Track topics on Twitter Track topics that are important to you
Accurate estimations of ammonia (NH) emissions due to nitrogen (N) fertilization are required to identify efficient mitigation techniques and improve agricultural practices. Process-based models such as Volt'Air can be used for this purpose because they incorporate the effects of several key factors influencing NH volatilization at fine spatio-temporal resolutions. However, these models require a large number of input variables and their implementation on a large scale requires long computation times that may restrict their use by public environmental agencies. In this study, we assess the capabilities of various types of meta-models to emulate the complex process-based Volt'Air for estimating NH emission rates from N fertilizer and manure applications. Meta-models were developed for three types of fertilizer (N solution, cattle farmyard manure, and pig slurry) for four major agricultural French regions (Bretagne, Champagne-Ardenne, Ile-de-France, and Rhône-Alpes) and at the national (France) scale. The meta-models were developed from 106,092 NH emissions simulated by Volt'Air in France. Their performances were evaluated by cross-validation, and the meta-models providing the best approximation of the original model were selected. The results showed that random forest and ordinary linear regression models were more accurate than generalized additive models, partial least squares regressions, and least absolute shrinkage and selection operator regressions. Better approximations of Volt'Air simulations were obtained for cattle farmyard manure (3% < relative root mean square error of prediction (RRMSEP) < 8%) than for pig slurry (17% < RRMSEP < 19%) and N solution (21% < RRMSEP < 40%). The selected meta-models included between 6 and 15 input variables related to weather conditions, soil properties and cultural practices. Because of their simplicity and their short computation time, our meta-models offer a promising alternative to process-based models for NH emission inventories at both regional and national scales. Our approach could be implemented to emulate other process-based models in other countries.
This article was published in the following journal.
Name: Journal of environmental management
A field experiment with different nitrogen fertilization rates and mitigation measures was conducted in an open-ground vegetable field on the North China Plain to investigate the effects of nitrogen a...
Application of controlled release urea (CRU) is recommended to reduce the undesirable environmental effects resulting from urea application. However, the overall effects of CRU on maize productivity a...
Electrolytic metal manganese residue leachate (EMMRL) was produced from long-term deposition of electrolytic metal manganese residue. EMMRL contains huge amount of manganese and ammonia nitrogen which...
A comparative investigation of hydroxide precipitation, sulfide precipitation, carbonate precipitation and the struvite formation process for removing manganese and ammonia nitrogen from electrolytic ...
The usage of aquatic plants represents an alternative in the treatment of residues originating from swine. In these systems, one of the N removal methods is the ammonium (NH4 +) uptake and volatilizat...
The reference technique for the conservation of gametes is storage in liquid nitrogen but new vats of nitrogen vapor (storage over liquid nitrogen) or in dry phase (storage in an insulated...
The investigators specific aim is to evaluate the changes in breath ammonia in comparison to blood ammonia and other physiologic markers after a moderate oral protein challenge in healthy ...
L-carnitine is synthesized from lysine and methionine. Postmortem concentrations of carnitine in liver, muscle, heart, kidney, and brain averaged only one-fourth to one-third those in corr...
The purpose of this study is to evaluate various methods for estimating body composition in human subjects. Each subject is evaluated by several methods that are then compared to a criter...
The current standard of care for patients with HE includes non-absorbable disaccharides(lactulose);The chemical name for lactulose is 4-O-β-D-galactopyranosyl-D-fructofuranose.The exact m...
The process in certain BACTERIA; FUNGI; and CYANOBACTERIA converting free atmospheric NITROGEN to biologically usable forms of nitrogen, such as AMMONIA; NITRATES; and amino compounds.
Enzymes that catalyze the cleavage of a carbon-nitrogen bond by means other than hydrolysis or oxidation. Subclasses are the AMMONIA-LYASES, the AMIDINE-LYASES, the amine-lyases, and other carbon-nitrogen lyases. EC 4.3.
Meta-analysis of randomized trials in which estimates of comparative treatment effects are visualized and interpreted from a network of interventions that may or may not have been evaluated directly against each other. Common considerations in network meta-analysis include conceptual and statistical heterogeneity and incoherence.
Enzymes that catalyze the joining of glutamine-derived ammonia and another molecule. The linkage is in the form of a carbon-nitrogen bond. EC 6.3.5.
Enzymes that catalyze the joining of either ammonia or an amide with another molecule, in which the linkage is in the form of a carbon-nitrogen bond. EC 6.3.1.