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20. Zinc-nitrogen co-fertilization influences N2O emissions and microbial communities in an irrigated maize field

Author

European Commission, Comunidad de Madrid, Ministerio de Economía y Competitividad (España), Campus de Excelencia Internacional Moncloa, Montoya, Mónica, Guardia, Guillermo, Recio, Jaime, Castellano-Hinojosa, Antonio, Ginés, C., Bedmar, Eulogio J., Álvarez, José Manuel, Vallejo, Antonio, European Commission, Comunidad de Madrid, Ministerio de Economía y Competitividad (España), Campus de Excelencia Internacional Moncloa, Montoya, Mónica, Guardia, Guillermo, Recio, Jaime, Castellano-Hinojosa, Antonio, Ginés, C., Bedmar, Eulogio J., Álvarez, José Manuel, and Vallejo, Antonio

Abstract

Previous studies have shown that the use of zinc (Zn) chelate fertilizers combined with a nitrogen (N) fertilizer (urea) can lead to both agronomic (i.e., yields and Zn and N biofortification due to the synergies between both nutrients) and environmental (i.e., by reducing the emissions of nitrous oxide, NO, derived from N fertilization) benefits under rainfed semi-arid conditions. However, little is known about the effect of Zn-N co-fertilization on greenhouse gas (GHG) emissions or soil microbial processes involved in NO fluxes under non-flooded irrigated conditions (during the dry season). Under these conditions, water-filled pore space continuously fluctuates following a periodic pattern and soil temperatures are in the optimum range for soil microorganisms. In this context, a field experiment was conducted using a maize (Zea mays L.) crop treated with two N levels (no N application and 120 kg N ha as urea), and three Zn sources (no Zn application, Zn sulphate, and Zn applied with a mixture of chelating compounds, DTPA-HEDTA-EDTA). Nitrous oxide, methane (CH) and carbon dioxide (CO) fluxes were measured using opaque chambers, as well as the total abundances of soil bacteria, archaea and nitrifier and denitrifier communities. Zn-N co-fertilization increased cumulative NO emissions from 0.36 kg N-NO ha (for urea combined with Zn chelates) to 0.76 kg N-NO ha (for urea combined with Zn sulphate), with respect to urea without Zn application. The NO emission factors were lower (0.34%–0.72%) than the IPCC default value of 1%. Total abundances of the nosZ denitrification gene, which is involved in the reduction in NO to dinitrogen (N), were reduced by 75% on average in the plots that received Zn fertilizers. This reduction may explain the higher NO emissions in these treatments. In contrast with the case with non-irrigated crops, Zn-N co-fertilization cannot be recommended as a strategy to mitigate NO emissions in irrigated maize under semi-arid conditions, despite of t

Published
2021

22. Carcinoma espinocelular: reporte de caso en paciente con fototipo tipo 5 según clasificación Fitzpatrick

Author

Bonivento Johnsson, Petty, Trout Guardia, Guillermo, Maestre Garzon, Jamith, Muñoz Vergara, Mayra, and Moreno Ochoa, Maria Carolina

Abstract

Spinocellular carcinoma is a subtype of neoplasia that does not involve melanocytes, and together with basal cell carcinoma, they represent 75% of non-melanoma skin carcinomas. In Colombia, it was calculated that from 2003 to 2007 non-melanoma cancer registered an uptick of 19 to 39 cases per 100,000 inhabitants. Spinocellular carcinoma tends to appear in skin phototypes 1 and 2, in photoexposed areas that represent head and neck (70%), in upper extremities (25%) and in non-photoexposed areas such as buttocks and genital mucous membranes (5%). This article makes a case report of a spinocellular carcinoma in a 51-year-old patient with a clinical picture of approximately two years that was characterized by various tumors located in the right lower lip and lower jaw related to chronic sun exposure and presence of actinic keratosis on face and scalp. El carcinoma espinocelular es un subtipo de neoplasia que no involucra a los melanocitos, y junto con el carcinoma basocelular, representan el 75% de los carcinomas de piel no melanoma. En Colombia, se calculó que de 2003 a 2007 el cáncer no melanoma registró un incremento de 19 a 39 casos por 100 000 habitantes. El carcinoma espinocelular tiende a aparecer en fototipos de piel 1 y 2, en áreas fotoexpuestas que representan cabeza y cuello (70%), en extremidades superiores (25%) y en zonas no fotoexpuetas como glúteos y mucosas genitales (5%). Este artículo hace un reporte de caso de un carcinoma espinocelular en un paciente de 51 años con un cuadro clínico aproximadamente de dos años que se caracterizó por diversos tumores localizados en labio inferior derecho y maxilar inferior y que estuvo relacionado a exposición solar crónica y presencia de queratosis actínica en cara y cuero cabelludo. O carcinoma espinocelular é um subtipo de neoplasia que não envolve os melanócitos, e junto com o carcinoma basocelular, representam 75% dos carcinomas de pele não melanoma. Na Colômbia, calculou-se que de 2003 a 2007 o câncer não melanoma registrou um aumento de 19 a 39 casos por 100 000 habitantes. O carcinoma espinocelular tende a aparecer em fototipos de pele I e II, em áreas fotoexpostas que representam cabeça e pescoço (70%), em extremidades superiores (25%) e em áreas não fotoexpostas como glúteos e mucosas genitais (5%). Este artigo faz um relato de caso de um carcinoma espinocelular num paciente de 51 anos com um quadro clínico aproximadamente de dois anos que se caracterizou por diversos tumores localizados em lábio inferior direito e maxilar inferior e que esteve relacionado à exposição solar crônica e presença de ceratose actínica na cara e no couro cabeludo.

Published
2019

26. Zinc fertilizers influence greenhouse gas emissions and nitrifying and denitrifying communities in a non-irrigated arable cropland

Author

Ministerio de Economía y Competitividad (España), European Commission, Montoya, Mónica, Castellano-Hinojosa, Antonio, Vallejo, Antonio, Álvarez, José Manuel, Recio, Jaime, Guardia, Guillermo, Bedmar, Eulogio J., Ministerio de Economía y Competitividad (España), European Commission, Montoya, Mónica, Castellano-Hinojosa, Antonio, Vallejo, Antonio, Álvarez, José Manuel, Recio, Jaime, Guardia, Guillermo, and Bedmar, Eulogio J.

Abstract

Fertilization with micronutrients (e.g., zinc, Zn) is essential in order to overcome the global nutritional problems associated with human micronutrient deficiencies. However, little is known about the effect of micronutrient fertilizers and their interaction with nitrogen (N) on greenhouse gas (GHG) emissions and soil microbial processes involved in nitrous oxide (NO) fluxes. In this context, a one-year field experiment was carried out using a winter wheat (Triticum aestivum L.) crop in Central Spain. Winter wheat was treated with different Zn sources (Zn-sulphate, Zn-lignosulphonate, Zn with a mixture of synthetic chelating compounds DTPA-HEDTA-EDTA and Zn-humic/fulvic acids) and N rates (0, 120 and 180 kg N ha). Zn sources were applied at 10 kg Zn ha for Zn-sulphate and 0.36 kg Zn ha for the rest of treatments. Nitrous oxide, methane (CH) and respiration fluxes were measured (two-three times per week during the first month after each fertilization and thereafter with decreasing frequency), as were the total abundances of soil Bacteria and Archaea, ammonia-oxidizing Bacteria and Archaea, and denitrifying bacteria. The DTPA-HEDTA-EDTA reduced cumulative NO losses by 21.4% and respiration fluxes by 24.4% from those of the no Zn application. The chelating of metal co-factors (mainly copper, Cu) of the enzymes involved in the nitrification and denitrification steps was the probable mechanism for the reduction of NO emissions as bacterial amoA, nirK, nirS and norB gene abundances, as well as the extractable Cu content, decreased in this treatment. Unexpectedly, the DTPA-HEDTA-EDTA increased the copy number of nosZ by 31.2% over that of the no Zn application. The Zn applied together with the humic/fulvic acids mixture caused significant increases of total bacterial abundance and nitrifier and denitrifier communities, particularly the norB gene, thereby leading to the highest NO emissions. The optimum N rate was 120 kg N ha since it resulted in the lowest yield-scaled NO

Published
2018

27. The scarcity and distribution of rainfall drove the performance (i.e., mitigation of N oxide emissions, crop yield and quality) of calcium ammonium nitrate management in a wheat crop under rainfed semiarid conditions.

Author

Guardia, Guillermo, González-Murua, Carmen, Fuertes-Mendizábal, Teresa, and Vallejo, Antonio

Subjects
*CROP quality, *AMMONIUM nitrate, *CROP management, *CROP yields, *CALCIUM nitrate, *WHEAT yields, *DRY farming
Abstract

Selection and management of synthetic nitrogen (N) fertilizers, including nitrification inhibitors, are considered an effective strategy to mitigate N oxide emissions, but depends strongly on soil characteristics and climatic conditions. We evaluated the effect of the use of a nitrification inhibitor (2-(3,4-dimethyl-1H-pyrazol-1-yl) succinic acid isomeric mixture (DMPSA)) or splitting calcium ammonium nitrate (CAN) on the N oxides and CH4 emissions, yield, N use efficiency (NUE) and bread-making quality in a winter wheat (Triticum aestivum L.) crop. During a typical rainfall cropping season, neither splitting CAN nor using DMPSA reduced significantly the area-scaled or yield-scaled emissions in comparison to a single application of CAN without inhibitors. This could be explained by the low emissions in CAN amended plots. Conversely, in the subsequent extremely dry cropping season, higher N oxide peaks occurred after soil rewetting and the effectiveness of DMPSA was significant in these conditions (e.g. 83% mitigation for NO). No improvement in the NUE, yield or bread-making quality was achieved with a split application or DMPSA added to the fertilizer. Under the conditions of the study, splitting CAN should not be recommended from a yield-scaled emissions viewpoint, while the use of DMPSA may be encouraged due to large variability in the amount and distribution of rainfall. [ABSTRACT FROM AUTHOR]

Published
2020
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34. Effect of organic and mineral fertilizers on greenhouse gases emissions from an irrigated maize crop in Madrid Spain

Author

Guardia, Guillermo, Sanz Cobeña, Alberto, Cangani, Max T., Andreu, Gemma, Téllez Del Río, Ángela, Garcia Marco, Sonia, and Vallejo Garcia, Antonio

Subjects
Agricultura, fungi, food and beverages
Abstract

Both solid or liquid OF showed a significant abatement of N2O cumulative emissions in this irrigated Mediterranean cropping area (P < 0.05) comparing to U. Urea-Pig Compost (U-PC) treatment showed the lowest CH4 sink and highest cumulative soil respiration rates (P

Published
2014

37. Crop rotation and residues influence N2O emission and N efficiency rather than tillage under a rainfed Mediterranean agroecosystem

Author

Guardia, Guillermo, Téllez del Río, Ángela, Garcia Marco, Sonia, Tenorio, J. L., and Vallejo Garcia, Antonio

Subjects
Agricultura, food and beverages, equipment and supplies
Abstract

Conservation tillage and crop rotation have spread during the last decades because promotes several positive effects (increase of soil organic content, reduction of soil erosion, and enhancement of carbon sequestration) (Six et al., 2004). However, these benefits could be partly counterbalanced by negative effects on the release of nitrous oxide (N2O) (Linn and Doran, 1984). There is a lack of data on long-term tillage system study, particularly in Mediterranean agro-ecosystems. The aim of this study was to evaluate the effects of long-term (>17 year) tillage systems (no tillage (NT), minimum tillage (MT) and conventional tillage (CT)); and crop rotation (wheat (W)-vetch (V)-barley (B)) versus wheat monoculture (M) on N2O emissions. Additionally, Yield-scaled N2O emissions (YSNE) and N uptake efficiency (NUpE) were assessed for each treatment.

Published
2014

38. Evaluación de prácticas agrícolas (laboreo y rotación) para mitigar gases de efecto invernadero en clima mediterráneo

Author

Guardia, Guillermo, Téllez del Río, Ángela, Garcia Marco, Sonia, Tenorio, J. L., and Vallejo Garcia, Antonio

Subjects
Agricultura
Abstract

El laboreo de conservación (Mínimo Laboreo, ML; No Laboreo, NL) y la rotación de cultivos están consideradas como Buenas Prácticas Agrícolas, y contribuyen a mejorar las propiedades físicas y la fertilidad del suelo, así como a reducir el empleo de algunos insumos agrarios (Follet y Schimel 1989). Sin embargo, existe gran controversia sobre el efecto de estas prácticas sobre las emisiones de Gases de Efecto Invernadero (GEI), a las que la agricultura contribuye en un 13.5 %, siendo normalmente el óxido nitroso (N2O) el mayor determinante del Poder de Calentamiento Global derivado de los agrosistemas (IPCC, 2006). La variabilidad de resultados y la escasez de estudios en zonas mediterráneas, especialmente sobre el efecto de la rotación de cultivos, justifican la necesidad de nuevos estudios sobre este tema. El objetivo principal de este ensayo ha sido evaluar la influencia de las prácticas de laboreo de conservación frente al Laboreo Tradicional (LT) mediante vertedera; así como la rotación barbecho - trigo (Tritucum aestivum L. var. ́Marius`) frente a monocultivo de trigo, sobre las emisiones de GEI(N2O, CH4 y CO2) desde el suelo.

Published
2014

42. Fate of 15N-labelled ammonium nitrate with or without the new nitrification inhibitor DMPSA in an irrigated maize crop.

Author

Guardia, Guillermo, Vallejo, Antonio, García-Marco, Sonia, Cardenas, Laura M., and Dixon, Elizabeth R.

Subjects
*CORN, *AMMONIUM nitrate, *SOIL leaching, *LEACHING, *NITRIFICATION inhibitors, *NITRIFICATION, *PREVENTION
Abstract

Nitrification inhibitors, originally proposed for nitrate leaching mitigation, are recommended as effective nitrous oxide (N 2 O) mitigation strategies. Several compounds have been trialled and used in the past including dicyandiamide (DCD) or 3,4-dimethylpyrazole phosphate (DMPP). Yet, little is known about the new nitrification inhibitor 2-(3,4-dimethyl-1H-pyrazol-1-yl) succinic acid isomeric mixture (DMPSA). A field experiment using 15 N single-labelled ammonium nitrate ( 15 NH 4 NO 3 or NH 4 15 NO 3 ) was conducted to understand the effectiveness of DMPSA on a biochemical basis in an irrigated maize ( Zea mays L.) crop. Gaseous fluxes, i.e. N 2 O, 15 N 2 O, 15 N 2 , methane (CH 4 ), and carbon dioxide (CO 2 ) were measured, as well as soil mineral N, yield components and 15 N recovery in plant and soil. During the maize cropping period, the use of DMPSA significantly reduced cumulative N 2 O emissions (118 g N ha −1 ) compared to ammonium nitrate without inhibitor (231 g N ha −1 ). The 15 N analyses revealed that most N 2 O losses (particularly during the emission peak) came from 15 NH 4 NO 3 (i.e. nitrification, nitrifier denitrification and/or coupled nitrification denitrification) rather than NH 4 15 NO 3 in this calcareous low C-content soil. As expected, DMPSA decreased N 2 O losses from 15 NH 4 + oxidation, but an effect on non-target microorganisms was noticed, as shown by the significant reduction of respiration rates and N 2 O losses coming from 15 NO 3 − . No significant effect of DMPSA on CH 4 oxidation or 15 N 2 fluxes was observed. The DMPSA did not lead to a significant improvement of the dry weights of grain or biomass, although an increment of root biomass by 64% was found. This compound also tended to increase plant N recovery (average 67.8%) and to decrease soil N recovery (average 18.3%) but differences were not statistically significant. Conversely, the nitrification inhibitor significantly reduced the residual fertilizer-N in the 15–30 cm and 30–45 cm soil layers. The use of DMPSA was confirmed as a highly effective tool to reduce N 2 O emissions from irrigated crops in semi-arid areas. [ABSTRACT FROM AUTHOR]

Published
2018
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43. Yield-scaled mitigation of ammonia emission from N fertilization: the Spanish case

Author

Universitat Politècnica de València. Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural - Escola Tècnica Superior d'Enginyeria Agronòmica i del Medi Natural, Gobierno de la Comunidad de Madrid, Social Sciences and Humanities Research Council of Canada, Ministerio de Ciencia e Innovación, Sanz-Cobeña, A., Lassaletta, L., Estellés, F., Del Prado, A., Guardia Guardia, Guillermo, Abalos, Diego, Aguilera, Eduardo, Pardo, G., Vallejo, A., Sutton, M.A., Garnier, J., Billen, G., Universitat Politècnica de València. Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural - Escola Tècnica Superior d'Enginyeria Agronòmica i del Medi Natural, Gobierno de la Comunidad de Madrid, Social Sciences and Humanities Research Council of Canada, Ministerio de Ciencia e Innovación, Sanz-Cobeña, A., Lassaletta, L., Estellés, F., Del Prado, A., Guardia Guardia, Guillermo, Abalos, Diego, Aguilera, Eduardo, Pardo, G., Vallejo, A., Sutton, M.A., Garnier, J., and Billen, G.

Abstract

Online supplementary data available from stacks.iop.org/ERL/9/125005/mmedia, [EN] Synthetic nitrogen (N) fertilizer and field application of livestock manure are the major sources of ammonia (NH3) volatilization. This N loss may decrease crop productivity and subsequent deposition promotes environmental problems associated with soil acidification and eutrophication. Mitigation measures may have associated side effects such as decreased crop productivity (e.g. if N fertilizer application is reduced), or the release of other reactive N compounds (e.g. N2O emissions if manure is incorporated). Here, we present a novel methodology to provide an integrated assessment of the best strategies to abate NH3 from N applications to crops. Using scenario analyses, we assessed the potential of 11 mitigation measures to reduce NH3 volatilization while accounting for their side effects on crop productivity, N use efficiency (NUE) and N surplus (used as an indicator of potential N losses by denitrification/nitrification and NO3 − leaching/run-off). Spain, including its 48 provinces, was selected as a case study as it is the third major producer of agricultural goods in Europe, and also the European country with the highest increase in NH3 emissions from 1990 to 2011. Mitigation scenarios comprised of individual measures and combinations of strategies were evaluated at a country- and regional level. Compared to the reference situation of standard practices for the year 2008, implementation of the most effective region-specific mitigation strategy led to 63% NH3 mitigation at the country level. Implementation of a single strategy for all regions reduced NH3 by 57% at the highest. Strategies that involved combining mitigation measures produced the largest NH3 abatement in all cases, with an 80% reduction in some regions. Among the strategies analyzed, only suppression of urea application combined with manure incorporation and incorporation of N synthetic fertilizers other than urea showed a fully beneficial situation: yieldscaled NH3 emissions were reduced by 8

Published
2014

44. Uso de malla reabsorbible en traumatismo esplénico en ratas

Author

Sánchez, Dina, Mendoza, Manuel, Guardia, Guillermo, Sánchez, David, Pereyra, Sonia, and Vega, Elena

Subjects
traumatismos abdominales, Ácido poliglicólico, abdominal injuries, glicolatos, esplenectomía, Polyglycolic acid, glycolatos, splenectomy
Abstract

Objective: To determine if use of reabsorbing mesh stops hemorrhage and avoids spleen removal in abdominal trauma. Design: Experimental study. Setting: Experimental Surgery Service, of both UNMSM and Children’s Hospital. Materials: Reabsorbing mesh (polyglycolic acid), rats, anesthesia, minor surgery equipment, materials for anatomical tissues. Interventions: Under general anesthesia rats were opened by midline incision to expose the spleen, which was injured in 1st, 2nd and 3rd degrees, then covered with reabsorbing mesh, fixing with catgut 3/0 and pressing until bleeding was restrained; then abdominal cavity was closed with vicryl 3/0. Clinical evaluation was done at 24, 48 and 72 hours post-surgery to observe survival, then re-opened randomly at 15, 30 days and 3 months to see the presence of adhesions and mesh reabsorption. Main outcome measures: Survival, adhesions, mesh reabsorption. Results: From the 60 rats with 1st, 2nd, and 3rd degree lesions 97% survived (58 rats) and 3% died (2 rats: one rat with 1º degree injury died at 24 hours because of aggression from another rat and another rat with 3º degree injury died 72 hours post op and at necropsy showed micro abscesses in mesentery and liver). At 15 and 30 days we observed intra-abdominal adhesions, and at 3 months total reabsorption of the mesh. Conclusions: Reabsorbing mesh (polyglycolic acid) is a material that restrains bleeding and avoids spleen extraction in abdominal trauma bleeding. Objetivo: Determinar si el empleo de malla reabsorbible cohibe la hemorragia y evita la exéresis del bazo en el traumatismo abdominal. Diseño: Estudio experimental. Lugar: Servicio de Técnica Quirúrgica y Cirugía Experimental, Universidad Nacional Mayor de San Marcos, y Servicio de Cirugía Experimental, Hospital del Niño, Lima, Perú. Materiales: Malla reabsorbible (ácido poliglicólico), ratas, anestésicos, instrumentos de cirugía menor, material para fijación anatomopatológico. Intervenciones: Bajo anestesia general, se laparotomizó a la rata con incisión mediana, para exponer el bazo, al cual se produjo lesiones de 1º, 2º y 3º grados; luego, se cubrió con la malla reabsorbible, fijando alrededor con catgut 3/0, presionando hasta cohibir la hemorragia; enseguida se cerró cavidad abdominal con puntos de vicryl 3/0. Se evaluó clínicamente a las 24, 48 y 72 horas posquirúrgicas, para observar la supervivencia; luego, relaparotomía al azar, a los 15 y 30 días y 3 meses, para ver presencia de adherencias y tiempo de reabsorción de la malla. Principales medidas de resultados: Supervivencia, adherencias posquirúrgicas y reabsorción de la malla. Resultados: De las 60 ratas con lesiones de 1º, 2º y 3º grados, se observó una supervivencia de 97% (58 ratas) y 3% murieron (2 ratas: una rata con lesión de 1º grado a las 24 horas por agresión y otra con lesión de 3º grado a las 72 horas que a la necropsia se encontró microabscesos en omento e hígado). A los 15 y 30 días de relaparotomía, se observó presencia de adherencias intraabdominales y, a los 3 meses, reabsorción total de la malla. Conclusiones: La malla reabsorbible (ácido poliglicólico) es un material que, aparte de cohibir la hemorragia, evita la esplenectomía, conservando el bazo en casos de hemorragia por traumatismo abdominal.

Published
2007

46. Fertilización y N2O. Implicaciones en la huella de carbono.

Author

Vallejo Garcia, Antonio, Ábalos Rodríguez, Diego, Téllez del Río, Ángela, Guardia, Guillermo, Vallejo Garcia, Antonio, Ábalos Rodríguez, Diego, Téllez del Río, Ángela, and Guardia, Guillermo

Abstract

Todos los alimentos obtenidos de origen vegetal llevan asociada una cierta cantidad de emisiones de Gases de Efecto Invernadero (GEI), que se cuantifican a través de su huella de carbono. De los GEI, la agricultura es principalmente responsable de la emisión de óxido nitroso (N2O), que es el que presenta mayor poder de calentamiento global. La metodología del IPCC, aparte de sobreestimar con su valor por defecto las emisiones de N2O de nuestros agrosistemas, no tiene en cuenta el fin último de la agricultura que es satisfacer la demanda mundial de alimentos, fibras y combustibles. Por ello, en este artículo se propone evaluar las emisiones de N2O en base al rendimiento del cultivo. Posteriormente, se enumeran una serie de buenas prácticas agrícolas cuyo fin es aumentar la eficiencia del uso del N por parte del cultivo así como reducir las emisiones de N2O.

Published
2013

48. Integrated soil fertility management drives the effect of cover crops on GHG emissions in an irrigated field.

Author

Guardia, Guillermo, Abalos, Diego, García-Marco, Sonia, Quemada, Miguel, Alonso-Ayuso, María, Cárdenas, Laura M., Dixon, Elizabeth R., and Vallejo, Antonio

Subjects
SOIL fertility management, EFFECT of greenhouse gases on plants, COVER crops, IRRIGATION, INTERCROPPING, AGRONOMY
Abstract

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. The ISFM resulted in low cumulative N2O emissions (0.57 to 0.75 kg N2O-N ha-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. [ABSTRACT FROM AUTHOR]

Published
2016
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