A5041791185- Soil Carbon and Nitrogen Dynamics
- Soil and Water Nutrient Dynamics
- Agriculture Sustainability and Environmental Impact
- Agronomic Practices and Intercropping Systems
- Agricultural Economics and Policy
- Soil and Unsaturated Flow
- Climate change impacts on agriculture
- Hydrology and Watershed Management Studies
- Microbial Community Ecology and Physiology
- Cassava research and cyanide
- Soil Geostatistics and Mapping
- Agroforestry and silvopastoral systems
- Rangeland Management and Livestock Ecology
- Mycorrhizal Fungi and Plant Interactions
- Crop Yield and Soil Fertility
- Ruminant Nutrition and Digestive Physiology
- Groundwater and Isotope Geochemistry
- Environmental Impact and Sustainability
- Peatlands and Wetlands Ecology
- Agricultural economics and policies
- Plant responses to elevated CO2
- Aeolian processes and effects
- Turfgrass Adaptation and Management
- Pasture and Agricultural Systems
- Land Use and Ecosystem Services
University College Dublin
2020-2024
ETH Zurich
2015-2024
University of Wisconsin–Madison
2014-2015
Teagasc - The Irish Agriculture and Food Development Authority
2010-2013
Waterford Institute of Technology
2010-2013
The ability of biogeochemical ecosystem models to represent agro-ecosystems depends on their correct integration with field observations. We report simultaneous calibration 67 DayCent model parameters using multiple observation types through inverse modeling the PEST parameter estimation software. Parameter reduced total sum weighted squared residuals by 56% and improved fit crop productivity, soil carbon, volumetric water content, temperature, N2O, NO3− compared default simulation. Inverse...
Reduction of soil tillage is paramount importance for agricultural preservation. However, it often accompanied by yield reduction and weed management problems. In this perspective, cover crops could play an important role to alleviate infestation sustain yield. study, the results from a three-year experiment crop cultivation in different treatments presented, together with DayCent simulations on long term evolution organic carbon total nitrogen. Eight were set up as subtreatments...
Abstract. Further progress in understanding and mitigating N2O emissions from soil lies within transdisciplinary research that reaches across spatial scales takes an ambitious look into the future.
Abstract. In sub-Saharan Africa, maize is one of the most important staple crops, but long-term cropping with low external inputs has been associated loss soil fertility. While adding high-quality organic resources combined mineral fertilizer proposed to counteract this fertility loss, effectiveness and interactions site properties still require more understanding. This study used repeated measurements over time assess effect different quantities qualities resource addition nitrogen (N) on...
Abstract This study investigated changes in soil organic carbon ( SOC ) a poorly drained clay loam under (i) permanent grassland PG over 7 years and (ii) after renovation 2·5 years. The experimental area was divided into four blocks with paddocks per block. Composite samples from each block were taken to 30‐cm depth on five occasions between 2004 2011. In June 2008, one paddock renovated by ploughing reseeding sampled as above the latter occasions. Renovation decreased P < 0·05) 32·2 t ha...
Variability in soil organic carbon (SOC) results from natural and human processes interacting across time space, leads to large variation the minimum difference SOC that can be detected with a particular experimental design. Here we report unique comparison of detectable differences (MDDs) SOC, estimated times required observe those MDDs north central United States, calculated for two most common experiments: (1) between treatments, e.g., moldboard plow (MP) no-tillage (NT), using randomized...
The agricultural sector is responsible for substantial amounts of greenhouse gas emissions that exacerbate climate change. Such from upland crops are difficult to abate because they dominated by nitrous oxide (N2O) production soil processes. Strategies reduce these focus on N fertilizer management, and there a widespread assumption legume crops, which do not receive fertilizer, emit little N2O. Here we show this incorrect; approximately 40% N2O the most extensive cropping system in North...
Agricultural systems are a major source of greenhouse gas emissions, contributing significantly to global climate change. As the demand for food increases, there is need identify sustainable soil management practices that minimize environmental impacts while maintaining or enhancing crop productivity. The Daycent model useful tool simulating ecosystem responses changes in and In this study, we calibrated using yield carbon data collected from five long-term ongoing experiments (PROspective...
Measurement of changes in soil organic carbon (SOC) under various management practices at the field scale poses significant challenges due to inherent spatial and temporal variability. &#160;In comparison ecosystem biogeochemical models offer a robust framework for simulating nutrient cycling, SOC, greenhouse gas emissions that can be used identify evaluate long-term effects strengths climate change mitigation strategies. DayCent is coupled soil-plant dynamic model has been widely...
Soil heterotrophic respiration is the process by which carbon stored in soil released into atmosphere as CO&#8322; through microbial breakdown of organic matter. This influences balance between storage and release, impacting levels. Factors such temperature, moisture, availability material determine emissions. Tillage practices alter this changing structure, on airflow, activity, influence decomposition rates fluxes. Understanding these interactions critical for sustainable farming...
The frequency and intensity of extreme weather years, characterized by abnormal precipitation temperature, are increasing. In isolation, these years have disproportionately large effects on environmental N losses. However, the sequence (e.g., wet-dry vs. dry-wet) may affect cumulative We calibrated validated DAYCENT ecosystem process model with a comprehensive set biogeophysical measurements from corn-soybean rotation managed at three fertilizer inputs without winter cover crop in Iowa, USA....
Efficient utilization of incident solar radiation and rainwater conservation in rain-fed smallholder cropping systems require the development adoption with high resource use efficiency. Due to popularity cassava-maize intercropping food security economic importance both crops Nigeria, we investigated options improve interception photosynthetically active (IPAR), efficiency (RUE), soil moisture retention, yields cassava maize 8 on-farm researcher-managed multi-location trials between 2017...
Crop productivity in sub-Saharan Africa cannot be substantially improved without simultaneously addressing short-term crop nutrient demand and long-term soil fertility. Integrated fertility management tackles both by the combined application of mineral fertilizers organic resource inputs but few studies examined its' effectiveness. To address this knowledge gap, study analysed maize yield trends four (31–37 cropping seasons) field experiments Kenya with contrasting textures under different...
Under the United Nations Framework Convention on Climate Change (UNFCCC), industrialized countries and with economies in transition (so called Annex 1 countries) are encouraged to move towards more sophisticated approaches for national greenhouse gas reporting. To develop a model-based approach estimating nitrous oxide (N2O) emissions from agricultural soils, model calibration is one of first important steps. Extensive multisite field observations necessary this purpose, as management...
Cassava is growing in importance Nigeria as a food and industrial crop. Current yields are low due to poor soil fertility because farmers do not use improved germplasm, clean planting material, or crop management Nigeria. To provide feasible agronomic recommendations targeting increased root yield, the effects of tillage intensity, fertilizer application, plant density weed control were tested 230 farmers' fields southwestern over two years. In 2016, treatments zero, single double passage...
Abstract White clover can reduce fertilizer‐N requirements, improve sward nutritive value and increase environmental sustainability of grazed grasslands. Results previous experiments in glasshouse conditions on mown plots have suggested that white may be more susceptible than perennial ryegrass to treading damage wet soils. However, this phenomenon has not been investigated under actual grazing conditions. This experiment examined the effects content, herbage production soil properties...
Cassava-maize intercropping is a common practice among smallholder farmers in Southern Nigeria. It provides food security and early access to income from the maize component. However, yields of both crops are commonly low farmers' fields. Multi-locational trials were conducted Nigeria 2016 2017 investigate options increase productivity profitability through increased cassava plant densities fertilizer application. Trials with 4 6 treatments 2017, respectively established on 126 fields over...
Abstract. Sustainable intensification schemes such as integrated soil fertility management (ISFM) are a proposed strategy to close yield gaps, increase fertility, and achieve food security in sub-Saharan Africa. Biogeochemical models DayCent can assess their potential at larger scales, but these need be calibrated new environments rigorously tested for accuracy. Here, we present Bayesian calibration of DayCent, using data from four long-term field experiments Kenya leave-one-site-out...