Nitrogen Rate and Timing Effects on Collard Yield and Plant Nitrogen Concentration

jpa ◽  
1997 ◽  
Vol 10 (3) ◽  
pp. 438-441
Author(s):  
E. A. Guertal ◽  
E. van Santen
Keyword(s):  
Nitrogen Concentration ◽  
Nitrogen Rate ◽  
Plant Nitrogen ◽  
Timing Effects

Nitrogen Rate and Timing Effects on Winter Wheat Grain Yield, Grain Protein, and Economics

jpa ◽  
1990 ◽  
Vol 3 (3) ◽  
pp. 324-328 ◽  
Author(s):  
B. Vaughan ◽  
D. G. Westfall ◽  
K. A. Barbarick
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Grain Protein ◽  
Wheat Grain ◽  
Nitrogen Rate ◽  
Timing Effects

Plant nitrogen concentration and isotopic composition in residential lawns across seven US cities

Oecologia ◽  
2016 ◽  
Vol 181 (1) ◽  
pp. 271-285 ◽  
Author(s):  
T. L. E. Trammell ◽  
D. E. Pataki ◽  
J. Cavender-Bares ◽  
P. M. Groffman ◽  
S. J. Hall ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Nitrogen Concentration ◽  
Plant Nitrogen ◽  
Us Cities

scholarly journals Optimization of Nitrogen Fertilization of Subirrigated Container-grown Chrysanthemum using a Simulation Model

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 761E-761
Author(s):  
Mark V. Yelanich ◽  
John A. Biernbaum
Keyword(s):  
Nitrogen Fertilization ◽  
Root Zone ◽  
Nitrogen Concentration ◽  
N Fertilization ◽  
Pd Controller ◽  
Optimal Range ◽  
Plant Nitrogen ◽  
Wide Range ◽  
Single Fertilization ◽  
Saturated Medium

A model constructed to describe nitrogen dynamics in the root zone of subirrigated container-grown chrysanthemum was used to develop and test nitrogen fertilization strategies. The model predicts the nitrogen concentration in the root zone by numerical integration of the rates of nitrogen applied, plant nitrogen uptake, and nitrogen movement to the medium top layer. The three strategies tested were constant liquid N fertilization, proportional derivative control (PD) based upon weekly saturated medium extraction (SME) tests, or PD control based upon daily SME tests. The optimal concentration of N to apply using a single fertilization concentration was 14 mol·m–3, but resulted in greater quantities of N being applied than if PD controller strategies were used. The PD controllers were better able to maintain the predicted SME concentration within 7 to 14 mol·m–3 optimal range and reduce the overall sample variability over time. Applying 14 mol·m–3 N at every irrigation was found to be an adequate fertilization strategy over a wide range of environmental conditions because N was applied in excess of what was needed by the plant.

scholarly journals Nitrogen fertilization in banana grown on a highly weathered soil of the humid mountain region of Puerto Rico.

1969 ◽  
Vol 86 (1-2) ◽  
pp. 15-26
Author(s):  
Héber Irizarry ◽  
Ricardo Goenaga ◽  
Ulises Chardón
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Uptake ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
Maximum Yield ◽  
Leaf Nitrogen ◽  
Dry Matter Production ◽  
Nitrogen Rate ◽  
Matter Production ◽  
Nitrogen Rates

A 40-month experiment was conducted to re-evaluate the nitrogen fertilization recommendation for banana grown on a clayey, mixed isohyperthermic Aquic Haplohumults under rainfed conditions. Five nitrogen rates (0, 85,170, 255 and 340 kg/ha/crop) were arranged in a randomized compíete block design with three replications. The nitrogen treatments were applied with 24.4 kg/ha of phosphorus, 651,7 kg/ha of potassium, and a minor element mixture containing 22.7 kg/t of fertilizer. Treatments were applied every three months. Applications of magnesium alone were also applied between treatments at the rate of 55 kg/ha in the plant crop (PC) and 110 kg/ha in each of two ratoon crops (R1, R2). During growth and development of three crops we collected data of plant and bunch traits, green and oven-dry biomass weight, nitrogen concentration in various plant organs, and bunch marketable weight at harvest. Results showed that the rate x crop interaction was highly significant (P < 0,01) for total nitrogen uptake, and for nitrogen concentration in the leaf-lamina four months before bunch harvest, and significant (P < 0.05) for total dry matter production. Total nitrogen uptake, leaf nitrogen concentration, and total dry matter production linearly increased with increments in the nitrogen rates. Overall total nitrogen uptake and total dry matter production were always significantly higher in the R2 than in the PC, Regardless of the nitrogen rate, a significantly higher nutrient concentration was always found in the leaf-lamina of the R1 plants than in either the PC or the R2 plants. Crop had no significant effect on yield, but nitrogen rate significantly influenced yield. A maximum yield of 57,060 kg/ ha/crop was obtained with an estimated nitrogen application of 240 kg/ha. This amount corresponded to a leaf nitrogen concentration of between 2.75 and 2.85 g/kg. Since the maximum yield for all crops was obtained with a nitrogen application of only 240 kg/ha, we concluded that the linear response to fertilization in excess of this amount for total nitrogen uptake, nutrient concentration, and total dry matter production may be attributed to luxury consumption of nitrogen.

scholarly journals Enhancing the Nitrogen Signals of Rice Canopies across Critical Growth Stages through the Integration of Textural and Spectral Information from Unmanned Aerial Vehicle (UAV) Multispectral Imagery

2020 ◽  
Vol 12 (6) ◽  
pp. 957 ◽  
Author(s):  
Hengbiao Zheng ◽  
Jifeng Ma ◽  
Meng Zhou ◽  
Dong Li ◽  
Xia Yao ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Nitrogen Concentration ◽  
Leaf Nitrogen ◽  
Spectral Information ◽  
Growth Stages ◽  
Nitrogen Accumulation ◽  
Multispectral Imagery ◽  
Plant Nitrogen ◽  
N Nutrition ◽  
Aerial Vehicle

This paper evaluates the potential of integrating textural and spectral information from unmanned aerial vehicle (UAV)-based multispectral imagery for improving the quantification of nitrogen (N) status in rice crops. Vegetation indices (VIs), normalized difference texture indices (NDTIs), and their combination were used to estimate four N nutrition parameters leaf nitrogen concentration (LNC), leaf nitrogen accumulation (LNA), plant nitrogen concentration (PNC), and plant nitrogen accumulation (PNA). Results demonstrated that the normalized difference red-edge index (NDRE) performed best in estimating the N nutrition parameters among all the VI candidates. The optimal texture indices had comparable performance in N nutrition parameters estimation as compared to NDRE. Significant improvement for all N nutrition parameters could be obtained by integrating VIs with NDTIs using multiple linear regression. While tested across years and growth stages, the multivariate models also exhibited satisfactory estimation accuracy. For texture analysis, texture metrics calculated in the direction D3 (perpendicular to the row orientation) are recommended for monitoring row-planted crops. These findings indicate that the addition of textural information derived from UAV multispectral imagery could reduce the effects of background materials and saturation and enhance the N signals of rice canopies for the entire season.

Models of growth and development of wheat in relation to plant nitrogen

1985 ◽  
Vol 36 (4) ◽  
pp. 537 ◽  
Author(s):  
JF Angus ◽  
MW Moncur
Keyword(s):  
Developmental Stage ◽  
Growth And Development ◽  
Growth Response ◽  
Dynamic Models ◽  
Nitrogen Concentration ◽  
Developmental Rate ◽  
Plant Nitrogen ◽  
Nitrogen Concentrations ◽  
Whole Plants ◽  
Rates Of Growth

Wheat plants were grown in culture solutions differing in nitrogen concentration and transferred between the solutions at the time of floral initiation. Rates of growth and development were expressed in relation to the nitrogen concentrations of the whole plants. Growth rate increased and developmental rate decreased with increased plant nitrogen concentration, the extent depending on the developmental stage when the nitrogen was supplied, the duration of supply, and the concentration of nitrogen in the solution. Simple dynamic models fitted to the data accounted for 97% of the variation in observed biomass and 93% of the variation in rate of development. The models are based on a concept of relative nitrogen concentration, an expression of the actual nitrogen concentration of the plant in relation to the maximum and minimum possible nitrogen concentrations at a particular developmental stage. The models suggest possibilities for calculating the growth response to nitrogen fertilizer applied at any time during the development of a crop.

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