Journal ArticleDOI
Field evaluation of the chlorophyll meter to predict yield and nitrogen concentration of switchgrass
I. C. Madakadze,Katrine A. Stewart,R. M. Madakadze,P. R. Peterson,Bruce Coulman,Donald L. Smith +5 more
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TLDR
A field study was conducted in 1995 and 1996 to evaluate the potential of chlorophyll (SPAD) meter readings to determine switchgrass N concentration and herbage yield.Abstract:
Chlorophyll meters have been used to estimate leaf chlorophyll content, and therefore nitrogen (N) status and fertilization requirements for several crops. However, until now C4 forage grasses have not been investigated in this regard. A field study was conducted in 1995 and 1996 to evaluate the potential of chlorophyll (SPAD) meter readings to determine switchgrass N concentration and herbage yield. Meter readings were taken on the top most fully expanded leaves of switchgrass grown on a free draining sandy clay loam soil (St Bernard, Typic Hapludalf) fertilized at 0, 75, or 150 kg N ha‐1. The switchgrass was either cut at the end of the season or every four or six weeks. Herbage N concentration in uncut stands declined with time while SPAD readings increased to a mid‐season maximum, beyond which they declined rapidly. The relationship between N concentration and SPAD readings was linear (r2=0.62–0.93; p<0.01) for the cut systems. Exceptforthe 1st cut under the 4‐week harvest regime, there were ...read more
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Journal ArticleDOI
New spectral indicator assessing the efficiency of crop nitrogen treatment in corn and wheat
Pengfei Chen,Pengfei Chen,Pengfei Chen,D. Haboudane,Nicolas Tremblay,Jihua Wang,Jihua Wang,Philippe Vigneault,Baoguo Li +8 more
TL;DR: In this article, the authors proposed a new spectral index to estimate plant nitrogen (N) concentration, which is a critical component of NNI calculation, using hyperspectral reflectance data collected using a ground-based spectroradiometer on corn and wheat crops at different growth stages from 2005 to 2008.
Journal ArticleDOI
Assessing newly developed and published vegetation indices for estimating rice leaf nitrogen concentration with ground- and space-based hyperspectral reflectance
TL;DR: In this article, a systematic analysis on the quantitative relationship of leaf nitrogen concentrations (LNCs) to different hyperspectral vegetation indices with multiple field experiments under varied nitrogen rates and varied types in rice (Oryza sativa L.).
Journal ArticleDOI
Effects of Nickel on Growth and Composition of Metal Micronutrients in Barley Plants Grown in Nutrient Solution
TL;DR: In this article, a hydroponic experiment was conducted in a phytotron at pH 5.5 to study the effects of nickel (Ni) on the growth and composition of metal micronutrients, such as copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), of barley (Hordeum vulgare L. Minorimugi).
Journal ArticleDOI
SPAD index for nitrogen status diagnosis and potato yield prognosis
TL;DR: The correlation betweenSPAD1 indices and tuber yield was linear and positive, showing that SPAD1 could be used as a prognostic index of potato yield.
Book ChapterDOI
Crop Monitoring Technologies to Assess Nitrogen Status
Richard H. Fox,C.L. Walthall +1 more
TL;DR: A relatively inexpensive, handheld instrument was developed in the early 1980s (SPAD meter) (Fox and Piekielek, 1998) to estimate the chlorophyll concentration of plant leaves using leaf spectral transmitt ance.
References
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Book
Principles and Procedures of Statistics: A Biometrical Approach
TL;DR: Observations probability sampling from a normal distribution comparisons involving two sample means principles of experimental design analysis of variance.
Journal ArticleDOI
Principles and Procedures of Statistics: A Biometrical Approach.
Journal ArticleDOI
Allocating leaf nitrogen for the maximization of carbon gain: Leaf age as a control on the allocation program.
TL;DR: Simulations using a biochemically-based model of leaf photosynthesis make it possible to predict the distribution of leaf nitrogen contents that maximizes photosynthetic carbon gain over the canopy of an entire plant.
Book
Analysis of Repeated Measures
Martin Crowder,David J. Hand +1 more
TL;DR: In this paper, the authors present a simple analysis of individual times response feature analysis and individual curve fitting for polynomial trends Manova, and two-stage linear models: random regression coefficients estimation and testing particular aspects examples.
Journal ArticleDOI
Maximizing daily canopy photosynthesis with respect to the leaf nitrogen allocation pattern in the canopy.
Tadaki Hirose,M. J. A. Werger +1 more
TL;DR: Redeployment of leaf nitrogen to the top of the canopy with ageing should be more effective in increasing total canopy photosynthesis in a stand with a dense canopy than in aStand with an open canopy.
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