Regression modeling nitrogen fertilization requirement for maize crop by combining spectral reflectance and agronomic efficiency

The objective of this study was to evaluate the different timing, methodsof applicationand nitrogen doses in the agronomic characteristics, production components, grain yield, as well as the nutrient utilization efficiency in the maize crop. The experimental design of randomized blocks, in a factorial scheme (2 x 2 x 4) and four replicates, was used for the experiment. The treatments were two application times, (maize sowing and in V7 stage coverage); two forms of application(superficial and incorporated to the soil at 8 cm depth); and four nitrogen doses (0, 60, 120, 180 kg ha-1). The agronomic characteristics of corn, plant height, spike insertion height, stalk diameter and leaf nitrogen did not differedaccording to the seasons or the application forms, only the nitrogen doses. The components of the production, length and numberof rows per spike, number of grains per row, mass of 100 grains and grain yield presented better results with application of the nitrogen incorporated in the soil and doses of 120 to 180 kg ha-1of nitrogen. The incorporation practice and the 60 kg ha-1dose provided greater agronomic efficiency in the use of nitrogen.

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Spectral reflectance response to nitrogen fertilization in field grown corn

International Journal of Agricultural and Biological Engineering ◽

10.25165/j.ijabe.20181103.2960 ◽

2018 ◽

Vol 11 (4) ◽

pp. 102-109

Author(s):

Chuanqi Xie ◽

◽

Ce Yang ◽

Alexander Hummel Jr ◽

Gregg A Johnson ◽

...

Keyword(s):

Nitrogen Fertilization ◽

Spectral Reflectance

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Temporal dynamics of spectral reflectance and vegetation indices during canola crop cycle in southern Brazil

Ciência Rural ◽

10.1590/0103-8478cr20151403 ◽

2017 ◽

Vol 47 (1) ◽

Cited By ~ 2

Author(s):

Daniele Gutterres Pinto ◽

Denise Cybis Fontana ◽

Genei Antonio Dalmago ◽

Gilberto Rocca da Cunha ◽

Elizandro Fochesato ◽

...

Keyword(s):

Nitrogen Fertilization ◽

Spectral Reflectance ◽

Growth And Development ◽

Spectral Response ◽

Block Design ◽

Vegetation Indices ◽

Weather Conditions ◽

Southern Brazil ◽

Crop Cycle ◽

Temporal Profiles

ABSTRACT: The objective of this study was to characterize the variability of spectral reflectance and temporal profiles of vegetation indices associated with nitrogen fertilization, crop cycle periods, and weather conditions of the growing season in canola canopies in southern Brazil. An experiment was carried out during the 2013 and 2014 canola growing seasons at EMBRAPA Trigo, Passo Fundo, state of Rio Grande do Sul, Brazil. The experiment was conducted in a randomized block design with four replications. Five doses of nitrogen top dressing were used as treatments: 10, 20, 40, 80, and 160kg ha-1. Measurements were obtained with the spectroradiometer positioned above the canopy, to construct spectral reflectance curves for canola and establish temporal profiles for several vegetation indices (SR, NDVI, EVI, SAVI, and GNDVI). In addition, data on shoot dry matter were obtained and phenological stages were determined. The spectral reflectance curves of canola were reported to change with canopy growth and development. Temporal profiles of vegetation indices showed two maximum peaks, one before flowering and other after flowering. The indices SR, NDVI, EVI, SAVI, and GNDVI were able to characterize changes in the canola canopy over time, as a function of phenological phases, weather conditions, and nitrogen fertilization, throughout the development cycle. Plant growth and development, variations in crop management, and environmental conditions affect the spectral response of canola.

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Nitrogen fertilization of the forage crop: its effect on the yield and agronomic efficiency of Nitrogen

Revista Investigación Agraria. ◽

10.47840/reina20203 ◽

2020 ◽

Vol 2 (1) ◽

pp. 26-32

Author(s):

Liliana Vega-Jara ◽

Keyword(s):

Key Words ◽

Plant Height ◽

Nitrogen Fertilization ◽

Dry Matter ◽

Stem Length ◽

Agronomic Efficiency ◽

Forage Crop ◽

Significance Level ◽

Fresh Biomass ◽

Key Words Nitrogen

The goal was to evaluate the effect of nitrogen fertilization on the yield and EAN (agronomic efficiency of nitrogen) of the forage oat crop. To meet this goal, an experiment with a DBCA design was carried out, using 6 treatments: T0 (control), T1 (50-20-60), T2 (100-20-60), T3 (180-20-60), T4 (250-20-60) and T5 (350-20-60), repeated three times, in San Cristobal, Huacrachuco. The evolution of plant height, number of tillers per plant, fresh biomass, dry matter,% fiber and the agronomic efficiency of nitrogen (EAN) were determined. The data were analyzed with ANOVA and LSD test at 5% significance level. Treatments T5 and T4 reached higher values in stem length, higher yields of fresh biomass and dry matter by m2 . Fertilization did not change the number of tillers per plant and the% of fiber. However, the most optimal EAN was achieved with the dose of 100-20-60. Values higher than this dose of N could produce over fertilization without the plant using it efficiently. In conclusion, it is recommended to apply this dose (100-20-60) for having presented the best EAN, although the yields were lower with this dose, it would be the most appropriate for the efficient use of crop N. Key words: Nitrogen - San Cristobal, Huacrachuco – Forage

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Yield parameters of maize crop in response to nitrogen fertilization, application of chemical fungicides and inoculation withTrichoderma harzianum

Revista Brasileira de Tecnologia Aplicada nas Ciências Agrárias ◽

10.5935/paet.v6.n2.04 ◽

2013 ◽

Vol 6 (2) ◽

Author(s):

Maria de Lourdes Resende ◽

João Almir de Oliveira ◽

Maria Leandra Resende Castro ◽

Flávio Henrique Silveira Rabelo ◽

Carlos Henrique Silveira Rabelo

Keyword(s):

Nitrogen Fertilization ◽

Maize Crop ◽

Yield Parameters ◽

Chemical Fungicides

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Efficiency in nitrogen management using conventional and transgenic technology in the cultivation of maize

Agronomy Science and Biotechnology ◽

10.33158/asb.r124.v7.2021 ◽

2021 ◽

Vol 7 ◽

pp. 1-12

Author(s):

Ivan Ricardo Carvalho ◽

Márcio Peter ◽

Gustavo Henrique Demari ◽

Francine Lautenchleger ◽

Filipe Selau Carlos ◽

...

Keyword(s):

Grain Yield ◽

Nitrogen Fertilization ◽

Block Design ◽

Maize Yield ◽

Nitrogen Partitioning ◽

Transgenic Technology ◽

Maize Crop ◽

Randomized Block Design ◽

Genetic Technologies ◽

Set Up

The objective to evaluate the maize yield components as a function of the top-dressing nitrogen partitioning in maize plants with conventional and transgenic technology. The experiment was carried out in the agricultural crops of 2012/2013 and 2013/2014, in the municipality of Tenente Portela-RS, Brazil. The experiment was set up in a randomized block design in a factorial scheme with two genetic technologies x 11 nitrogen fertilization treatments, arranged in three replications. The treatments were composed of top-dressing applications in the phenological stages V2 - two fully expanded leaves, (V2), V4 - four fully expanded leaves, (V4), V6 - six fully expanded leaves (V6) and V8 - with eight fully expanded leaves (V8) and split applications in V2+V4; V2+V6; V2+V8; V4+V6; V4+V8; V6+V8; and V2+V4+V6+V8. There was interaction between genetic technologies and levels of nitrogen fertilization in the maize crop. The highest grain yield was obtained with conventional technology because it presented plants with greater prolificacy, ear diameter and number of grains per row. Grain yield was superior with nitrogen fertilization in V4 and in nitrogen splitting in the V4 + V6, V4 + V8 and V2 + V4 + V6 + V8 stages.

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The effect of nitrogen fertilization on yield efficiency and quality of tubers potato varieties cultivated in an integrated production system

Biuletyn Instytutu Hodowli i Aklimatyzacji Roślin ◽

10.37317/biul-2020-0002 ◽

2020 ◽

pp. 15-22

Author(s):

Cezary Trawczyński

Keyword(s):

Nitrogen Uptake ◽

Nitrogen Fertilization ◽

Tuber Yield ◽

Total Yield ◽

Weather Conditions ◽

Utilization Efficiency ◽

Agronomic Efficiency ◽

Potato Varieties ◽

Yield Structure

The aim of the research conducted in the years 2016 – 2018 was to perform the effect of nitrogen on the total yield and quality evaluation of edible and starch potato varieties harvested after tuber maturity, as well as to establish fertilization efficiency indices. The quality of tubers was expressed: yield structure, share of deformations, content of starch and nitrates (V), but the nitrogen utilization efficiency as agronomic efficiency (AE) and fertilizer recovery efficiency (FRE) in tubers. Two experimental factors were researched: nitrogen doses (0, 50,100, 150 kg·ha-1) and varieties (Impresja, Mazur, Otolia, Szyper and Widawa) tested under different weather conditions. The total yield fresh matter between nitrogen doses ranged from 42.8 to 53.7 t·ha-1 and for varieties from 42.1 (var. Szyper) to 54.8 t·ha-1 (var. Impresja). Increasing nitrogen doses caused an increase share in the yield structure big tubers (diameter above 60 mm), nitrates (V) and total nitrogen content and nitrogen uptake with tuber yield, but decrease starch content and nitrogen fertilization efficiency indicators. On the basis of quadratic function parameters, it was shown that the varieties of Impresja, Szyper and Otolia were characterized by greater requirements in relation to the optimal nitrogen dose than the varieties of Mazur and Widawa. More assessed features determined the weather conditions during the growing season than the factors studied: the nitrogen fertilization dose and the variety. In the year with the highest amount of rainfall in relation to the average of many years, the largest decrease was recorded: tuber yield, share of big tubers in the yield structure, nitrogen uptake and agronomic efficiency. Year with the most rainfall was characterized by the highest reduction the yield of tubers, share big tubers in the yield structure, nitrogen uptake and its agronomic efficiency.

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