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Índice de la presentación: 1. Origen y objetivos del proyecto. 2. Consulta a los miembros de la SECS: encuesta y resultados. 3. Futuro y continuidad del proyecto., Objetivos de la Edafoteca Nacional: 1. Conservar a largo plazo muestras de suelo representativas de los principales suelos españoles (y los datos disponibles de las mismas). 2. Poner dichas muestras y datos a disposición de la comunidad científica en una única sede o en varias sedes (edafoteca con “estructura en red”).

Maize is a major irrigated crop in Mediterranean areas and its typical intensive management may impact soil nitrous oxide (N2O) emissions. In these irrigated continuous maize systems, the legumes incorporation as well as adjusted nitrogen (N) fertilization might be interesting strategies to reduce soil N2O emissions. The objective of this study was to assess the impact of cropping diversification and different N rates on soil N2O 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 N2O emissions, with a non-linear positive response of cumulative soil N2O emissions to N rates. In both systems, quick and high increases of soil N2O fluxes were observed immediately after the N application reaching 55 and 100 mg N2O-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, N2O 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 N2O 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 N2O emissions in high-yielding maize systems.

In croplands, the adoption of certain management practices may increase soil organic carbon (SOC) levels. In this study, we evaluated the short-term impact of crop stover management and the interaction between crop stover and irrigation method on SOC change in a continuous maize (Zea mays L.) system in Spain. Four years after the beginning of the experiment, total SOC and C fractions (particulate organic matter carbon, POM-C; and mineral-associated organic matter carbon, Min-C) contents, SOC stocks and SOC stock changes were measured in four different soil layers (0−5, 5−10, 10−25 and 25−50 cm) in an experiment with two irrigation methods (sprinkler and flood) and three stover management systems (conventional tillage with all the stover incorporated, CT; no-tillage maintaining the stover, NTr; and no-tillage removing the stover, NT). Stover management resulted in significant differences in SOC and POM-C but not in Min-C. In particular, NT reduced SOC and POM-C contents compared with CT and NTr (about 10 and 60 %, respectively). After 4 years, SOC change was not affected by the interaction between stover management and irrigation. Concurrently, both CT and NT showed SOC losses, reaching 0.11 and 1.22 Mg ha−1 yr−1 in CT and NT, respectively. However, NTr showed SOC gains at a rate of 0.09 Mg ha−1 yr−1. Consequently, the removal of crop stover has been demonstrated as a detrimental strategy to store SOC in the short-term in irrigated continuous maize systems.

Irrigation as well as soil tillage management are considered two possible strategies to reduce carbon dioxide (CO2) and methane (CH4) emissions from the soil in Mediterranean agroecosystems. The objective of this work was to assess the impact of the irrigation system (i.e. flood, F; and sprinkler, S) and the soil tillage system (i.e. conventional tillage, CT; no-tillage maintaining the maize stover, NTr; and no-tillage removing the maize stover, NT) on CO2 and CH4 emissions from the soil during three growing seasons (2015, 2016 and 2017) and two fallow periods between growing seasons (15–16 fallow and 16–17 fallow) in a maize (Zea mays L.) monoculture system. Soil temperature and water-filled pore space (WFPS) had a great influence on daily soil CO2 fluxes but not on daily soil CH4 fluxes. In all tillage-irrigation treatments, daily soil CO2 fluxes showed an increase with soil temperature, being this increment greater when soil temperature was above 15 °C in coincidence with the maize plant growth. In contrast, soil WFPS differently affected daily soil CO2 fluxes depending on the irrigation system. Under S irrigation, daily soil CO2 fluxes increased with soil WFPS, whereas under F irrigation a threshold value of 60% WFPS was found, with a positive or negative effect on CO2 fluxes for values below or above this threshold value, respectively. Over the three maize growing seasons, CT-S presented the greatest cumulative soil CO2 emissions with a seasonal average value of 3.28 Mg CO2-C ha−1. In contrast, for the same period, NTr-S cumulative soil CO2 emissions were up to 42% lower than the CT-S cumulative soil CO2 emissions. Cumulative CH4 emissions were only affected by soil tillage during the 16–17 fallow period, resulting both NTr and NT in greater net CH4 uptake compared with CT. This work highlights the importance of irrigation and soil tillage systems as key agricultural practices to minimize soil CO2 and CH4 emissions under Mediterranean conditions.

The work shows, through results from different long-term experiments and some insights on crop rotation performance in commercial farms, how the adoption of conservation tillage, rational use of N fertilizers, sowing date delay and crop diversification, as integrated cropping system approach, can make wheat-based production systems more sustainable under Mediterranean conditions.

• Maize monocropping is the main cropping system under irrigated conditions in Spain. • Typical management includes high N fertilizer rates and irrigation with the concomitant impact on soil greenhouse gas emissions (GHG). • This study evaluates the impact of alternative diversified cropping systems to maize monocropping and varying N fertilization rates on soil GHG emissions.

Irrigation management may influence soil greenhouse gas emissions (GHG). Solid-set sprinkler irrigation systems allow to modify the irrigation time and frequency. The objective of this study was to quantify the effect of two irrigation times (daytime, D; nighttime, N) and two irrigation frequencies (low, L; high, H) on soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions in a solid-set sprinkler-irrigated maize (Zea mays L.) field located in NE Spain during 2015 and 2016 growing seasons and the fallow period between growing seasons. Compared with D irrigation, N irrigation increased soil water content (0–5 cm) in both growing seasons. Irrigation management did not affect CH4 emissions and the soil acted as a sink of CH4. Cumulative CO2 emissions were affected by the measurement period (growing season vs fallow) with the greatest values in 2015 growing season, being 81 and 32% higher over the fallow period and over the 2016 growing season, respectively, due to the effect of the preceding crop, alfalfa, and a better soil moisture conditions for the microorganism activity. Similarly, cumulative N2O emissions showed the highest values in 2015, reporting values 90 and 51% greater than the fallow period and the 2016 growing season, respectively. Moreover, N irrigation increased cumulative N2O emissions by 29% compared with D irrigation, but irrigation frequency did not affect cumulative N2O emissions. Irrigation time did not affect cumulative N2O emissions scaled per grain yield or per N uptake because N irrigation increased maize yield by 11% compared with D irrigation. Due to the lack of differences in the scaled N2O emissions, N irrigation should be consider as an appropriate strategy to optimize grain yield without compromising soil GHG emissions per unit of grain yield in Mediterranean agroecosystems.

En los sistemas de producción de cultivos herbáceos extensivos con siembras otoñales, las operaciones de fertilización representan un importante coste de producción. La eficiencia en el uso de los fertilizantes es fundamental, ya que estudios actuales indican que como media, la eficiencia en el uso de los fertilizantes nitrogenados no alcanza el cincuenta por ciento, incluso es más baja para el fosforo y el potasio. Se muestran tres ejemplos prácticos de fertilización de cultivos de siembra otoñal en distintas condiciones de cultivo.

La superficie que ocupan en Aragón los suelos cerealistas es muy importante, que la productividad del suelo no parece empeorar con el tiempo y, por último, que para mantener y/o mejorar esa productividad debemos mantener y/o mejorar la calidad y salud de dichos suelos. Sin embargo, los estudios edafológicos llevados a cabo durante las últimas décadas en los centros e institutos de investigación de Aragón han puesto de manifiesto la fragilidad de muchos de nuestros suelos cerealistas, por ejemplo, aquellos que en los secanos áridos y semiáridos del centro de Aragón están dedicados al cultivo de “año y vez”. Este sistema de cultivo conlleva largos periodos de barbecho, durante los cuales el suelo, desnudo o desprovisto de una cubierta vegetal adecuada, queda a merced de la acción del viento y del agua, lo que puede suponer, sin duda, importantes pérdidas de suelo y nutrientes.

Índice de la presentación: 1) Definición de edafoteca, función y normas de archivo. 2) Edafotecas vinculadas a experimentos de larga duración. 3) Edafotecas nacionales. 4) Ejemplos de utilización de las muestras de suelo archivadas en una edafoteca. 5) Nuestras edafotecas.

Los resultados que se presentan en este documento corresponden a los 4 primeros años de experimento (campañas 2010-2011, 2011-2012, 2012-2013 y 2013-2014) en los que el sistema de cultivo fue un monocultivo de cebada. El tratamiento LC consistió en el manejo tradicional de la zona con un pase de grada de discos seguido de uno de cultivador antes de la siembra. En el caso de la SD no se realizó ninguna labor de preparación del suelo, aplicándose glifosato a una dosis de 1,5 L ha-1, antes de la siembra.

Índice de la presentación: 1. Ser científico: integridad y conducta responsable. 2. El fraude científico: algunos ejemplos. 3. La manipulación del sistema de revisión por pares. 4. Editoriales y revistas depredadoras. 5. Referencias y enlaces de interés.

During June 1991 more than 30 scientific teams worked in Castilla-La Mancha, Spain, studying the energy and water transfer processes between soil, vegetation and the atmosphere in semi-arid conditions within the co-ordinated European research project EFEDA (European Field Experiment in Desertification-threatened Areas). Measurements were made from the microscale (e.g. measurements on single plants) up to a scale compatible with the grid size of global models. For this purpose three sites were selected 70 km apart and heavily instrumented at a scale in the order of 30 km2. Aircraft missions, satellite data and movable equipment were deployed to provide a bridge to the larger scale. This paper gives a description of the experimental design along with some of the preliminary results of this successful experiment.