Journal Description
Nitrogen
Nitrogen
is an international, peer-reviewed, open access journal on the whole field of nitrogen research published quarterly online by MDPI.
- Open Access—free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within ESCI (Web of Science), Scopus, CAPlus / SciFinder, and other databases.
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 19.3 days after submission; acceptance to publication is undertaken in 4.7 days (median values for papers published in this journal in the first half of 2024).
- Journal Rank: CiteScore - Q2 (Agricultural and Biological Sciences (miscellaneous))
- Recognition of Reviewers: APC discount vouchers, optional signed peer-review and reviewer names published annually in the journal.
Impact Factor:
1.6 (2023);
5-Year Impact Factor:
1.6 (2023)
Latest Articles
Gas-Phase Photocatalytic Transformations of Nitric Oxide Using Titanium Dioxide on Glass Fiber Mesh for Real-Scale Application
Nitrogen 2024, 5(3), 610-623; https://doi.org/10.3390/nitrogen5030041 (registering DOI) - 10 Jul 2024
Abstract
In this paper, the degradation of nitric oxide (NO) in an annular laboratory reactor is presented. Preliminary experiments were performed in an annular reactor (AR) under simulated solar irradiation. Titanium dioxide (TiO2 P25) was used as a photocatalyst and immobilized on glass
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In this paper, the degradation of nitric oxide (NO) in an annular laboratory reactor is presented. Preliminary experiments were performed in an annular reactor (AR) under simulated solar irradiation. Titanium dioxide (TiO2 P25) was used as a photocatalyst and immobilized on glass fibers mesh (GM) by the sol–gel method prepared from commercially available materials. The aim of the experiments was to remove NO from the air stream. The initial rate constant of the NO photocatalytic degradation was recognized to follow mass-transfer-controlled first-order kinetics. The results confirmed the photocatalytic reduction of NO to molecular nitrogen (N2) and oxidation to nitrate. Therefore, the preliminary results obtained in this work are used for the development of a computational fluid dynamics (CFD) model (COMSOL Multiphysics v6.2). CFD calculations provide a good basis for sizing reactors at the semi-pilot and pilot levels for both indoor and outdoor air purification systems.
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Open AccessArticle
Machine-Learning Approaches in N Estimations of Fig Cultivations Based on Satellite-Born Vegetation Indices
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Karla Janeth Martínez-Macias, Aldo Rafael Martínez-Sifuentes, Selenne Yuridia Márquez-Guerrero, Arturo Reyes-González, Pablo Preciado-Rangel, Pablo Yescas-Coronado and Ramón Trucíos-Caciano
Nitrogen 2024, 5(3), 598-609; https://doi.org/10.3390/nitrogen5030040 (registering DOI) - 10 Jul 2024
Abstract
Nitrogen is one of the most important macronutrients for crops, and, in conjunction with artificial intelligence algorithms, it is possible to estimate it with the aid of vegetation indices through remote sensing. Various indices were calculated and those with a correlation of ≥0.7
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Nitrogen is one of the most important macronutrients for crops, and, in conjunction with artificial intelligence algorithms, it is possible to estimate it with the aid of vegetation indices through remote sensing. Various indices were calculated and those with a correlation of ≥0.7 were selected for subsequent use in random forest, gradient boosting, and artificial neural networks to determine their relationship with nitrogen levels measured in the laboratory. Random forest showed no relationship, yielding an R2 of zero; and gradient boosting and the classical method were similar with 0.7; whereas artificial neural networks yielded the best results with an R2 of 0.93. Thus, estimating nitrogen levels using this algorithm is reliable, by feeding it with data from the Modified Chlorophyll Absorption Ratio Index, Transformed Chlorophyll Absorption Reflectance Index, Modified Chlorophyll Absorption Ratio Index/Optimized Soil Adjusted Vegetation Index, and Transformed Chlorophyll Absorption Ratio Index/Optimized Soil Adjusted Vegetation Index
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(This article belongs to the Special Issue Nitrogen Signaling in Plants)
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Open AccessArticle
Evaluating the Effects of Reduced N Application, a Nitrification Inhibitor, and Straw Incorporation on Fertilizer-N Fates in the Maize Growing Season: A Field 15N Tracer Study
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Zhi Quan, Shanlong Li, Zhifeng Xun, Chang Liu, Dong Liu, Yanzhi Wang, Xinghan Zhao, Ming Yang, Caiyan Lu, Xin Chen and Yunting Fang
Nitrogen 2024, 5(3), 584-597; https://doi.org/10.3390/nitrogen5030039 - 5 Jul 2024
Abstract
Reducing fertilizer-N rate, applying a nitrification inhibitor (NI), and incorporating straw are widely recommended to improve N use efficiency of crops and decrease N losses. A field 15N tracer study was conducted to compare their effectiveness on fertilizer-N fates during the maize
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Reducing fertilizer-N rate, applying a nitrification inhibitor (NI), and incorporating straw are widely recommended to improve N use efficiency of crops and decrease N losses. A field 15N tracer study was conducted to compare their effectiveness on fertilizer-N fates during the maize growing season in Northeast China. The following six treatments were used: (1) no N fertilization (control); (2) 200 kg urea-N ha−1 (100%N); (3) 200 kg urea-N ha−1 and straw (100%N + S); (4) 160 kg urea-N ha−1 (80%N); (5) 160 kg urea-N ha−1 and NI (Nitrapyrin in this study) (80%N + NI); and (6) 160 kg urea-N ha−1, NI, and straw (80%N + NI + S). The results showed that the five N fertilization treatments yielded 16–25% more grain and 39–60% more crop N uptake than the control, but the differences among the five treatments were not statistically significant. Compared with the 100%N, 20% fertilizer-N reduction (80%N) decreased the 15N concentration in topsoil and plant pools but increased the proportion of plant 15N recovery at harvesting (NUE15N, 60% vs. 50%). Compared with the 80%N, NI co-application (80%N + NI) delayed soil nitrification and increased soil 15N retention at harvesting (52% vs. 36%), thereby decreasing NUE15N significantly. Straw incorporation decreased fertilizer-N retention in soil compared with NI co-application because it promoted NUE15N significantly. In conclusion, the results demonstrate that NI and straw additions are efficient strategies for stabilizing fertilizer-N in soils and potentially minimizing N loss; however, their effects on NUE15N vary and the related mechanism must be further clarified in long-term trials.
Full article
(This article belongs to the Special Issue Soil Nitrogen Cycling—a Keystone in Ecological Sustainability)
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Open AccessArticle
Spatiotemporal Dynamics of Carbon and Nitrogen in Subtropical Urban Streams (Santo André, SP, Brazil)
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Marilena M. Luciano, Rafaella M. T. Espeçoto, Roseli F. Benassi, Luís C. Schiesari, Welber S. Smith, Ângela T. Fushita and Ricardo H. Taniwaki
Nitrogen 2024, 5(3), 572-583; https://doi.org/10.3390/nitrogen5030038 - 2 Jul 2024
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Urban sprawl poses a significant threat to urban stream water quality due to impermeabilization, reduced vegetation cover, and the release of diffuse pollutants. This study evaluates water quality in seven catchments in Santo André, SP, considering seasonality. Nutrient concentrations and in situ measurements
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Urban sprawl poses a significant threat to urban stream water quality due to impermeabilization, reduced vegetation cover, and the release of diffuse pollutants. This study evaluates water quality in seven catchments in Santo André, SP, considering seasonality. Nutrient concentrations and in situ measurements were taken during both dry and rainy seasons. Comparisons were made using Kruskal–Wallis and Mann–Whitney tests. Streams showed significant differences in relation to water quality parameters. The Carapetuba, Jundiaí, and Apiaí streams were most adversely affected, underscoring the need for urgent water quality intervention (water conductivity above 500 μS/cm, dissolved oxygen below 2 mg/L, total dissolved carbon above 50 mg/L, and total dissolved nitrogen above 25 mg/L). Significant differences were observed across seasons. The dry season showed elevated temperatures (above 25 °C) and increased total dissolved carbon (above 50 mg/L) and nitrogen concentrations (above 30 mg/L), indicating reduced dilution effects from rainfall and heightened organic contamination. Conversely, the wet season demonstrated lower nutrient concentrations, emphasizing seasonal dynamics. Sustained, long-term monitoring of urban streams in Santo André and the implementation of sewage collection and treatment in irregular settlements are recommended. These measures are essential to mitigate the adverse impacts of urban expansion on water quality.
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Open AccessArticle
Increasing Wheat Protein and Yield through Sulfur Fertilization and Its Relationship with Nitrogen
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Gustavo A. Roa, Eber Addí Quintana-Obregón, Mariela González-Renteria and Dorivar A. Ruiz Diaz
Nitrogen 2024, 5(3), 553-571; https://doi.org/10.3390/nitrogen5030037 (registering DOI) - 26 Jun 2024
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Sulfur fertilization plays a crucial role in wheat (Triticum aestivum L.) production, influencing both protein concentration and grain yield. Wheat, being one of the most important food crops globally, requires efficient management of essential nutrients, including sulfur and nitrogen, to achieve optimal
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Sulfur fertilization plays a crucial role in wheat (Triticum aestivum L.) production, influencing both protein concentration and grain yield. Wheat, being one of the most important food crops globally, requires efficient management of essential nutrients, including sulfur and nitrogen, to achieve optimal production. This study aimed to quantify the effect of sulfur fertilization on wheat protein concentration and grain yield and the relationship with nitrogen through two complementary methods: a comprehensive meta-analysis and a controlled greenhouse experiment. The meta-analysis, encompassing 55 studies from 20 countries with 545 comparisons, quantified the overall response of wheat to sulfur fertilization in diverse field environments, examining the effects based on soil texture and organic matter content. The greenhouse study investigated the effects of varying sulfur application rates and sources on protein concentration and grain yield and analyzed the relationship between sulfur and nitrogen concentrations in the grain. The meta-analysis showed overall positive effects of sulfur application on both protein concentration (2.1%) and grain yield (4.2%), with the magnitude of these effects varying based on soil texture and organic matter content. Sandy soils and soils with low organic matter content exhibited the most pronounced responses to sulfur fertilization. The greenhouse experiment revealed responses of both protein concentration and grain yield to increasing sulfur application rates, indicating an optimal rate beyond which additional sulfur may not provide further benefits. A strong positive correlation between sulfur and nitrogen concentrations in the grain highlighted their interdependence in wheat nutrition. These findings emphasize the importance of considering soil properties and the sulfur–nitrogen interaction when developing site-specific sulfur fertilization strategies for wheat. The results provide valuable insights for optimizing grain yield and protein concentration, contributing to more sustainable and efficient wheat production systems.
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Open AccessArticle
Economic Analysis of Azospirillum brasilense Inoculation Associated with Enhanced-Efficiency Nitrogen Fertilizers in Corn Production in the Brazilian Amazon
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Leonardo José Damasceno, Vinicius Masala Amaral, Daiane de Cinque Mariano, Raylon Pereira Maciel, Cândido Ferreira de Oliveira Neto, Antônio Augusto Nogueira Franco, Ismael de Jesus Matos Viégas, Augusto José Silva Pedroso, Pedro Henrique Oliveira Simões and Ricardo Shigueru Okumura
Nitrogen 2024, 5(3), 544-552; https://doi.org/10.3390/nitrogen5030036 - 26 Jun 2024
Abstract
The aim of this study was to economically estimate the effect of inoculation with Azospirillum brasilense (A. brasilense) associated with enhanced efficiency nitrogen fertilizers on corn yield cultivated in the Brazilian Amazon. The experimental design used was completely randomized, in a
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The aim of this study was to economically estimate the effect of inoculation with Azospirillum brasilense (A. brasilense) associated with enhanced efficiency nitrogen fertilizers on corn yield cultivated in the Brazilian Amazon. The experimental design used was completely randomized, in a 2 × 3 × 5 factorial scheme, resulting from the combination of the presence and absence of seeds inoculated with A. brasilense, three sources of N (conventional urea, urea with NBPT, N-(n-butyl)thiophosphoric triamide, and polymer-coated urea), and five doses of N (0; 50; 100; 150; and 200 kg ha−1 of N), with six replications. Inoculation with A. brasilense promoted profit in corn, regardless of dose and the source of N applied. The urea with NBPT provided better economic return compared to polymer-coated urea and conventional urea sources, and doses of N applied in topdressing that promoted the highest economic return were 100 and 150 kg ha−1 of N, with an estimated increase of 62.33 and 135.53 bags ha−1 and increase of BRL 3253.76 and BRL 7074.88 respectively, compared to the control treatment.
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Open AccessArticle
Changes in Ammonium-to-Nitrate Ratio along Faidherbia albida Tree Age Gradients in Arenosols
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Solomon Amare, Mitiku Haile and Emiru Birhane
Nitrogen 2024, 5(3), 529-543; https://doi.org/10.3390/nitrogen5030035 - 24 Jun 2024
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Faidherbia albida can enhance the bio-physicochemical fertility of inherently infertile Arenosols. Changes in the soil ammonium (NH4+)-to-nitrate (NO3−) ratio have agricultural, environmental, and ecological implications. Thus, the present study mainly examined the changes in Arenosol NH
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Faidherbia albida can enhance the bio-physicochemical fertility of inherently infertile Arenosols. Changes in the soil ammonium (NH4+)-to-nitrate (NO3−) ratio have agricultural, environmental, and ecological implications. Thus, the present study mainly examined the changes in Arenosol NH4+/NO3− ratios, as influenced by varying Faidherbia albida tree age classes. We collected 40 composite soil samples (4 tree age classes×2 soil depths×5 replications) from 0 to 15 and 15 to 30 cm soil depths following core and auger sampling techniques. Analyses of variance have shown that the highest NH4+/NO3− ratios for soil under the old tree canopies are followed by the medium age. In contrast, the significantly lowest NH4+/NO3− ratios were recorded for soil out-of-canopy. Pearson correlation analysis revealed that the NH4+/NO3− ratio was strongly and positively correlated with clay content, total nematode abundance, the fungi/bacterial biomass ratio, cation exchange capacity, microbial biomass carbon, total nitrogen, and soil organic carbon but negative for sand content, bulk density, and pH. The increment in the plant-available forms of nitrogen might be attributed to the accumulation of biologically fixed nitrogen by the Faidherbia albida tree–Rhizobium bacteria symbiosis. The NH4+/NO3− ratio approached one in soil under the old Faidherbia albida trees. The findings suggest that (1) the ability of soil to retain NH4+ increased and (2) the rate of nitrification might be decreased due to inhibition of nitrification by direct and indirect effects of the tree on the nitrifying group of bacteria. The increment in the NH4+/NO3− ratio could also be due to the lowering of the soil’s pH in the older Faidherbia albida trees because lower pH is known to inhibit the activities of nitrifying bacteria. Moreover, maintaining older Faidherbia albida trees in farmlands could contribute to retaining nitrogen and trigger below- and above-ground communities’ successions and ultimately surpass the productivity of arid and semi-arid Arenosols.
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Open AccessArticle
Biotransforming of Poultry and Swine Slaughterhouse Waste as an Alternative Protein Source for Ruminant Feeding
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José de Jesús Perez-Bautista, Gregorio Alvarez-Fuentes, Juan Carlos Garcia-Lopez, Ricardo Martinez-Martinez, José Alejandro Roque-Jimenez, Navid Ghavipanje, Einar Vargas-Bello-Pérez and Héctor A. Lee-Rangel
Nitrogen 2024, 5(2), 518-528; https://doi.org/10.3390/nitrogen5020034 - 8 Jun 2024
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The biotransformation of poultry (PSW) and swine (SSW) slaughterhouse waste might provide protein feedstuffs, ensuring efficient ruminant systems while safeguarding the environment. The present study aimed to evaluate the potential of PSW and SSW as alternative protein feed for ruminant animals. A total
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The biotransformation of poultry (PSW) and swine (SSW) slaughterhouse waste might provide protein feedstuffs, ensuring efficient ruminant systems while safeguarding the environment. The present study aimed to evaluate the potential of PSW and SSW as alternative protein feed for ruminant animals. A total of 24 lambs [25.4 ± 3.13 kg of body weight (BW), mean ± SD] were randomly allocated to one of three groups (n = 8): a control diet formulated with typical protein ingredients (CTRL) and two diets formulated with PSW or SSW meal as a protein source. Dietary inclusion of PSW or SSW did not alter (p = 0.05) dry matter intake or final BW. However, animals fed SSW showed the highest average daily gain (ADG, p = 0.04). In addition, substituting PSW and SSW improved the feed conversation ratio (FCR, p = 0.05). There were no diet effects (p = 0.05) on N intake, while fecal N excretion increased (p = 0.03) with SSW feeding. Compared to CTRL and PSW, ingestion of SSW decreased (p = 0.001) and retained N. The digestibility of crude protein and organic matter remained unchanged (p = 0.05). Additionally, there were no differences (p = 0.05) in potential microbial protein synthesis based on either protein content (SPMp) or energy content (SPMe). Similarly, potential metabolizable protein by protein (PMp) and potential metabolizable energy by protein (PMe) were not affected (p = 0.05). Overall, both PSW and SSW positively influenced the growth performance of ewe lambs. However, further studies are warranted to explore the impact of PWS or SSW feeding on rumen function, nitrogen pollution, and protein escaping the rumen into the intestine in ruminants.
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Open AccessArticle
Nitrogen Uptake and Use Efficiency in Winter Camelina with Applied N
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Stephen Gregg, Russ W. Gesch and Axel Garcia y Garcia
Nitrogen 2024, 5(2), 509-517; https://doi.org/10.3390/nitrogen5020033 - 6 Jun 2024
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Maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotations in the upper Midwest are highly productive. However, these narrow rotations are followed by a long winter fallow period. Over time, this has contributed to the loss of agroecological functioning,
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Maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotations in the upper Midwest are highly productive. However, these narrow rotations are followed by a long winter fallow period. Over time, this has contributed to the loss of agroecological functioning, including increased ground water pollution from nitrate-nitrogen (NO3–N). Winter camelina [Camelina sativa (L.) Crantz] is a third crop that could grow during this fallow period, but its nitrogen (N) use and efficiency are not well known. A study was conducted at three locations in the U.S. upper Midwest to determine the N uptake and use efficiency of winter camelina in response to applied N and N application timing. Agronomic efficiency (AE), internal efficiency (IE), and nitrogen recovery efficiency (NRE) tended to decrease with increasing N rates, especially beyond 67 kg N ha−1 in most instances. Total N uptake ranged from 34 to 176 kg ha−1 across N rates, and was on average 1.5 fold the applied rate. Based on the observed decline in N use efficiency with increasing N rates, an application rate of 67 kg N ha−1 appears to balance efficient N use, high yield, and lower environmental risk compared to higher N rates.
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Open AccessArticle
Effects of Sheep Grazing and Nitrogen Addition on Dicotyledonous Seedling Abundance and Diversity in Alpine Meadows
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Huanhuan Dong, Yuqi Ma, Zuoyi Wang, Yuan Yang, Longxin Zhang, Xin Yin, Honglin Li, Lanping Li, Huakun Zhou, Zhen Ma and Chunhui Zhang
Nitrogen 2024, 5(2), 498-508; https://doi.org/10.3390/nitrogen5020032 - 31 May 2024
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Seedling is a crucial stage in the growth and development of plants, and the expansion and persistence of plant populations can be achieved through seed regeneration. Sheep grazing, fertilization, light, soil moisture, vegetation diversity and biomass, and litter all have potential impacts on
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Seedling is a crucial stage in the growth and development of plants, and the expansion and persistence of plant populations can be achieved through seed regeneration. Sheep grazing, fertilization, light, soil moisture, vegetation diversity and biomass, and litter all have potential impacts on species regeneration. We measured vegetation diversity, annual net primary productivity (ANPP), litter, ground photosynthetically active radiation (PAR), and soil moisture of alpine meadows under sheep grazing and nitrogen addition treatments, and studied their effects on the dicotyledonous seedling abundance and diversity using linear regression models (LMs) and structural equation models (SEMs). We found that sheep grazing reduced ANPP, increased vegetation diversity and PAR, and decreased soil moisture. Fertilization increased ANPP and litter, decreased vegetation diversity and PAR, but had no effect on soil moisture. Sheep grazing and fertilization both reduced the abundance of dicotyledonous seedlings, and simultaneously fertilization can reduce the diversity of dicotyledonous seedlings, while sheep grazing had no effect on the diversity of dicotyledonous seedlings. LMs showed that vegetation diversity, ANPP, and litter, rather than light and soil moisture, affected dicotyledonous seedling abundance and diversity. SEMs revealed that sheep grazing and fertilization indirectly influenced seedling regeneration through vegetation diversity rather than ANPP and litter. Our research will increase our understanding of the dicotyledonous plant regeneration process in alpine grasslands and facilitate the development of strategies for management and protection of alpine grassland.
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Open AccessArticle
Effects of Nitrogen Sources on Primary and Secondary Production from Annual Temperate and Tropical Pastures in Southern Brazil
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Marcelo Ascoli da Silva, Vicente José Laamon Pinto Simões, Diógenes Cecchin Silveira, Jean Victor Savian, Taíse Robinson Kunrath, Lóren Pacheco Duarte, Thais Rodrigues Coser, Petra Junklewitz and Paulo César de Faccio Carvalho
Nitrogen 2024, 5(2), 483-497; https://doi.org/10.3390/nitrogen5020031 - 31 May 2024
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Improvements in nitrogen use efficiency can be achieved through fertilizer management strategies that capitalize on nutrient synergies. However, limited research on synergies between nitrogen, sulfur, and calcium complicates understanding causal links and developing sustainable management. In this regard, the effects of different nitrogen
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Improvements in nitrogen use efficiency can be achieved through fertilizer management strategies that capitalize on nutrient synergies. However, limited research on synergies between nitrogen, sulfur, and calcium complicates understanding causal links and developing sustainable management. In this regard, the effects of different nitrogen sources on productivity and nitrogen use efficiency in Italian ryegrass (Lolium multiflorum Lam.) and pearl millet (Pennisetum glaucum (L.)), along with their impacts on forage quality and secondary production, were investigated. Treatments included: Urea (46% N), ammonium nitrate (NH4NO3; 32% N), ammonium nitrate supplemented with calcium and sulfur (NH4NO3 (+), 27% N + 5% Ca + 3.7% S), and control treatment with no N application. The application of fertilizers that combine nitrogen with calcium and sulfur enhances primary production in both winter and summer pastures. Fertilization with NH4NO3 (+) increased nitrogen use efficiency by 125% in Italian ryegrass compared to NH4NO3. However, within the framework of rotatinuous grazing management principles, optimizing plant nitrogen use efficiency does not necessarily lead to a better forage quality or animal performance. These findings highlight that using fertilizers that promote synergies among nutrients, such as the combination of nitrogen with calcium and sulfur, can bring benefits to the sustainability of pasture-based livestock production systems.
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Open AccessArticle
Spectral Index-Based Estimation of Total Nitrogen in Forage Maize: A Comparative Analysis of Machine Learning Algorithms
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Aldo Rafael Martínez-Sifuentes, Ramón Trucíos-Caciano, Nuria Aide López-Hernández, Enrique Miguel-Valle and Juan Estrada-Ávalos
Nitrogen 2024, 5(2), 468-482; https://doi.org/10.3390/nitrogen5020030 - 29 May 2024
Abstract
Nitrogen plays a fundamental role as a nutrient for the growth of leaves and the process of photosynthesis, as it directly influences the quality and yield of corn. The importance of knowing the foliar nitrogen content through Machine Learning algorithms will help determine
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Nitrogen plays a fundamental role as a nutrient for the growth of leaves and the process of photosynthesis, as it directly influences the quality and yield of corn. The importance of knowing the foliar nitrogen content through Machine Learning algorithms will help determine the efficient use of nitrogen fertilization in a context of sustainable agronomic management by avoiding Nitrogen loss and preventing it from becoming a pollutant for the soil and the atmosphere. The combination of machine learning algorithms with vegetation spectral indices is a new practice that helps estimate parameters of agricultural importance such as nitrogen. The objective of the present study was to compare random forest and neural network algorithms for estimating total plant nitrogen with spectral indices. Five spectral indices were obtained from remotely piloted aircraft systems and analyzed by mean, maximum and minimum from each sample plot to finally obtain 15 indices, and total nitrogen was estimated from the georeferenced points. The most important variables were selected with backward, forward and stepwise methods and total nitrogen estimates by laboratory were compared with random forest models and artificial neural networks. The most important indices were NDREmax and TCARImax. Using 15 spectral indices, total nitrogen with a variance of 79% and 81% with random forest and artificial neural network, respectively, was estimated. And only using NDREmax and TCARmax indices, 73% and 79% were explained by random forest and artificial neural network, respectively. It is concluded that it is possible to estimate nitrogen in forage maize with two indices and it is recommended to analyze by phenological stage and with a greater number of field data.
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(This article belongs to the Special Issue Nitrogen Management and Water-Nitrogen Interactions in Agriculture)
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Open AccessArticle
Efficiency of Nitrogen Fertilization in Millet Irrigated with Brackish Water
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Geocleber Gomes de Sousa, Francisco Hermeson Rodrigues Costa, José Thomas Machado de Sousa, Murilo de Sousa Almeida, Silas Primola Gomes, Claudivan Feitosa de Lacerda, Thales Vinicius de Araújo Viana, Samuel de Oliveira Santos, Francisco Barroso da Silva Junior, Fernando Bezerra Lopes, Sílvio Carlos Ribeiro Vieira Lima and Alexsandro Oliveira da Silva
Nitrogen 2024, 5(2), 455-467; https://doi.org/10.3390/nitrogen5020029 - 29 May 2024
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Nitrogen fertilization can provide greater nutritional support and mitigate salt stress in the millet crop. The aim of this study was to evaluate the physiological responses and agronomic performance of millet crop subjected to nitrogen fertilization and irrigation water salinity. The study was
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Nitrogen fertilization can provide greater nutritional support and mitigate salt stress in the millet crop. The aim of this study was to evaluate the physiological responses and agronomic performance of millet crop subjected to nitrogen fertilization and irrigation water salinity. The study was carried out in a greenhouse, using a completely randomized design in a 5 × 2 factorial scheme, with four replications, with five doses of nitrogen (40; 60; 80; 100 and 120 kg ha−1 of N), and two levels of electrical conductivity for the irrigation water: 0.3 and 4.0 dS m−1. We concluded that salt stress increased leaf sodium levels and had a negative impact on stalk and panicle dry mass, leaf gas exchange, mineral element concentrations (K, P, and Ca), and water use efficiency. The use of lower-salinity water associated with increased nitrogen fertilization provides greater stalk and panicle dry mass, photosynthesis, water use efficiency, chlorophyll index, leaf potassium concentration, and biomass production. The adverse effects of salt stress were evident in decreased transpiration and stomatal conductance, alongside reductions in leaf phosphorus and calcium levels, coupled with elevated leaf sodium concentrations, particularly as nitrogen fertilization rates increased in potted millet plants. These findings offer insights for devising strategies aimed at mitigating the detrimental effects of salt stress on millet plant nutrition through targeted nitrogen fertilization approaches.
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Open AccessArticle
Changes in Amino Acids Profile and Uptake on Maize Seedlings Treated with Protein Hydrolysates and Humic Substances
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Luciano Pasqualoto Canellas, Natália Aguiar Canellas, Fábio Val, Riccardo Spaccini, Pierluigi Mazzei and Fabio Lopes Olivares
Nitrogen 2024, 5(2), 439-454; https://doi.org/10.3390/nitrogen5020028 - 26 May 2024
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Protein hydrolysates (PH) and humic substances (HS) are biostimulants that promote crop growth. Despite the widening of knowledge and insights provided by research activities over the past thirty years, there are still uncertainties concerning the possible direct absorption by plants of organic nitrogen
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Protein hydrolysates (PH) and humic substances (HS) are biostimulants that promote crop growth. Despite the widening of knowledge and insights provided by research activities over the past thirty years, there are still uncertainties concerning the possible direct absorption by plants of organic nitrogen as amino acids (AA) delivered as PH and the role of HS. This study aimed to assess the impact of PH treatment on the amino acid profile of maize seedlings and the influence of HS on amino acid uptake. Maize seedlings were treated with either PH from the yeast of the sugarcane fermentation process or a synthetic mixture of amino acids mimicking the PH composition using dual-labeled amino acids (13C, 15N glutamic acid) combined with commercially available humic substances. The amino acid profile was analyzed using HPLC, and plant tissues were examined for 15N using nuclear magnetic resonance (NMR) and mass spectrometry. The application of PH stimulated maize growth, with a more significant effect observed in the presence of humic substances. The treatments significantly altered the plants’ total amino acid content and composition profile. Maize seedlings actively uptake amino acids, representing 21% of the total nitrogen composition. The ascertained improvement of amino acid uptake stimulated by humic substances is associated with their effect on the differential expression of amino permease transporters and plasma membrane H+-ATPase. PH and amino acids enhance maize growth by significantly increasing amino acid uptake. The addition of humic substances further improved the biostimulant effects.
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Open AccessArticle
Influence of an Organic Fertilizer on Agronomic Characteristics and Herbaceous Plant Diversity in a Greek Ecosystem: The Case of Cretan Dittany (Origanum dictamnus L.)
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Aikaterini Molla, Alexandra D. Solomou, Anastasia Fountouli, Evaggelia Chatzikirou, Emmanouil Stamatakis, Petros Stamatakis and Elpiniki Skoufogianni
Nitrogen 2024, 5(2), 426-438; https://doi.org/10.3390/nitrogen5020027 - 11 May 2024
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In recent years, there has been a growing tendency towards using organic fertilizers instead of chemical ones. This study aimed to evaluate the influence of the organic fertilizer, Prima Humica, on agronomic characteristics and herbaceous plant diversity on Origanum dictamnus (Dittany) cultivation. A
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In recent years, there has been a growing tendency towards using organic fertilizers instead of chemical ones. This study aimed to evaluate the influence of the organic fertilizer, Prima Humica, on agronomic characteristics and herbaceous plant diversity on Origanum dictamnus (Dittany) cultivation. A field experiment was carried out in Kalo Xorio (Lasithi, Crete) and included three different nitrogen organic fertilization schemes: 0 g/plant (T0—unfertilized), 300 g/plot (T1), and 600 g/plot (T2). Plant height, fresh and dry weight, Leaf Area Index (LAI), and plant diversity during the growing season were measured. The results showed that when the T2 treatment was compared with the unfertilized and the T1 fertilizer, the increase in plant height ranged between 9.18% and 40.61%. Moreover, the total fresh and dry weight were positively affected by the T2 treatment. The total fresh and dry weight varied from 111.6 to 239.8 g per plant and from 36.7 to 77.6 g per plant, respectively. Furthermore, LAI was ameliorated using the T2 fertilizer scheme. Concerning plant diversity, a key finding in this study is that the O. dictamnus ecosystem favors herbaceous plant species richness and Shannon’s diversity index. In total, 18 plant species in the O. dictamnus ecosystem were recorded in the study area. The most frequently occurring plants were Anthemis arvensis L. and Piptatherum miliaceum (L.) Coss. Finally, the highest Shannon’s diversity index of herbaceous plants was detected using the T2 fertilizer scheme.
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Optimization of Ammonia Nitrogen Removal and Recovery from Raw Liquid Dairy Manure Using Vacuum Thermal Stripping and Acid Absorption Process: A Modeling Approach Using Response Surface Methodology
by
Srijana Sapkota, Arif Reza and Lide Chen
Nitrogen 2024, 5(2), 409-425; https://doi.org/10.3390/nitrogen5020026 - 9 May 2024
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Dairy manure adds a substantial amount of nitrogen to wastewater due to its high levels of associated nutrients. Removal and recovery of ammonia nitrogen (NH3-N) from raw liquid dairy manure (RLDM) is greatly valued. This study was focused on the vacuum
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Dairy manure adds a substantial amount of nitrogen to wastewater due to its high levels of associated nutrients. Removal and recovery of ammonia nitrogen (NH3-N) from raw liquid dairy manure (RLDM) is greatly valued. This study was focused on the vacuum thermal stripping–acid absorption (VTS-AA) process for NH3-N from RLDM, followed by modeling and optimization. Using the response surface methodology (RSM)-based central composite design (CCD) approach, the critical operational parameters of the vacuum thermal stripping process, including temperature (50–70 °C), pH (9–11), vacuum pressure (35–55 kPa), and treatment time (60–90 min), were optimized. With the specified parameters set at temperature 69.9 °C, pH 10.5, vacuum pressure 53.5 kPa, and treatment time 64.2 min, the NH3-N removal efficiency attained was 98.58 ± 1.05%, aligning closely with the model prediction. Furthermore, the recovered ammonium sulfate ((NH4)2SO4) closely matched their commercial counterparts, confirming the effectiveness of the VTS-AA process in recovering NH3-N from RLDM. The distinct advantage of the employed technology lies in the concurrent energy demand reduction achieved by introducing a vacuum system. These findings contribute valuable insights into the practical implementation of the VTS-AA process for treating raw dairy manure, particularly in large-scale operational contexts.
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Open AccessArticle
Does the Amount of Pre-Sowing Nitrogen Fertilization Affect Sugar Beet Root Yield and Quality of Different Genotypes?
by
Ivana Varga, Antonela Markulj Kulundžić, Monika Tkalec Kojić and Manda Antunović
Nitrogen 2024, 5(2), 386-408; https://doi.org/10.3390/nitrogen5020025 - 8 May 2024
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There has always been a specific focus on nitrogen fertilization in sugar beet production due to its important effect on sugar beet root yield and quality. For stable sugar beet growth and satisfactory root yield and quality, balanced N fertilization is crucial. Thus,
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There has always been a specific focus on nitrogen fertilization in sugar beet production due to its important effect on sugar beet root yield and quality. For stable sugar beet growth and satisfactory root yield and quality, balanced N fertilization is crucial. Thus, this study aimed to investigate spring N fertilization in two seasons as the following treatments: N0—control, N1—only pre-sowing fertilization, and N2—pre-sowing with topdressing. Four different genotypes were included in the study (Serenada, Colonia, Fred, and Danton). The experiment was set up in a plain area, belonging to the temperate climate zone in Eastern Croatia (Županja and Vrbanja), with the long-term mean (LTM) (March–October) air temperature around 16 °C and the total precipitation of 515 mm. Pre-sowing N fertilization had a smaller impact on root yield in the year with higher precipitation (31% higher than LTM). Therefore, the average yields with pre-sowing fertilization (N1) and pre-sowing fertilization with top dressing (N2) were very similar and were only 7% higher than those of the control. In a season with less rainfall (29% less than LTM), pre-sowing fertilization with top dressing (N2) had a more pronounced effect on the increase in sugar beet root yield, which was 17% higher compared to that of the control treatment. The sugar beet sucrose content and quality parameters (brei impurities, loss of sugar in molasses, extractable sugar) differed when N fertilization was applied among locations in both seasons. The white sugar yield was the highest at N2 treatment with pre-sowing and topdressing N fertilization. In general, according to the average of all locations and years of research, the Serenada hybrid achieved the highest average root yield (81.1 t ha−1), while Colonia exhibited the highest root sugar content (14.5%) and white sugar yield (9.7 t ha−1).
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Open AccessArticle
Effects of Seasonal Variation on Nitrogen Use in Brazilian Cerrado Grass Communities
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Victor Camargo Keller, Erico Fernando Lopes Pereira-Silva, Sergio Tadeu Meirelles and Elisa Hardt
Nitrogen 2024, 5(2), 373-385; https://doi.org/10.3390/nitrogen5020024 - 24 Apr 2024
Abstract
In savanna ecosystems, the seasonal effects of nitrogen forms and availability, as well as their utilization by plants, influence the abundance and distribution of herbaceous species in grassland communities. This study examines seasonal effects on nitrogen availability and utilization by native grass species
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In savanna ecosystems, the seasonal effects of nitrogen forms and availability, as well as their utilization by plants, influence the abundance and distribution of herbaceous species in grassland communities. This study examines seasonal effects on nitrogen availability and utilization by native grass species in the Cerrado, a savanna ecosystem in Brazil. Ammonium and nitrate levels in soil, nitrate acquisition and transport, and Nitrate Reductase Activity (NRA) in different plant parts during dry and wet periods were assessed. Results indicated higher soil nitrate availability during the wet period, influenced by precipitation, with leaves showing a higher nitrate content compared to roots. There was seasonal modulation in nitrate reduction, with leaves being the primary site during the dry period and roots during the wet period. The studied grass species exhibited heterogeneous responses to seasonal nitrogen availability, potentially affecting community abundance patterns. Findings suggest that edaphoclimatic seasonality plays a crucial role in nitrogen distribution and utilization capacity by grass plants in the Cerrado, contributing to the understanding of these ecosystems’ ecology.
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(This article belongs to the Special Issue Nitrogen Signaling in Plants)
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Open AccessReview
Recent Advances in Application of 1D Nanomaterials for Photocatalytic Nitrogen Fixation
by
Ragesh Nath R., Shamkumar P. Deshmukh, Sachin J. Kamble and Valmiki B. Koli
Nitrogen 2024, 5(2), 349-372; https://doi.org/10.3390/nitrogen5020023 - 22 Apr 2024
Abstract
Ammonia, as the second most-produced chemical worldwide, serves diverse roles in the industrial and agricultural sectors. However, its conventional production via the Haber–Bosch process poses significant challenges, including high energy consumption and carbon dioxide emissions. In contrast, photocatalytic nitrogen (N2) fixation,
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Ammonia, as the second most-produced chemical worldwide, serves diverse roles in the industrial and agricultural sectors. However, its conventional production via the Haber–Bosch process poses significant challenges, including high energy consumption and carbon dioxide emissions. In contrast, photocatalytic nitrogen (N2) fixation, utilizing solar energy with minimal emissions, offers a promising method for sustainable ammonia synthesis. Despite ongoing efforts, photocatalytic nitrogen fixation catalysts continue to encounter challenges such as inadequate N2 adsorption, limited light absorption, and rapid photocarrier recombination. This review explores how the electronic structure and surface characteristics of one-dimensional nanomaterials could mitigate these challenges, making them promising photocatalysts for N2 fixation. The review delves into the underlying photocatalytic mechanisms of nitrogen fixation and various synthesis methods for one-dimensional nanomaterials. Additionally, it highlights the role of the high surface area of one-dimensional nanomaterials in enhancing photocatalytic performance. A comparative analysis of the photocatalytic nitrogen fixation capabilities of different one-dimensional nanomaterials is provided. Lastly, the review offers insights into potential future advancements in photocatalytic nitrogen fixation.
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(This article belongs to the Topic Carbon and Nitrogen Cycling in Agro-Ecosystems and Other Anthropogenically Maintained Ecosystems)
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Crop Rotation and Nitrogen Fertilizer on Nitrate Leaching: Insights from a Low Rainfall Study
by
Isabeli P. Bruno, Augusto G. Araújo, Gustavo H. Merten, Audilei S. Ladeira and Victor M. Pinto
Nitrogen 2024, 5(2), 329-348; https://doi.org/10.3390/nitrogen5020022 - 19 Apr 2024
Abstract
The intensive use of agricultural fertilizers containing nitrogen (N) can increase the risk of nitrate (NO3−) leaching. However, little information exists regarding its interaction with other factors that influence NO3− leaching, such as no-tillage, which is associated with
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The intensive use of agricultural fertilizers containing nitrogen (N) can increase the risk of nitrate (NO3−) leaching. However, little information exists regarding its interaction with other factors that influence NO3− leaching, such as no-tillage, which is associated with different crop rotation schemes. The objective of this study was to quantify the leachate NO3− concentration and load below the root zone in two different crop rotations under no-tillage, with and without mineral N fertilizer. The experiment was conducted in a no-tillage area in Brazil between 2018 and 2020. The factors were two crop rotations (diversified and simplified) and two N fertilization managements (with and without N fertilizer). The soil solution was collected with suction lysimeters (1 m depth), the NO3− concentration (mg L−1) was spectrophotometrically determined, and the NO3− load (kg ha−1) was calculated from the volume of water drained and the NO3− concentration. The results were categorized into 24 evaluation periods. NO3− leaching was extremely low due to low rainfall throughout the experiment, with no significant differences between the factors and treatments. In the presence of N fertilization, leaching was substantially greater when rainfall increased, and vice versa. No significant difference was observed between the crop rotation schemes, except for one period in which the simplified soybean rotation exhibited high leaching. The evaluated treatments showed less NO3− leaching during the four periods when grass species were cultivated, indicating the importance of grasses in rotation systems.
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(This article belongs to the Special Issue Nitrogen Management and Water-Nitrogen Interactions in Agriculture)
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