Search

Your search keyword '"Cardenas, Laura M."' showing total 133 results
Start Over Author "Cardenas, Laura M." Publication Year Range Last 10 years
133 results on '"Cardenas, Laura M."'

10. Potential unintended consequences of agricultural land use change driven by dietary transitions

Author

Blackwell, Martin S. A., primary, Takahashi, Taro, additional, Cardenas, Laura M., additional, Collins, Adrian L., additional, Enriquez-Hidalgo, Daniel, additional, Griffith, Bruce A., additional, Hunt, John, additional, Lee, Michael R. F., additional, Misselbrook, Tom H., additional, Neal, Andy L., additional, Jordana Rivero, M., additional, Shield, Ian F., additional, Storkey, Jonathan, additional, Wu, Lianhai, additional, and Harris, Paul, additional

Published
2024
Full Text
View/download PDF

20. Dry rainfed conditions are key drivers of the effect of conservation tillage and a nitrification inhibitor on N fate and N2O emissions: A field 15N tracing study

Author

García Gutiérrez, Sandra, Guardia Vázquez, Guillermo, Montoya Novillo, Mónica, Vallejo Garcia, Antonio, Cardenas, Laura M., García Marco, Sonia, García Gutiérrez, Sandra, Guardia Vázquez, Guillermo, Montoya Novillo, Mónica, Vallejo Garcia, Antonio, Cardenas, Laura M., and García Marco, Sonia

Abstract

The sustainability of rainfed crops under semiarid conditions is threatened by low plant nitrogen (N) recovery as well as the potential loss of reactive N to the environment. A field 15N tracing experiment on barley (Hordeum vulgare L.) under rainfed conditions was carried out to study how different tillage management practices and the use of the nitrification inhibitor DMPSA affected the fate of N. The experiment consisted of a factorial combination of tillage (i.e., no tillage, NT, and conventional tillage, T) and fertilizer treatments (unfertilized control and ammonium nitrate, AN, with or without DMPSA). Single-labelled ammonium nitrate (15NH4NO3, 15AN, or NH415NO3, A15N) was applied at top-dressing to microplots at a rate of 80 kg N ha−1. Our results show out that DMPSA modulates the nitrification process from both fertilizer-N and endogenous soil-N (which was the main contributor to plant N uptake and N2O emissions), affecting soil residual N at the end of the cropping period (i.e., higher topsoil retention of 15AN in DMPSA-amended plots). Generally, cumulative N2O emissions from fertilizer were derived from 15AN rather than from A15N, thus confirming the site-specific choice of the source of synthetic N as an effective N2O mitigation strategy. Two months after harvest, a rewetting event produced a remarkable N2O emission peak that drove total cumulative N2O emissions and was also mainly derived from endogenous N. These results suggest that dry seasons could decrease N2O losses after fertilization while causing critical peaks after rewetting, thus potentially limiting the effectiveness of mitigation strategies. The average plant N recovery from the synthetic fertilizer was 22.6%, while the use of DMPSA combined with NT enhanced plant N uptake from endogenous soil-N. This could be a result of the improved crop development and plant N acquisition under NT, consistent with the decrease of soil N retention for A15N in the deeper layer at the end of the experiment

Published
2023

24. The Importance of Sustained Grassland and Environmental Research: A Case Study From North Wyke Research Station, UK, 1982–2017

Author

Blackwell, Martin S.A., primary, Jarvis, Steve C., additional, Wilkins, Roger J., additional, Beaumont, Deborah A., additional, Cardenas, Laura M., additional, Chadwick, David R., additional, Collins, Adrian L., additional, Dungait, Jennifer A.J., additional, Gibb, Malcolm J., additional, Hopkins, Alan, additional, Lee, Michael R.F., additional, Misselbrook, Tom H., additional, Murray, Philip J., additional, and Tallowin, Jerry R.B., additional

Published
2018
Full Text
View/download PDF

28. Effect of Yerba Mate Extract as Feed Additive on Ruminal Fermentation and Methane Emissions in Beef Cattle

Author

Pena-Bermudez, Yuli A., primary, Vincenzi, Rafaela, additional, Meo-Filho, Paulo, additional, Sakamoto, Leandro S., additional, Lobo, Richard, additional, Benetel, Gabriela, additional, Lobo, Annelise, additional, Matos, Carol, additional, Benetel, Vanderlei, additional, Lima, Cesar G., additional, Berndt, Alexandre, additional, Cardenas, Laura M., additional, and Bueno, Ives C. S., additional

Published
2022
Full Text
View/download PDF

30. Effect of Cow Urine Nitrogen Rates and Moisture Conditions on Nitrogen Mineralization in Andisol from Southern Chile.

Author

Ramírez-Sandoval, Magdalena, Pinochet, Dante, Rivero, M. Jordana, and Cardenas, Laura M.

Subjects
VOLCANIC soils, URINE, UREA, COWS, MOISTURE, MINERALIZATION, SOIL drying
Abstract

Urea present in cattle urine contributes large amounts of nitrogen (N) to grazed pastures, which can be the equivalent to approximately 1000 kg N ha−1. However, there are no studies in volcanic soils of southern Chile on the effect of different concentrations of urinary N deposited in the soil, nor of the effect different wetting and drying conditions mimicking the variation in weather conditions on the nitrification process from urea to NH4+ and total oxidized nitrogen (TON) over time. In addition, the inhibition of nitrification driven by the accumulation of NH3 at high rates of N applied to Andisol has not been evaluated. Fresh cattle urine was applied at three different rates of N equivalent to 247 kg N ha−1 (Low N), 461 kg N ha−1 (Medium N), and 921 kg N ha−1 (High N), as well as deionized water as a control. Further, three moisture conditions were imposed: constant moisture (CM), drying–rewetting (DRW) cycles at 7-day intervals, and soil drying (SD). Destructive soil core samples were evaluated for top and bottom halves individually every 7 days over a 36-day period to measure changes on inorganic N and pH. There were no interaction effects for N rates and soil moisture. The main effect of the different rates of N on mineralization was significant throughout the incubation period, while the effect of the different moisture conditions was variable over time. High N was associated with elevated NH3 concentrations and could explain why total N mineralization was partially inhibited. These results suggest that the presence of different nitrifying microorganisms in soil under different chemical and physical conditions determines nitrification, and thus, the oxidation of ammonia should be studied in more detail as the first step of nitrification, specifically in volcanic soils. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

32. Beneficial effects of multi-species mixtures on N2O emissions from intensively managed grassland swards

Author

Cummins, Saoirse, Finn, John A., Richards, Karl G., Lanigan, Gary J., Grange, Guylain, Brophy, Caroline, Cardenas, Laura M., Misselbrook, Tom H., Reynolds, Christopher K., and Krol, Dominika J.

Abstract

In a field experiment, annual nitrous oxide (N2O) emissions and grassland yield were measured across different plant communities, comprising systematically varying combinations of monocultures and mixtures of three functional groups (FG): grasses (Lolium perenne, Phleum pratense), legumes (Trifolium pratense, Trifolium repens) and herbs (Cichorium intybus, Plantago lanceolata). Plots received 150 kg ha−1 year−1 nitrogen (N) (150 N), except L. perenne monocultures which received two N levels: 150 N and 300 N. The effect of plant diversity on N2O emissions was derived from linear combinations of species performances' in monoculture (species identity) and not from strong interactions between species in mixtures. Increasing from 150 N to 300 N in L. perenne resulted in a highly significant increase in cumulative N2O emissions from 1.39 to 3.18 kg N2O-N ha−1 year−1. Higher N2O emissions were also associated with the legume FG. Emissions intensities (yield-scaled N2O emissions) from multi-species mixture communities around the equi-proportional mixture were lowered due to interactions among species. For N2O emissions scaled by nitrogen yield in forage, the 6-species mixture was significantly lower than L. perenne at both 300 N and 150 N. In comparison to 300 N L. perenne, the same N yield or DM yield could have been produced with the equi-proportional 6-species mixture (150 N) while reducing N2O losses by 63% and 58% respectively. Compared to 150 N L. perenne, the same N yield or DM yield could have been produced with the 6-species mixture while reducing N2O losses by 41% and 24% respectively. Overall, this study found that multi-species grasslands can potentially reduce both N2O emissions and emissions intensities, contributing to the sustainability of grassland production.

Published
2021

35. Mechanisms of nitrogen transfer in a model clover-ryegrass pasture: a 15N-tracer approach.

Author

Reay, Michaela K., Pears, Katrina A., Kuhl, Alison, Evershed, Richard P., Murray, Phillip J., Cardenas, Laura M., Dungait, Jennifer A. J., and Bull, Ian D.

Subjects
RYEGRASSES, WHITE clover, LOLIUM perenne, PASTURES, SOIL microbiology, LAND management
Abstract

Purpose : Nitrogen (N) transfer from white clover (Trifolium repens cv.) to ryegrass (Lolium perenne cv.) has the potential to meet ryegrass N requirements. This study aimed to quantify N transfer in a mixed pasture and investigate the influence of the microbial community and land management on N transfer. Methods: Split root 15N-labelling of clover quantified N transfer to ryegrass via exudation, microbial assimilation, decomposition, defoliation and soil biota. Incorporation into the microbial protein pool was determined using compound-specific 15N-stable isotope probing approaches. Results: N transfer to ryegrass and soil microbial protein in the model system was relatively small, with one-third arising from root exudation. N transfer to ryegrass increased with no microbial competition but soil microbes also increased N transfer via shoot decomposition. Addition of mycorrhizal fungi did not alter N transfer, due to the source-sink nature of this pathway, whilst weevil grazing on roots decreased microbial N transfer. N transfer was bidirectional, and comparable on a short-term scale. Conclusions: N transfer was low in a model young pasture established from soil from a permanent grassland with long-term N fertilisation. Root exudation and decomposition were major N transfer pathways. N transfer was influenced by soil biota (weevils, mycorrhizae) and land management (e.g. grazing). Previous land management and the role of the microbial community in N transfer must be considered when determining the potential for N transfer to ryegrass. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

39. Nitrous oxide emissions from ruminant urine: Science and mitigation for intensively managed perennial pastures

Author

Clough, Timothy J., Cardenas, Laura M., Friedl, Johannes, Wolf, Benjamin, Clough, Timothy J., Cardenas, Laura M., Friedl, Johannes, and Wolf, Benjamin

Abstract

Despite optimising fertiliser practice and nitrogen (N) use efficiency nitrous oxide N2O generation from ruminant-urine deposition prevails due to the concentration of N in the urine excreted. Development and application of mitigation strategies to reduce N2O emissions from grazed pasture systems requires knowledge of production and consumption pathways, and factors affecting these. Soil physical properties regulate the soil aeration status (redox potential) selecting for microbial pathways processing inorganic-N. Mitigation of N2O emissions must initially target the prevention of NO and NO2− during nitrification by inhibiting ammonia oxidation, but must also consider what microbes are being targeted. Biological nitrification inhibition as a potential mitigation option in pasture systems remains under researched. Emerging research demonstrates that previously unrecognised effects of soil organic matter content, soil fertility (phosphorus levels) and non-linear effects of soil temperature on nitrification require a better understanding in relation to N2O emissions and their mitigation.

Published
2020

43. Towards Country-Specific Nitrous Oxide Emission Factors for Manures Applied to Arable and Grassland Soils in the UK

Author

Thorman, Rachel E., primary, Nicholson, Fiona A., additional, Topp, Cairistiona F. E., additional, Bell, Madeleine J., additional, Cardenas, Laura M., additional, Chadwick, David R., additional, Cloy, Joanna M., additional, Misselbrook, Tom H., additional, Rees, Robert M., additional, Watson, Catherine J., additional, and Williams, John R., additional

Published
2020
Full Text
View/download PDF

46. Evaluación de los procesos de siembra y corte de flores mediante simulación de eventos discretos.

Author

Osorio Gutierrez, Carmenza, Ortiz García, Ronald Akerman, and Cardenas, Laura M.

Abstract

Copyright of Prospectiva (1692-8261) is the property of Universidad Autonoma del Caribe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2021
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results