scholarly journals Rapid Detection of Urea Fertilizer Effects on VOC Emissions from Cucumber Fruits Using a MOS E-Nose Sensor Array

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 35
Author(s):  
Sana Tatli ◽  
Esmaeil Mirzaee-Ghaleh ◽  
Hekmat Rabbani ◽  
Hamed Karami ◽  
Alphus Dan Wilson
Keyword(s):  
Sensor Array ◽  
Agricultural Soils ◽  
Agricultural Practices ◽  
Fertilizer Application ◽  
Nitrogen Fertilizers ◽  
Support Vector ◽  
Voc Emissions ◽  
Urea Fertilizer ◽  
Application Rates ◽  
Vector Machines

The widespread use of nitrogen chemical fertilizers in modern agricultural practices has raised concerns over hazardous accumulations of nitrogen-based compounds in crop foods and in agricultural soils due to nitrogen overfertilization. Many vegetables accumulate and retain large amounts of nitrites and nitrates due to repeated nitrogen applications or excess use of nitrogen fertilizers. Consequently, the consumption of high-nitrate crop foods may cause health risks to humans. The effects of varying urea–nitrogen fertilizer application rates on VOC emissions from cucumber fruits were investigated using an experimental MOS electronic-nose (e-nose) device based on differences in sensor-array responses to volatile emissions from fruits, recorded following different urea fertilizer treatments. Urea fertilizer was applied to cucumber plants at treatment rates equivalent to 0, 100, 200, 300, and 400 kg/ha. Cucumber fruits were then harvested twice, 4 and 5 months after seed planting, and evaluated for VOC emissions using an e-nose technology to assess differences in smellprint signatures associated with different urea application rates. The electrical signals from the e-nose sensor array data outputs were subjected to four aroma classification methods, including: linear and quadratic discriminant analysis (LDA-QDA), support vector machines (SVM), and artificial neural networks (ANN). The results suggest that combining the MOS e-nose technology with QDA is a promising method for rapidly monitoring urea fertilizer application rates applied to cucumber plants based on changes in VOC emissions from cucumber fruits. This new monitoring tool could be useful in adjusting future urea fertilizer application rates to help prevent nitrogen overfertilization.

scholarly journals Quantifying N2O emissions from intensive grassland production: the role of synthetic fertilizer type, application rate, timing and nitrification inhibitors

2016 ◽  
Vol 154 (5) ◽  
pp. 812-827 ◽  
Author(s):  
M. J. BELL ◽  
J. M. CLOY ◽  
C. F. E. TOPP ◽  
B. C. BALL ◽  
A. BAGNALL ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Fertilizer Application ◽  
Application Rate ◽  
Nitrous Oxide Emissions ◽  
Mineral Fertilizers ◽  
Urea Fertilizer ◽  
Mitigation Options ◽  
Application Rates ◽  
The Impact ◽  
Ipcc Default

SUMMARYIncreasing recognition of the extent to which nitrous oxide (N2O) contributes to climate change has resulted in greater demand to improve quantification of N2O emissions, identify emission sources and suggest mitigation options. Agriculture is by far the largest source and grasslands, occupying c. 0·22 of European agricultural land, are a major land-use within this sector. The application of mineral fertilizers to optimize pasture yields is a major source of N2O and with increasing pressure to increase agricultural productivity, options to quantify and reduce emissions whilst maintaining sufficient grassland for a given intensity of production are required. Identification of the source and extent of emissions will help to improve reporting in national inventories, with the most common approach using the IPCC emission factor (EF) default, where 0·01 of added nitrogen fertilizer is assumed to be emitted directly as N2O. The current experiment aimed to establish the suitability of applying this EF to fertilized Scottish grasslands and to identify variation in the EF depending on the application rate of ammonium nitrate (AN). Mitigation options to reduce N2O emissions were also investigated, including the use of urea fertilizer in place of AN, addition of a nitrification inhibitor dicyandiamide (DCD) and application of AN in smaller, more frequent doses. Nitrous oxide emissions were measured from a cut grassland in south-west Scotland from March 2011 to March 2012. Grass yield was also measured to establish the impact of mitigation options on grass production, along with soil and environmental variables to improve understanding of the controls on N2O emissions. A monotonic increase in annual cumulative N2O emissions was observed with increasing AN application rate. Emission factors ranging from 1·06–1·34% were measured for AN application rates between 80 and 320 kg N/ha, with a mean of 1·19%. A lack of any significant difference between these EFs indicates that use of a uniform EF is suitable over these application rates. The mean EF of 1·19% exceeds the IPCC default 1%, suggesting that use of the default value may underestimate emissions of AN-fertilizer-induced N2O loss from Scottish grasslands. The increase in emissions beyond an application rate of 320 kg N/ha produced an EF of 1·74%, significantly different to that from lower application rates and much greater than the 1% default. An EF of 0·89% for urea fertilizer and 0·59% for urea with DCD suggests that N2O quantification using the IPCC default EF will overestimate emissions for grasslands where these fertilizers are applied. Large rainfall shortly after fertilizer application appears to be the main trigger for N2O emissions, thus applicability of the 1% EF could vary and depend on the weather conditions at the time of fertilizer application.

Evaluation of beef flavor attribute based on sensor array in tandem with support vector machines

2019 ◽  
Vol 13 (4) ◽  
pp. 2663-2671
Author(s):  
Hongmei Wang ◽  
Xiao Dan Wang ◽  
Dengyong Liu ◽  
Ying Wang ◽  
Xing Li ◽  
...  
Keyword(s):  
Support Vector Machines ◽  
Sensor Array ◽  
Support Vector ◽  
Beef Flavor ◽  
Vector Machines

scholarly journals Phosphorus Budget for a Forested-Agricultural Watershed in Korea

Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 4 ◽  
Author(s):  
Arif Reza ◽  
Jaesung Eum ◽  
Sungmin Jung ◽  
Youngsoon Choi ◽  
Changwon Jang ◽  
...  
Keyword(s):  
Management Strategies ◽  
Sewage Treatment ◽  
Agricultural Practices ◽  
Fertilizer Application ◽  
Drainage Water ◽  
Agricultural Watershed ◽  
Application Rates ◽  
P Balance ◽  
Agriculture Fertilizer ◽  
Total P

Despite increased attention to the need for sustainable agriculture, fertilizer application rates above crop requirements remain common agricultural practices in South Korea, causing eutrophication of freshwater and coastal ecosystems. The aim of this study is to quantify phosphorus (P) inputs, outputs, and retention in a forested-agricultural watershed. The P budget showed that the combined use of chemical fertilizer and organic compost was the largest source of P (97.6% of the total) followed by atmospheric wet deposition (2.1% of the total P), whereas forest export (0.2% of the total) and sewage treatment plants (STPs) (0.1% of the total) were negligible. The P outputs were crop harvesting and hydrologic export to surface water. The P balance showed that P inputs are higher than the P outputs; approximately 87% of the total P input was retained in the soils within the watershed. However, P concentrations in drainage water were still high enough to cause eutrophication of downstream reservoirs. The results provide important details on the proportion of P export and retention in the watershed. This will help efforts to improve water quality and design better management strategies for agricultural nonpoint source pollution.

scholarly journals ASSOCIATIVE NITROGEN FIXATION ACTIVATION MEANS IN AGROCENOSIS

2012 ◽  
Vol 14 ◽  
pp. 7-31
Author(s):  
V.V. Volkogon ◽  
V.V. Skoryk
Keyword(s):  
Nitrogen Fixation ◽  
Crop Production ◽  
Agricultural Soils ◽  
Agricultural Practices ◽  
Nitrogen Fertilizers ◽  
Biological Degradation ◽  
Associative Nitrogen Fixation ◽  
Production Technologies ◽  
Seed Crops ◽  
Physiologically Active Compounds

The paper overlooks the influence of various agricultural practices on associative nitrogen fixation, including pre-sowing bacterization of seed crops with active strains of associative diazotrophic bacteria, and application of nitrogen fertilizers in physiologically optimal doses in crop production technologies. The authors discuss the relation of process’s activity and plant’s genotype. Due to the biological degradation of the most agricultural soils, and a significant reduction of pool of physiologically active compounds in it, it is appropriate to use growth stimulators in order to intensify associative nitrogen fixation and plant growth.

scholarly journals The nitrogen cascade from agricultural soils to the sea: modelling nitrogen transfers at regional watershed and global scales

2013 ◽  
Vol 368 (1621) ◽  
pp. 20130123 ◽  
Author(s):  
Gilles Billen ◽  
Josette Garnier ◽  
Luis Lassaletta
Keyword(s):  
Crop Production ◽  
Agricultural Soils ◽  
High Mobility ◽  
Agricultural Practices ◽  
Nitrogen Fertilizers ◽  
Reactive Nitrogen ◽  
Human Populations ◽  
Technical Improvement ◽  
Livestock Breeding ◽  
Management Measures

The nitrogen cycle of pre-industrial ecosystems has long been remarkably closed, in spite of the high mobility of this element in the atmosphere and hydrosphere. Inter-regional and international commercial exchanges of agricultural goods, which considerably increased after the generalization of the use of synthetic nitrogen fertilizers, introduced an additional type of nitrogen mobility, which nowadays rivals the atmospheric and hydrological fluxes in intensity, and causes their enhancement at the local, regional and global scales. Eighty-five per cent of the net anthropogenic input of reactive nitrogen occurs on only 43 per cent of the land area. Modern agriculture based on the use of synthetic fertilizers and the decoupling of crop and animal production is responsible for the largest part of anthropogenic losses of reactive nitrogen to the environment. In terms of levers for better managing the nitrogen cascade, beyond technical improvement of agricultural practices tending to increase nitrogen use efficiency, or environmental engineering management measures to increase nitrogen sinks in the landscape, the need to better localize crop production and livestock breeding, on the one hand, and agriculture and food demand on the other hand, is put forward as a condition to being able to supply food to human populations while preserving environmental resources.

Response of Cacao Seedlings to Fertilizer

2018 ◽  
Vol 102 (4) ◽  
pp. 20-23
Author(s):  
Thomas Oberthür ◽  
Marianne Samson ◽  
Noel Janetski ◽  
Kate Janetski ◽  
Myles Fisher
Keyword(s):  
Seedling Growth ◽  
Agricultural Practices ◽  
Fertilizer Application ◽  
Nutrient Concentrations ◽  
Agronomic Performance ◽  
Good Agricultural Practices ◽  
Application Rates

Researchers combined a suite of good agricultural practices with fertilizer application. Modest amounts of fertilizer applied to cacao seedlings in the nursery increased seedling growth and nutrient concentrations. There were no significant responses if fertilizer application rates were doubled. Results find it likely that adequate and well-timed supplies of fertilizer nutrients in the nursery will translate into better long-term agronomic performance in farmers’ fields.

scholarly journals Effect of long-term fertilizer application on yield and concentrations of elements (N, P, K, Ca, Mg, As, Cd, Cu, Cr, Fe, Mn, Ni, Pb, Zn) in grain of spring barley

2013 ◽  
Vol 59 (No. 7) ◽  
pp. 329-334 ◽  
Author(s):  
M. Hejcman ◽  
M. Berková ◽  
E. Kunzová
Keyword(s):  
Agricultural Soils ◽  
Spring Barley ◽  
Farmyard Manure ◽  
Mineral Fertilizer ◽  
Fertilizer Application ◽  
Barley Grain ◽  
Mineral Fertilizers ◽  
Risk Elements ◽  
Application Rates

Little attention has been paid to the effect of long-term fertilizer application on concentrations of elements in grain of barley produced on the metal non-contaminated agricultural soil. In 2010, we analyzed yield and concentrations of elements in grain of spring barley in unfertilized control, mineral fertilizer application (N<sub>4</sub>P<sub>2</sub>K<sub>2</sub> &ndash; 70, 60 and<br />100 kg N, P and K per ha) and combinations of farmyard manure or poultry litter with mineral fertilizer (FMN<sub>4</sub>P<sub>2</sub>K<sub>2</sub> and PLN<sub>4</sub>P<sub>2</sub>K<sub>2</sub>) treatments in the Ruzyně Fertilizer Experiment established on Luvisol in 1955 in Prague (Czech Republic). The yield of grain ranged from 4.03 to 9.74 t/ha in the control and FMN<sub>4</sub>P<sub>2</sub>K<sub>2</sub> treatment. There was a positive effect of fertilizer application on concentrations of nitrogen, phosphorusand potassium, but no effect on concentrations of calcium and magnesium. With the exception of iron, concentrations of micro (copper and zinc) and risk elements (arsenic, cadmium, chromium, lead, manganese and nickel) were not significantly affected by the fertilizer treatments. Long-term use of organic and mineral fertilizers with appropriate application rates does not represent any risk for contamination of barley grain by risk elements on mineral rich and metal non-contaminated agricultural soils.

A Comparison of Scaling Methods to Obtain Calibrated Probabilities of Activity for Ligand-Target Predictions

2020 ◽  
Author(s):  
Lewis Mervin ◽  
Avid M. Afzal ◽  
Ola Engkvist ◽  
Andreas Bender
Keyword(s):  
Target Prediction ◽  
Support Vector ◽  
Machine Learning Method ◽  
Learning Method ◽  
Protein Target ◽  
Bioactivity Prediction ◽  
Vector Machines ◽  
Scaling Methods ◽  
Data Points ◽  
Compound Target

In the context of bioactivity prediction, the question of how to calibrate a score produced by a machine learning method into reliable probability of binding to a protein target is not yet satisfactorily addressed. In this study, we compared the performance of three such methods, namely Platt Scaling, Isotonic Regression and Venn-ABERS in calibrating prediction scores for ligand-target prediction comprising the Naïve Bayes, Support Vector Machines and Random Forest algorithms with bioactivity data available at AstraZeneca (40 million data points (compound-target pairs) across 2112 targets). Performance was assessed using Stratified Shuffle Split (SSS) and Leave 20% of Scaffolds Out (L20SO) validation.

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