A new approach for determining rice critical nitrogen concentration

2011 ◽  
Vol 149 (5) ◽  
pp. 633-638 ◽  
Author(s):  
R. CONFALONIERI ◽  
C. DEBELLINI ◽  
M. PIRONDINI ◽  
P. POSSENTI ◽  
L. BERGAMINI ◽  
...  
Keyword(s):  
Nutritional Status ◽  
Cropping Systems ◽  
Nitrogen Concentration ◽  
Simulation Models ◽  
Crop Models ◽  
N Concentration ◽  
Alternative Approach ◽  
Using Data ◽  
The University ◽  
Critical N Concentration

SUMMARYA reliable evaluation of crop nutritional status is crucial for supporting fertilization aiming at maximizing qualitative and quantitative aspects of production and reducing the environmental impact of cropping systems. Most of the available simulation models evaluate crop nutritional status according to the nitrogen (N) dilution law, which derives critical N concentration as a function of above-ground biomass. An alternative approach, developed during a project carried out with students of the Cropping Systems Masters course at the University of Milan, was tested and compared with existing models (N dilution law and approaches implemented in EPIC and DAISY models). The new model (MAZINGA) reproduces the effect of leaf self-shading in lowering plant N concentration (PNC) through an inverse of the fraction of radiation intercepted by the canopy. The models were tested using data collected in four rice (Oryza sativaL.) experiments carried out in Northern Italy under potential and N-limited conditions. MAZINGA was the most accurate in identifying the critical N concentration, and therefore in discriminating PNC of plants growing under N-limited and non-limited conditions, respectively. In addition, the present work proved the effectiveness of crop models when used as tools for supporting education.

scholarly journals Establishment of Critical Nitrogen Concentration Models in Winter Wheat under Different Irrigation Levels

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 556
Author(s):  
Bin-Bin Guo ◽  
Xiao-Hui Zhao ◽  
Yu Meng ◽  
Meng-Ran Liu ◽  
Jian-Zhao Duan ◽  
...  
Keyword(s):  
Field Experiments ◽  
Nitrogen Concentration ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
High Yield ◽  
N Application ◽  
N Concentration ◽  
Whole Plant ◽  
Critical Nitrogen Concentration ◽  
Critical N Concentration

The aim of this study was to verify the applicability of the critical nitrogen concentration dilution curve (Nc) of wheat grown under different irrigation conditions in the field, and discuss the feasibility of using the N nutrition index (NNI) to optimize N fertilizer application. The high-yield, medium-protein wheat varieties Zhoumai 27 and Zhoumai 22 were used in field experiments in two different locations (Zhengzhou and Shangshui) in Huang-Huai, China. Plants were grown under rainfed and irrigation conditions, with five N application rates. Nc models of the leaves, stems, and whole plant were constructed, followed by establishment of an NNI model and accumulative N deficit model (Nand). As previous research reported, our results also showed that the critical N concentration and biomass formed a power function relationship (N = aDW−b). When the biomass was the same, the critical N concentration was higher under irrigation than rainfed treatment. Meanwhile, the fitting accuracy (R2) of the Nc model was also higher under irrigation than rainfed treatment in both sites, and was higher in the stems and whole plant. The NNI calculated using the Nc model increased with increasing N application, reflecting N deficiency. Moreover, there was a significant negative linear correlation between NNI and Nand, and both indices could be uniformly modeled between locations and water treatments. The accuracy of the Nand model was highest in the whole plant, followed by the leaves and stems. The models constructed in this paper provide a theoretical basis for accurate management of N fertilizer application in wheat production.

UPAYA MENINGKATKAN AKTIVITAS DAN HASIL BELAJAR MAHASISWA MELALUI PENERAPAN MODEL PEMBELAJARAN INKUIRI PADA MATA KULIAH KONSEP DASAR IPA 2 DI PROGRAM STUDI PENDIDIKAN GURU SEKOLAH DASAR TAHUN AKADEMIK 2013/2014

2014 ◽  
Vol 3 (1) ◽  
pp. 23
Author(s):  
Mahmud Alpusari
Keyword(s):  
Initial Data ◽  
Learning Outcomes ◽  
Inquiry Learning ◽  
Learning Activities ◽  
Simple Experiment ◽  
Competency Based ◽  
Basic Concepts ◽  
Using Data ◽  
The University ◽  
Daily Test

In line with the competency-based curriculum at the University of Riau, the effort to improvelearning basic concepts of science 2 courses puts emphasis on understanding the concept ofmatter, which is based on students' learning activities through scientific inquiry.Implementation of action research consists of two cycles in PGSD JIP University of Riau onthe odd semester of 2013/2014 with 55 third semester students. Based on the research results,lecturing process by applying the model of inquiry learning, students’ activity increased inwhich in the first cycle all activities are good category except activity I and II are faircategory. Meanwhile students’ activity in first and fourth in cycle II is good category, andvery good category in second, third, fifth, and sixth activity. Temporarily student’s learningoutcomes increased from pre-tests with an average65.45 into 77,0 in daily test I and 77.45onthe daily test II. Improvement from initial data to the first cycle was 11.55, while the datafrom the beginning to the second cycle increased 12 points. In general the improvement ofstudents’learning is possible because the learning model used is inquiry learning so thatlearning becomes active which centered into students by presenting a problem, then studentsare asked to carry out a simple experiment using equipment and tools, using data, arrangingreports, communicating the results of observations based on concepts and learned principles.Keywords: Inquiry, students’ activity, learning outcomes.

scholarly journals Internally Incentivized Interdisciplinarity: Organizational Restructuring of Research and Emerging Tensions

Minerva ◽  
2021 ◽  
Author(s):  
Mikko Salmela ◽  
Miles MacLeod ◽  
Johan Munck af Rosenschöld
Keyword(s):  
Interdisciplinary Research ◽  
Interdisciplinary Collaboration ◽  
Scientific Output ◽  
Green Technology ◽  
Academic Careers ◽  
Organizational Restructuring ◽  
Structured Interviews ◽  
Using Data ◽  
The University ◽  
Internal Funding

AbstractInterdisciplinarity is widely considered necessary to solving many contemporary problems, and new funding structures and instruments have been created to encourage interdisciplinary research at universities. In this article, we study a small technical university specializing in green technology which implemented a strategy aimed at promoting and developing interdisciplinary collaboration. It did so by reallocating its internal research funds for at least five years to “research platforms” that required researchers from at least two of the three schools within the university to participate. Using data from semi-structured interviews from researchers in three of these platforms, we identify specific tensions that the strategy has generated in this case: (1) in the allocation of platform resources, (2) in the division of labor and disciplinary relations, (3) in choices over scientific output and academic careers. We further show how the particular platform format exacerbates the identified tensions in our case. We suggest that certain features of the current platform policy incentivize shallow interdisciplinary interactions, highlighting potential limits on the value of attempting to push for interdisciplinarity through internal funding.

Comparison of rotations in which barley for grain follows woollypod vetch or forage barley

1987 ◽  
Vol 108 (3) ◽  
pp. 609-615 ◽  
Author(s):  
I. Papastylianou ◽  
Th. Samios
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
N Balance ◽  
Dry Matter Yield ◽  
Soil N ◽  
Fertilizer N ◽  
Total Soil ◽  
Using Data ◽  
Total Soil N

SummaryUsing data from rotation studies in which barley or woollypod vetch were included, both cut for hay and preceding barley for grain, it is shown that forage barley gave higher dry-matter yield than woollypod vetch (3·74 v. 2·92 t/ha per year). However, the latter gave feedingstuff of higher nitrogen concentration and yield (86 kg N/ha per year for vetch v. 55 kg N/ha per year for barley). Rainfall was an important factor in controlling the yield of the two forages and the comparison between them in different years and sites. Barley following woollypod vetch gave higher grain yield than when following forage barley (2·36 v. 1·91 t/ha). Rotation sequences which included woollypod vetch had higher output of nitrogen (N) than input of fertilizer N with a positive value of 44–60 kg N/ha per year. In rotations where forage barley was followed by barley for grain the N balance between output and input was 5–6 kg N/ha. Total soil N was similar in the different rotations at the end of a 7-year period.

Total nitrogen concentration in leaves of potatoes (Solanum tuberosumL.) as an index of nutritional status

1976 ◽  
Vol 87 (2) ◽  
pp. 293-296 ◽  
Author(s):  
A. Gupta ◽  
M. C. Saxena
Keyword(s):  
Total Nitrogen ◽  
Tuber Yield ◽  
Critical Concentration ◽  
Nitrogen Concentration ◽  
Curvilinear Relationship ◽  
N Application ◽  
Total N ◽  
Potato Plants ◽  
N Concentration ◽  
Total Nitrogen Concentration

SummaryLeaf samples were collected, at weekly intervals, throughout the growing season, from potato (Solanum tuberosumL.) plants supplied with varying amounts of nitrogen (0, 60, 120, 180 and 240 kg N/ha) and analysed for total N. Application of nitrogen increased the N concentration in the green leaves at all stages of growth. There was a significant curvilinear relationship between the final tuber yield and the total N concentration in the leaves at 48–90 days after planting in 1968–9 and at 79–107 days after planting in 1969–70. The N concentration at 70–90 days after planting was consistently related to the final tuber yield in both years. Thus this period was ideal for assessing the nitrogen status of potato plants. The critical concentration of total nitrogen generally decreased with advance in age. It ranged from 4·65% at 76 days to 3·30% at 90 days during 1968–9, whereas in 1969–70 it ranged from 4·20% at 79 days to 3·80% at 93 days. During the period from 83 to 86 days the critical percentage was around 3·6% in both the years.

scholarly journals Global‐ and Local‐Scale High‐Resolution Event Catalogs for Algorithm Testing

2019 ◽  
Author(s):  
Lisa Linville ◽  
Ronald Chip Brogan ◽  
Christopher Young ◽  
Katherine Anderson Aur
Keyword(s):  
Global Scale ◽  
Local Scale ◽  
Algorithm Performance ◽  
Directional Information ◽  
Event Sequences ◽  
University Of Utah ◽  
International Monitoring ◽  
Using Data ◽  
The University ◽  
Global And Local

ABSTRACT During the development of new seismic data processing methods, the verification of potential events and associated signals can present a nontrivial obstacle to the assessment of algorithm performance, especially as detection thresholds are lowered, resulting in the inclusion of significantly more anthropogenic signals. Here, we present two 14 day seismic event catalogs, a local‐scale catalog developed using data from the University of Utah Seismograph Stations network, and a global‐scale catalog developed using data from the International Monitoring System. Each catalog was built manually to comprehensively identify events from all sources that were locatable using phase arrival timing and directional information from seismic network stations, resulting in significant increases compared to existing catalogs. The new catalogs additionally contain challenging event sequences (prolific aftershocks and small events at the detection and location threshold) and novel event types and sources (e.g., infrasound only events and long‐wall mining events) that make them useful for algorithm testing and development, as well as valuable for the unique tectonic and anthropogenic event sequences they contain.

scholarly journals Efficiency of portable chlorophyll meters in assessing the nutritional status of wheat plants

2015 ◽  
Vol 19 (12) ◽  
pp. 1148-1151 ◽  
Author(s):  
Alessana F. Schlichting ◽  
Edna M. Bonfim-Silva ◽  
Matheus de C. Silva ◽  
William Pietro-Souza ◽  
Tonny J. A. da Silva ◽  
...  
Keyword(s):  
Nutritional Status ◽  
Chlorophyll Content ◽  
Direct Determination ◽  
Probability Level ◽  
Indirect Determination ◽  
N Concentration ◽  
Randomized Design ◽  
Chlorophyll Index ◽  
Completely Randomized Design

ABSTRACT The objective of this study was to verify the efficiency of two portable chlorophyll meters (Minolta SPAD® 502 and Falker ClorofiLOG® 1030) in assessing the nutritional status of wheat plants, correlating the indices from the devices and the direct determination of chlorophyll content with the concentration of nitrogen (N) in the plant. The experiment was conducted in a greenhouse, in pots with 5 dm3 of Oxisol, in a completely randomized design, with six N doses (0, 80, 160, 240, 320 and 400 mg dm-3) and five replicates. At 47 days after emergence, the readings of SPAD and Falker indices and the quantification of chlorophyll content and N concentration in wheat plants were performed, as well as analysis of variance and correlation test, both at 0.05 probability level. The chlorophyll meters Minolta SPAD® 502 and Falker ClorofiLOG® 1030 do not differ with respect to the indirect determination of chlorophyll in wheat plants. The Falker chlorophyll index was statistically equal to the chlorophyll content. Indirect chlorophyll indices and chlorophyll content showed a high correlation with the N concentration in the plant.

scholarly journals An Architecture for Automated Verification of Academic Testimonials in E-Learning

2019 ◽  
Vol 8 (4) ◽  
pp. 2377-2383
Keyword(s):  
Success Rate ◽  
Hard Copy ◽  
Automated Verification ◽  
Online Application ◽  
Alternative Approach ◽  
E Learning ◽  
Digital Copy ◽  
The University ◽  
A Company ◽  
Manual Verification

Universities offering e-learning courses often provide their students with a hard copy of the marksheet. When that same student wants to apply for a job through the online application portal of a company, he/she must scan the marksheet and upload the scanned copy. This is a nuisance because there can be many such marksheets and not everyone has access to a scanner at home. The candidate is also required to provide the name of the University which issued the degree as well as the marks obtained, because these information cannot be extracted from the scanned marksheet image using OCR with 100% success rate due to many factors including: varying marksheet formats, presence of background watermarks, differing fonts, loss in quality during scanning, etc. The company must now manually verify each such application by matching the entered marks against the marks printed in the marksheet, which is a tedious process. In this paper, we propose an alternative approach where the data printed on the marksheet is also embedded in a digital copy of the marksheet. This digital copy, in the form of an image, can then be downloaded by the students from the University portal thereby eliminating the need for scanning. Furthermore, when this image is uploaded, the company, i.e. job provider, can easily verify the information by invoking a standard API exposed by the University (or some nodal agency), which will then extract the embedded information. This eliminates the need for any manual verification and the entire process is automated, simple, fast and hassle-free. Security features are also inherent in our approach thereby reducing any chances of fraud

scholarly journals Leveraging Student Misconceptions to Improve Teaching of Biochemistry & Cell Biology

2021 ◽  
Vol 83 (1) ◽  
pp. 5-11
Author(s):  
Travis T. Fuchs ◽  
Kevin M. Bonney ◽  
Mike Arsenault
Keyword(s):  
Cell Biology ◽  
Natural World ◽  
Learning Theories ◽  
Collaborative Approach ◽  
Evidence Based Practices ◽  
Educational Levels ◽  
Instructional Focus ◽  
Student Misconceptions ◽  
Using Data ◽  
The University

Students come to science class with many ideas of how the natural world works, some of which do not match the consensus of the scientific community and can lead to misunderstandings. Because a growing body of educational research indicates that these misconceptions can serve as resources for learning, we developed a four-point plan to leverage knowledge of common misconceptions to improve classroom teaching by refining instructional focus, providing opportunities for reflective practice, applying evidence-based practices, and promoting exploration of learning theories. By sharing this plan with our teaching colleagues, we were able to foster a collaborative approach to our and others’ practice. To do this, we compiled a resource bank of common student misconceptions using data collected from the University of Toronto’s National Biology Competition, developed a guide for using this misconception resource bank to promote best teaching practices, then shared this plan with our teaching colleagues in order to foster a collaborative approach to our pedagogy. In this article, we present the resource bank and guide and provide teaching tips that can be applied to a wide array of scientific course types and educational levels.

scholarly journals Quantifying previous SARS-CoV-2 infection through mixture modelling of antibody levels

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
C. Bottomley ◽  
M. Otiende ◽  
S. Uyoga ◽  
K. Gallagher ◽  
E. W. Kagucia ◽  
...  
Keyword(s):  
Threshold Analysis ◽  
Vaccination Strategies ◽  
Mixture Modelling ◽  
External Data ◽  
Alternative Approach ◽  
Future Burden ◽  
Previous Infection ◽  
Using Data ◽  
Antibody Levels ◽  
Crude Estimate

AbstractAs countries decide on vaccination strategies and how to ease movement restrictions, estimating the proportion of the population previously infected with SARS-CoV-2 is important for predicting the future burden of COVID-19. This proportion is usually estimated from serosurvey data in two steps: first the proportion above a threshold antibody level is calculated, then the crude estimate is adjusted using external estimates of sensitivity and specificity. A drawback of this approach is that the PCR-confirmed cases used to estimate the sensitivity of the threshold may not be representative of cases in the wider population—e.g., they may be more recently infected and more severely symptomatic. Mixture modelling offers an alternative approach that does not require external data from PCR-confirmed cases. Here we illustrate the bias in the standard threshold-based approach by comparing both approaches using data from several Kenyan serosurveys. We show that the mixture model analysis produces estimates of previous infection that are often substantially higher than the standard threshold analysis.

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