94 resultados para Nitrogen productivity
em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain
Resumo:
Further knowledge of the processes conditioning nitrogen use efficiency (NUE) is of great relevance to crop productivity. The aim of this paper was characterise C and N partitioning during grain filling and their implications for NUE. Cereals such as bread wheat (Triticum aestivum L. cv Califa sur), triticale (× Triticosecale Wittmack cv. Imperioso) and tritordeum (× Tritordeum Asch. & Graebn line HT 621) were grown under low (LN, 5 mm NH4NO3) and high (HN, 15 mm NH4NO3) N conditions. We conducted simultaneous double labelling (12CO2 and 15NH415NO3) in order to characterise C and N partitioning during grain filling. Although triticale plants showed the largest total and ear dry matter values in HN conditions, the large investment in shoot and root biomass negatively affected ear NUE. Tritordeum was the only genotype that increased NUE in both N treatments (NUEtotal), whereas in wheat, no significant effect was detected. N labelling revealed that N fertilisation during post-anthesis was more relevant for wheat and tritordeum grain filling than for triticale. The study also revealed that the investments of C and N in flag leaves and shoots, together with the"waste" of photoassimilates in respiration, conditioned the NUE of plants, and especially under LN. These results suggest that C and N use by these plants needs to be improved in order to increase ear C and N sinks, especially under LN. It is also remarkable that even though tritordeum shows the largest increase in NUE, the low yield of this cereal limits its agronomic value.
Resumo:
The present paper aims at analyzing the sources of productivity in Europe to account for its recent underperformance and identify potential geographic idiosyncracies. We study the productivity performance and its sources in a sample of ten European regions belonging to four countries (France, Germany, Italy and Spain). Exploiting the increasing availability of disaggregated data at regional level in Europe, we propose both a descriptive statistics and an econometric analysis of productivity sources since 1995. Our main finding is that the sources of labor productivity are rather heterogeneous across our sample but may be associated with regional or national idiosyncracies.
Resumo:
Understanding the mechanism through which financial globalization affects economic performance is crucial for evaluating the costs and benefits of opening financial markets. This paper is a first attempt at disentangling the effects of financial integration on the two main determinants of economic performance: productivity (TFP) and investments. I provide empirical evidence from a sample of 93 countries observed between 1975 and 1999. The results suggest that financial integration has a positive direct effect on productivity, while it spurs capital accumulation only with some delay and indirectly, since capital follows the rise in productivity. I control for indirect effects of financial globalization through banking crises. Such episodes depress both investments and TFP, though they are triggered by financial integration only to a minor extent.
Resumo:
The Spanish savings banks attracted quite a considerable amount of interest within the scientific arena, especially subsequent to the disappearance of the regulatory constraints during the second decade of the 1980s. Nonetheless, a lack of research identified with respect to mainstream paths given by strategic groups, and the analysis of the total factor productivity. Therefore, on the basis of the resource-based view of the firm and cluster analysis, we make use of changes in structure and performance ratios in order to identify the strategic groups extant in the sector. We attain a threeways division, which we link with different input-output specifications defining strategic paths. Consequently, on the basis of these three dissimilar approaches we compute and decompose a Hicks-Moorsteen total factor productivity index. Obtained results put forward an interesting interpretation under a multi-strategic approach, together with the setbacks of employing cluster analysis within a complex strategic environment. Moreover, we also propose an ex-post method of analysing the outcomes of the decomposed total factor productivity index that could be merged with non-traditional techniques of forming strategic groups, such as cognitive approaches.
Resumo:
El present treball pretén avaluar l’impacte de les activitats agràries sobre les aigües subterrànies, al Baix Empordà. La ramaderia intensiva genera uns residus que l’agricultura no és capaç d’assumir. Els excedents generats s’infiltren al subsòl, generalment en forma de nitrats (NO3-), provocant la contaminació de les aigües subterrànies. Aquesta pot provocar greus problemes ecològics en els sistemes aquàtics, i afectar a la salut humana. S’ha realitzat un balanç de nitrogen per a les zones agrícoles de l’àrea d’estudi, avaluant els diversos processos que incorporen o extreuen nitrogen al sòl. Paral·lelament, s’ha estudiat el consum d’aigua provocat pel diversos sectors presents a la zona d’estudi, per tal d’avaluar quantitativament la pressió que provoquen sobre els aqüífers. Els resultats obtinguts mostren que la majoria de municipis estudiats generen excedents de nitrogen, justificant la presència de nitrats al subsòl.
Resumo:
This study examines the evolution of labor productivity across Spanish regions during the period from 1977 to 2002. By applying the kernel technique, we estimate the effects of the Transition process on labor productivity and its main sources. We find that Spanish regions experienced a major convergence process in labor productivity and in human capital in the 1977-1993 period. We also pinpoint the existence of a transition co-movement between labor productivity and human capital. Conversely, the dynamics of investment in physical capital seem unrelated to the transition dynamics of labor productivity. The lack of co-evolution can be addressed as one of the causes of the current slowdown in productivity. Classification-JEL: J24, N34, N940, O18, O52, R10
Resumo:
This paper explores the effects of two main sources of innovation -intramural and external R&D- on the productivity level in a sample of 3,267 Catalonian firms. The data set used is based on the official innovation survey of Catalonia which was a part of the Spanish sample of CIS4, covering the years 2002-2004. We compare empirical results by applying usual OLS and quantile regression techniques both in manufacturing and services industries. In quantile regression, results suggest different patterns at both innovation sources as we move across conditional quantiles. The elasticity of intramural R&D activities on productivity decreased when we move up the high productivity levels both in manufacturing and services sectors, while the effects of external R&D rise in high-technology industries but are more ambiguous in low-technology and knowledge-intensive services. JEL codes: O300, C100, O140. Keywords: Innovation sources, R&D, Productivity, Quantile regression
Resumo:
En aquest estudi es realitzà eliminació biològica simultània de fòsfor i nitrogen en un Reactor Discontinu Seqüencial (SBR), el qual conté una biomassa enriquida amb Organismes Desnitrificadors Acumuladors de Fòsfor (DPAO) que utilitzen com a única font de carboni l’àcid propiònic i com acceptors d’electrons: nitrit en la fase anòxica i oxigen en l’aeròbica. L’SBR opera amb cicle de 8 h alternant fase anaeròbica, anòxica i aeròbica. El seguiment del sistema es realitzà mitjançant mesures on-line (titrimetria) i off-line (quantificació d’àcid propiònic, nitrit i fòsfor), utilitzant l’HPLC per quantificar l’àcid propiònic i cromatografia iònica per les mesures de nitrit i fòsfor. Amb aquest sistema es pretén augmentar la captació de fòsfor en la fase anòxica fet que s’aconseguí realitzant diferents canvis al reactor per tal de maximitzar el consum de nitrit en aquesta fase, ja fos allargant el temps de fase o augmentant la concentració de biomassa. Aquest experiment ha suposat un augment de la captació de fòsfor (33 mg P-PO4 3-/L), de l’eliminació neta de fòsfor (17 mg P-PO4 3-/L) i de consum de nitrit (27 mg N-NO2-). Per altra banda, es pretenia veure els efectes a curt termini de l’eliminació de la fase aeròbica a partir del seguiment de 2 cicle puntuals i d’un cicle de 32 h sense fase aeròbica. En ambdós casos s’aconseguí una eliminació neta de fòsfor.
Resumo:
This paper analyses the performance of companies’ R&D and innovation and the effects of intra- and inter-industry R&D spillover on firms’ productivity in Catalonia. The paper deals simultaneously with the performance of manufacturing and service firms, with the aim of highlighting the growing role of knowledge-intensive services in promoting innovation and productivity gains. We find that intra-industry R&D spillovers have an important effect on the productivity level of manufacturing firms, and the inter-industrial R&D spillovers related to computer and software services also play an important role, especially in high-tech manufacturing industries. The main conclusion is that the traditional classification of manufactured goods and services no longer makes sense in the ‘knowledge economy’ and in Catalonia the regional policy makers will have to design policies that favour inter-industrial R&D flows, especially from high-tech services.
Resumo:
This paper explores the effects of two main sources of innovation —intramural and external R&D— on the productivity level in a sample of 3,267 Catalan firms. The data set used is based on the official innovation survey of Catalonia which was a part of the Spanish sample of CIS4, covering the years 2002-2004. We compare empirical results by applying usual OLS and quantile regression techniques both in manufacturing and services industries. In quantile regression, results suggest different patterns at both innovation sources as we move across conditional quantiles. The elasticity of intramural R&D activities on productivity decreased when we move up the high productivity levels both in manufacturing and services sectors, while the effects of external R&D rise in high-technology industries but are more ambiguous in low-technology and services industries.
Resumo:
This paper investigates the extent to which the gap in total factor productivity between small and large firms is due to differences in the endowment of factors determining productivity and to the returns associated with these factors. We place particular emphasis on the contribution of differences in the propensity to innovate and in the use of skilled labor across firms of different size. Empirical evidence from a representative sample of Spanish manufacturing firms corroborates that both differences in endowments and returns to innovation and skilled labor significantly contribute to the productivity gap between small and large firms. In addition, it is observed that the contribution of innovation to this gap is caused only by differences in quantity, while differences in returns have no effect; in the case of human capital, however, most of the effect can be attributed to increasing differences in returns between small and large firms.
Resumo:
This paper addresses the issue of the relationship between productivity and market competition. In comparison to the economies of other European countries, the Spanish economy has been growing, while productivity growth has stagnated. Here we provide empirical evidence about the relationship between productivity and market competition from Spanish manufacturing firms at firm level between 1994 and 2004. Correcting for selection bias, our study pays special attention to the patterns of productivity growth between openness and non-openness firms. When market competition increases the effect on firms operating in domestic markets is positive but when the level of competition is high incentives to invest in innovation and productivity gains disappear. The empirical relationship between competition and productivity is an inverted U-shape, where productivity growth is highest at intermediate levels of competition. The productivity growth of firms operating in international markets is higher than that of non-openness firms, but when market competition rises they moderate their productivity growth. Our empirical results suggest that the correct competition policy in the Spanish economy should remove the barriers to competition in internal markets in order to increase the incentives for manufacturing firms to invest in innovation and productivity growth.
Resumo:
This paper analyses the differential impact of human capital, in terms of different levels of schooling, on regional productivity and convergence. The potential existence of geographical spillovers of human capital is also considered by applying spatial panel data techniques. The empirical analysis of Spanish provinces between 1980 and 2007 confirms the positive impact of human capital on regional productivity and convergence, but reveals no evidence of any positive geographical spillovers of human capital. In fact, in some specifications the spatial lag presented by tertiary studies has a negative effect on the variables under consideration.
Resumo:
R&D investment is an important driver of productivity gains. However, firms differ in their ability to appropiate the returns to their R&D efforts. This paper analyses to what extent firm's internationalization influences the endogenous relation between R&D and productivity. In particular, we assess the contribution of R&D to productivity for a panel of UK firms that differ in their degree of internationalization. We find that, on average, multinationals obtain higher gains from their investment in R&D. However, the influence of internationalization on the contribution of R&D to productivity varies along the distribution of the returns to R&D. Keywords: R&D, Multinationals, Productivity. JEL Codes: C14, D24, F23.
Resumo:
This paper explores the effects of two main sources of innovation - intramural and external R&D— on the productivity level in a sample of 3,267 Catalonian firms. The data set used is based on the official innovation survey of Catalonia which was a part of the Spanish sample of CIS4, covering the years 2002-2004. We compare empirical results by applying usual OLS and quantile regression techniques both in manufacturing and services industries. In quantile regression, results suggest different patterns at both innovation sources as we move across conditional quantiles. The elasticity of intramural R&D activities on productivity decreased when we move up the high productivity levels both in manufacturing and services sectors, while the effects of external R&D rise in high-technology industries but are more ambiguous in low-technology and knowledge-intensive services. JEL codes: O300, C100, O140 Keywords: Innovation sources, R&D, Productivity, Quantile Regression