Nitrogen use efficiency and residual effect of fertilizers withnitrification inhibitors

Blending fertilizers with nitrification inhibitors (NI) is a technology to reduce nitrogen (N) losses. The application of NI could increase the soil N supply capacity over time and contribute to an enhancement of N-fertilizer recovery in some cropping systems. During two seasons, a field experiment with maize (Zea mays L.) was fertilized with ammonium sulfate nitrate (ASN) and DMPP (3,4 dimethylpyrazole phosphate) blended ASN (ENTEC) at two levels (130 and 170 kg N ha-1) under Mediterranean conditions. A control treatment with no added N fertilizer was also included. Maize yield, grain quality, nutritional state and fertilizer use efficiency were evaluated. Due to the observation of a soil residual effect, a non-fertilized sunflower (Helianthus annuus L.) was planted in the same plots to study the cumulative effect during a third experimental season. Laboratory determinations were performed in order to elucidate the possible sources of residual N. The second year, DMPP application allowed a 23% reduction of the fertilizer rate without decreasing crop yield or grain quality. In addition, the non-fertilized sunflower planted after the maize scavenge more N in treatments previously treated with ENTEC than with traditional fertilizers, increasing N use efficiency in the cropping systems. After DMPP application, N was conserved in non-ready soil available forms during at least one year and subsequently released to meet the sunflower crop demand. The potential N mineralization obtained from aerobic incubation under controlled conditions of soil samples collected before sunflower sowing was higher for ENTEC than ASN or control treatments. A higher δ15N in the soil indicated larger non-exchangeable NH4+ fixation in soils from the plots treated with ENTEC or ASN-170 than from the ASN-130 or the control. These results open the opportunity to increase N efficiency by designing crop rotations able to profit from the effect of NI on the soil residual N

Infancia, juventud y migraciones. Una mirada para la cooperación internacional

Depto. de Sociología AplicadaFac. de Ciencias Políticas y SociologíaTRUEpu

Modelos para el cálculo de consumo y emisiones gaseosas de la flota de autobuses de Madrid

En este trabajo se presentan algunos resultados del estudio experimental de cálculo de emisiones emanadas en condiciones concretas de la explotación del servicio de la flota de vehículos del transporte público de pasajeros de la ciudad de Madrid, realizado en el marco de cooperación entre grupos de investigación del Instituto Universitario de Investigación del Automóvil (INSIA) de la Universidad Politécnica de Madrid y del Instituto de Desarrollo Industrial (IIDISA) de la Universidad Nacional de Salta. La experiencia consistió en la adquisición de datos de emisiones de contaminantes y consumo de combustible mediante un equipo de medida de emisiones a bordo en un vehículo de prueba en condiciones reales de explotación, en los que se tomaron además, datos de variables cinemáticas en distintas líneas y recorridos representativos de las que conforman el servicio de la Empresa Municipal de Transportes de Madrid. Con los datos adquiridos se han ajustado modelos para la estimación de emisiones contaminantes y consumo en un escenario de 30 ciclos, con el objetivo de obtener valores por unidad (30 ciclos) que pueden ser utilizados como valores de referencia. Por razones de extensión, en este estudio se presentan los resultados del modelo estadístico para el cálculo del consumo y las emisiones totales de CO2 ajustado en función de variables cinemáticas como la velocidad media del autobús y el tiempo, en una de las líneas de servicio más largas de la ciudad: la línea Circular Uno (C1). Las expresiones obtenidas permiten estimar el consumo de combustibles y emisiones de CO2 con valores del coeficiente de correlación superior al 70%. A su vez, es posible realizar un análisis de la gestión de la flota de transporte inspirada en la comparación de los ciclos de operación de las líneas y la evaluación de los impactos producidos por la sustitución de vehículos y combustible

Maize diversification and nitrogen fertilization effects on soil nitrous oxide emissions in irrigated mediterranean conditions

Maize is a major irrigated crop in Mediterranean areas and its typical intensive management may impact soil nitrous oxide (N$_{2}$O) emissions. In these irrigated continuous maize systems, the legumes incorporation as well as adjusted nitrogen (N) fertilization might be interesting strategies to reduce soil N$_{2}$O emissions. The objective of this study was to assess the impact of cropping diversification and different N rates on soil N$_{2}$O emissions in flooded irrigated maize under Mediterranean conditions. To achieve this, two cropping systems (maize monoculture system, MC; and pea -maize rotation, MP) and 3N rates (unfertilized, 0N; medium rate, MN; and high rate, HN) were evaluated in a field experiment established in NE Spain during 2 years (2019; 2020). During the studied period, the N rate had a significant effect on soil N$_{2}$O emissions, with a non-linear positive response of cumulative soil N$_{2}$O emissions to N rates. In both systems, quick and high increases of soil N$_{2}$O fluxes were observed immediately after the N application reaching 55 and 100 mg N$_{2}$O-N m$^{−2}$ day$^{−1}$ in MC and MP, respectively. Both years, the pea phase of the MP rotation showed greater cumulative N2O emissions than the fallow of MC. However, N$_{2}$O losses in the maize phase were similar (2019) or even higher (2020) in MC than in MP. Moreover, in both seasons, the MN treatments showed lower yield-scaled N$_{2}$O emissions and N emission factor than the HN treatments, being this last lower than 1% in all cases. The results obtained showed that in irrigated Mediterranean conditions the replacement of a fallow by a legume, together with an adjusted N fertilization are favourable strategies to mitigate soil N$_{2}$O emissions in high-yielding maize systems

Sobre las colecciones burgalesas y otras europeas de Enrique Pérez Arbeláez (1896-1972), depositadas en el Herbario Nacional Colombiano, 3

About Spanish and other European plant collections of Enrique Pérez Arbeláez deposited in the Colombian National Herbarium. After a introduction dedicated to gloss the personality of the Colombian botanist, stopping in some biographical notes, a critical relationship is made on the 214 sheets of the Herbarium of Enrique Pérez Arbeláez. Collections in Europe, collected in Spain between 1922 and 1925, deposited in the Colombian National Herbarium (COL)

Monitoring maize N status with airborne and ground level sensors

The anaerobic digestion of food waste for energy recovery produces a nutrient-rich digestate which is a valuable source of crop available nitrogen (N). As with any ‘new’ material being recycled to agricultural land it is important to develop best management practices that maximise crop available N supply, whilst minimising emissions to the environment. The objective of this study was to measure N losses following application of food-based digestate, green/food compost and green compost to agricultural land via ammonia (NH3) volatilisation and nitrous oxide (N2O) emissions to air, and nitrate (NO3) leaching to water, and to compare these with losses from livestock manure (slurry and solids farmyard manure –FYM)

Heme oxygenase 1 and 2 common genetic variants and risk for essential tremor

Varios informes sugirieren que una función hemo oxigenasa 1 y 2 de los genes HMOX HMOX1 y 2 modifican el riesgo de desarrollar la enfermedad de Parkinson (EP). Porque el temblor esencial (ET) y PD comparten fenotipo y, probablemente, unos factores etiológicos semejantes, analizamos si tales genes están relacionados con el riesgo de desarrollar ET. Se analizó la distribución de las frecuencias genotípicas y alélicas de los HMOX1 rs2071746, HMOX1 rs2071747, HMOX2 rs2270363 y rs1051308 HMOX2 polimorfismos de nucleótido único, así como la presencia de variaciones de número de copias de estos genes en 202 sujetos con ET familiar y 747 controles sanos. Las frecuencias alélicas de rs2071746T y R1051308G ET fueron significativamente menores en los pacientes que en los controles. Ninguno de los polimorfismos estudiados influyeron en el comienzo de la enfermedad. El presente estudio sugiere una débil asociación entre HMOX1 rs2071746 y rs1051308 HMOX2 polimorfismo y el riesgo de desarrollar ET en la población española.Several reports suggested a role of heme oxygenase genes 1 and 2 (HMOX1 and HMOX2) in modifying the risk to develop Parkinson disease (PD). Because essential tremor (ET) and PD share phenotypical and, probably, etiologic factors of the similarities, we analyzed whether such genes are related with the risk to develop ET. We analyzed the distribution of allelic and genotype frequencies of the HMOX1 rs2071746, HMOX1 rs2071747, HMOX2 rs2270363, and HMOX2 rs1051308 single nucleotide polymorphisms, as well as the presence of copy number variations of these genes in 202 subjects with familial ET and 747 healthy controls. Allelic frequencies of rs2071746T and rs1051308G were significantly lower in ET patients than in controls. None of the studied polymorphisms influenced the disease onset. The present study suggests a weak association between HMOX1 rs2071746 and HMOX2 rs1051308 polymorphisms and the risk to develop ET in the Spanish population.T• Instituto de Salud Carlos III, Fondo de Investigación Sanitaria: Ayudas PI12/00241, PI12/00324 y RETICS RD12/0013/0002 • Junta de Extremadura: Ayuda GR10068 • Ministerio de Ciencia e Innovación: Ayudas SAF2006-10126 (2006–2009) y SAF2010-22329-C02-01 (2011–2013) • Parcialmente financiado Fondos FEDER – Fondo Europeo de Desarrollo RegionalpeerReviewe

Effect of cover crops on greenhouse gas emissions in an irrigated field under integrated soil fertility management

Agronomical and environmental benefits are associated with replacing winter fallow by cover crops (CC). Yet, the effect of this practice on nitrous oxide (N2O) emissions remains poorly understood. In this context, a field experiment was carried out under Mediterranean conditions to evaluate the effect of replacing the traditional winter fallow (F) by vetch (Vicia sativa L.; V) or barley (Hordeum vulgare L.; B) on greenhouse gas (GHG) emissions during the intercrop and the maize (Zea mays L.) cropping period. The maize was fertilized following Integrated Soil Fertility management (ISFM) criteria. Maize nitrogen (N) uptake, soil mineral N concentrations, soil temperature and moisture, dissolved organic carbon (DOC) and GHG fluxes were measured during the experiment. Our management (adjusted N synthetic rates due to ISFM) and pedo-climatic conditions resulted in low cumulative N2O emissions (0.57 to 0.75 kg N2O-N ha-1 yr-1), yield-scaled N2O emissions (3-6 g N2O-N kg aboveground N uptake-1) and N surplus (31 to 56 kg N ha-1) for all treatments. Although CCs increased N2O emissions during the intercrop period compared to F (1.6 and 2.6 times in B and V, respectively), the ISFM resulted in similar cumulative emissions for the CCs and F at the end of the maize cropping period. The higher C:N ratio of the B residue led to a greater proportion of N2O losses from the synthetic fertilizer in these plots, when compared to V. No significant differences were observed in CH4 and CO2 fluxes at the end of the experiment. This study shows that the use of both legume and non-legume CCs combined with ISFM could provide, in addition to the advantages reported in previous studies, an opportunity to maximize agronomic efficiency (lowering synthetic N requirements for the subsequent cash crop) without increasing cumulative or yield-scaled N2O losses