scholarly journals Organic Nitrogen in Agricultural Systems

2020 ◽  
Author(s):  
Eulene Francisco da Silva ◽  
Marlenildo Ferreira Melo ◽  
Kássio Ewerton Santos Sombra ◽  
Tatiane Severo Silva ◽  
Diana Ferreira de Freitas ◽  
...  
Author(s):  
David L. Jones ◽  
John F. Farrar ◽  
Andrew J. Macdonald ◽  
Sarah J. Kemmitt ◽  
Daniel V. Murphy

1996 ◽  
Vol 12 (2) ◽  
pp. 76-85 ◽  
Author(s):  
M.A. Shepherd ◽  
E.A. Stockdale ◽  
D.S. Powlson ◽  
S.C. Jarvis

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1448
Author(s):  
André Sradnick ◽  
Carmen Feller

The prediction of nitrogen (N) mineralization or immobilization in organic fertilizers is an important tool to optimize fertilizer use, especially in intensive agricultural systems. Our aim was to derive a model to predict the N mineralization/immobilization from readily available information on the properties of organic fertilizers in farming practice. On the basis of a literature review, a characterization of organic fertilizers was performed, revealing a large variance in fertilizer properties within the defined categories and subcategories. A partial linear model was derived and used for the prediction of N mineralization/immobilization based on the type of fertilizer and the carbon (C) to organic nitrogen (Norg) ratio. Depending on the previously defined category, a strong mineralization (e.g., plant- and animal-based commercial fertilizers) or a predominant immobilization (e.g., compost and slurries) was detected. For a total of seven main categories and their subcategories, individual models were developed. This work shows that the mineralization properties of organic fertilizers can be sufficiently predicted through a simple classification into a fertilizer category and through the C to Norg ratio.


2020 ◽  
Vol 9 (4) ◽  
pp. e04942784
Author(s):  
Andrea Aline Mombach ◽  
Carla Grasiele Zanin Hegel ◽  
Rogério Luis Cansian ◽  
Sônia Beatris Balvedi Zakrzevski

The perception of a basic education of the importance of agroecological agricultural systems for human and environmental health is fundamental for changes in consumption habits, the conservation of local biodiversity and long-term social transformation. We analyzed, by utilizing a questionnaire consisting of open and closed questions, the perceptions about agroecological and conventional agricultural production systems in 360 final students of basic education residing in nine Functional Planning Regions of southern Brazil. We used classification categories for answers within thematic axes, expressed in percentages and analyzed by means of Chi-square and Kruskal-Wallis tests. In general, students recognize agroecological systems as healthier for their families and for soil and water conservation, largely because they do not use agrochemicals. However, they demonstrated difficulties when arguing their importance for the conservation of biodiversity, ecosystems and for ensuring the food security of populations. Television was the main source of information related to agroecology, mainly for students residing in rural areas, thus pointing out shortcomings in basic education regarding the approach of the theme in schools. Our results show the need to build a complex network of knowledge and discussions on agroecological agricultural systems in basic education, involving changes in student perceptions, behaviors and sustainable choices.


Author(s):  
William R. Sutton ◽  
Jitendra P. Srivastava ◽  
James E. Neumann ◽  
Peter Droogers ◽  
Brent Boehlert

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