. To evaluate the outcomes of allogeneic transplantation in this indication, we studied 631 patients reported to the European Society for Blood and Marrow Transplantation Registry between the years 2000 and 2014. Leukemia-free survival probabilities at two and five years were 59.1% and 54.1%, while overall survival probabilities were 65% and 58.2%, respectively. The incidence of relapse and risk of non-relapse mortality at the same time points were 19.8% and 22.5% for relapse and 20.9% and 23.3% for non-relapse mortality, respectively. The most important adverse factors influencing leukemia-free and overall survival were: leukemia with t(8;21), presence of three or more additional chromosomal abnormalities, and Karnofsky performance score <80. Relapse risk was increased in t(8;21) leukemia and associated with additional cytogenetic abnormalities as well as reduced intensity conditioning. Measurable residual disease in molecular evaluation before transplantation was associated with increased risk of relapse and inferior leukemia-free survival

Choix des paramètres d'arrosage en irrigation à la raie

The recent advances in surface irrigation in the South-East of France concern primarily modern systems and the use of tensiometric monitoring. The article presents additional researches undertaken on the hydraulic evaluation of watering quality in order to minimize water losses or to improve uniformity. / Les progrès récents de l'irrigation de surface dans le Sud-Est de la France concernent en premier lieu l'apparition de matériels modernes et l'utilisation du pilotage tensiométrique. L'article présente les recherches complémentaires entreprises sur l'évaluation hydraulique de la qualité des arrosages en vue de diminuer les pertes en eau ou d'améliorer l'uniformité

Impact of water application conditions on nitrogen leaching under furrow irrigation: Experimental and modelling approaches

Des tests d'infiltration locaux sur des raies bouchées de 1.5 m de longeur on été effectués en sol limoneux afin d'estimer le lessivage d'azote sous irrigation lorsque le fertilisant a été concentré sur la partie haute des billons lors du traçage des raies.Cet article ttreaite plus particulièrement de l'impact des hauteurs d'eau ou des doses infiltrées (DI) sur le déplacement d'azote dans 7 raie bouchées de 1.5 m de long. lors d'un premier arrosage, une DI de plus de 240 mm reduit significativement l'hétérogéneité du profil de concentration d'azote mesuré sous le billon et sous la raie. L'homogénété du profil d'azote entre raie et billon qui en résulte, permet la détermination du bilan d'azote au cours du cycle cultural à partir d'échantillons de sol prélevés en début et en fin de saison ainsi que dans le tissus végétal. Cela n'est pas possible lorsqu'il existe une hétérogénéité importante entre les 2 profils (sous raie et sous billon) à la fin de la saison comme on l'observe sur le traitementsoumis à des apports d'eau modérés.On constate qu'un apport d'eau important lors du premier arrosage n'induit, à une période où les besoins en azote sont élevés, n'affecte pas le rendement potentiel de la culture de maïs. Une modélisation adaptée au contexte 2D du transport d'eau et de solutés nous a permis de valider l'estimation du lessivage d'azote obtenu à partir de la méthode du bilan appliqué au traitement fortement irrigué. Environ 22 kg d'azote ont été lessivé sous la zone racinaire (soit 10% environde la dose de N apportée)au cours de la saison d'irrigation pour des apports d'eau élevés (240 mm pour la première irrigation et environ 200 mm pour les suivantes). La modélisation pourrait être un recours concenrnant l'estimation du lessivage d'azote sous conditions modérées d'apport d'eau en raison de la forte hétérogénéité des profils de distribution d'azote dans la zone racinaire / Local infiltration test on 1.5 blocked furrows were carried out on a loam soil to assess N fertliser leaching under furrow irrigation where ridging operations entails placing nitrogen on the upper part of thge ridge. This article focusses on the impact of flow depth or water application depths (WAD) on nitrogen movement in seven 1.5 m long blocked furrows. For a firts irrigation event , a WAD greater than or equal 240 mm significanlty reduced the heterogeneity of the N concentration profiles measured at the top of the ridge and beneath the furrow. The virtually homogenepus N soil distribution with depth permitted the determination of the nitrogen balance throughout the season using soil samples obtained at the beginnind and end of season as well as the determination of nitrogen present in the crop tissue. This is not possible when there is a heterogeneous N soil profile at the end of the irrigation season, as observed under moderate WAD conditions. In addition, a substantial WAD delivered during the firts irrigation, at a period wher the plant N requirements are high, does not affect crop yield potential. A modelling approache adapted to 2D water and solute transfer allow us to validate the estimated N leaching resulting from N balance performed under high WAD conditions. About 22 kg of N was leached behind the root zone (around 10% of the nitrogen applied) during the irrigation season under high WAD (240 mm during first irrigation and around 200mm for the following irriagtion evnts). Modelling should be used to estimate leaching under low WAD conditions because of the heterogeneous N distribution within the root zone