Species, climate and fertilizer effects on grass fibre and protein in tropical environments

2009 ◽  
Vol 147 (5) ◽  
pp. 555-568 ◽  
Author(s):  
H. TRAN ◽  
P. SALGADO ◽  
P. LECOMTE

SUMMARYA 3-year experiment (2005–07) was conducted on Reunion Island (France) to evaluate the effect of species, climate and fertilization levels on fibre and protein fractions of tropical (C4; Chloris gayana and Pennisetum clandestinum) and temperate (C3; Dactylis glomerata and Lotium multiflorum) grasses. A near infrared reflectance spectroscopy (NIRS) prediction referential was developed to estimate neutral detergent fibre (NDF), acid detergent fibre (ADF), crude protein (CP), NDF insoluble protein (NDF-IP) and ADF insoluble protein (ADF-IP). The NIRS equations were then used to screen many regrowth grass samples collected at heading stage continuously for 3 years to evaluate their changes during the seasons. Results showed that grass species differed significantly in fibre and protein fractions. NDF, ADF and ADF-IP were the lowest in D. glomerata/L. multiflorum and the highest in C. gayana. The wet season was associated with higher NDF, ADF and NDF-IP in D. glomerata/L. multiflorum and lower NDF-IP in P. clandestinum. Fertilization increased the CP in C. gayana and the NDF-IP in P. clandestinum, but decreased the ADF-IP of both C. gayana and D. glomerata/L. multiflorum. Growth rate strongly changed NDF, ADF, NDF-IP and ADF-IP although no change in CP appeared. In general, NDF, ADF and NDF-IP increased with the growth rate. In contrast, the ADF-IP content decreased from slow to fast growth rate in C. gayana and D. glomerata/L. multiflorum. Growth rate changes were thus considered as a general indicator for fibre and protein fraction variations of these grasses.

Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 364 ◽  
Author(s):  
Sara Obregón-Cano ◽  
Rafael Moreno-Rojas ◽  
Ana María Jurado-Millán ◽  
María Elena Cartea-González ◽  
Antonio De Haro-Bailón

Standard wet chemistry analytical techniques currently used to determine plant fibre constituents are costly, time-consuming and destructive. In this paper the potential of near-infrared reflectance spectroscopy (NIRS) to analyse the contents of acid detergent fibre (ADF) in turnip greens and turnip tops has been assessed. Three calibration equations were developed: in the equation without mathematical treatment the coefficient of determination (R2) was 0.91, in the first-derivative treatment equation R2 = 0.95 and in the second-derivative treatment R2 = 0.96. The estimation accuracy was based on RPD (the ratio between the standard deviation and the standard error of validation) and RER (the ratio between the range of ADF of the validation as a whole and the standard error of prediction) of the external validation. RPD and RER values were of 2.75 and 9.00 for the treatment without derivative, 3.41 and 11.79 with first-derivative, and 3.10 and 11.03 with second-derivative. With the acid detergent residue spectrum the wavelengths were identified and associated with the ADF contained in the sample. The results showed a great potential of NIRS for predicting ADF content in turnip greens and turnip tops.


1998 ◽  
Vol 22 ◽  
pp. 234-237
Author(s):  
M. Herrero ◽  
N. S. Jessop

There is increasing demand to obtain fast and accurate dynamic nutritional information from forages. Near-infrared reflectance spectroscopy (NIRS) offers the possibility for obtaining such information for a range of nutritional constituents of foods. Herrero et al. (1996 and 1997) calibrated in vitro gas production measurements of a single grass species by NIRS. There would be greater practical benefit if the gas production predictions could be obtained using calibrations derived from a wide range of plant species, since a single equation could be used for all forages. The objective of this study was to investigate if in vitro gas production measurements of a broad based sample population could be calibrated by NIRS.


2021 ◽  
Vol 13 (4) ◽  
pp. 738
Author(s):  
Kirrilly Pfitzner ◽  
Renee Bartolo ◽  
Tim Whiteside ◽  
David Loewensteiner ◽  
Andrew Esparon

The miniaturisation of hyperspectral sensors for use on drones has provided an opportunity to obtain hyper temporal data that may be used to identify and monitor non-native grass species. However, a good understanding of variation in spectra for species over time is required to target such data collections. Five taxological and morphologically similar non-native grass species were hyper spectrally characterised from multitemporal spectra (17 samples over 14 months) over phenological seasons to determine their temporal spectral response. The grasses were sampled from maintained plots of homogenous non-native grass cover. A robust in situ standardised sampling method using a non-imaging field spectrometer measuring reflectance across the 350–2500 nm wavelength range was used to obtain reliable spectral replicates both within and between plots. The visible-near infrared (VNIR) to shortwave infrared (SWIR) and continuum removed spectra were utilised. The spectra were then resampled to the VNIR only range to simulate the spectral response from more affordable VNIR only hyperspectral scanners suitable to be mounted on drones. We found that species were separable compared to similar but different species. The spectral patterns were similar over time, but the spectral shape and absorption features differed between species, indicating these subtle characteristics could be used to distinguish between species. It was the late dry season and the end of the wet season that provided maximum separability of the non-native grass species sampled. Overall the VNIR-SWIR results highlighted more dissimilarity for unlike species when compared to the VNIR results alone. The SWIR is useful for discriminating species, particularly around water absorption.


2002 ◽  
Vol 2002 ◽  
pp. 172-172
Author(s):  
D. Cozzolino ◽  
A. La Manna ◽  
D. Vaz Martins

Chemical analysis have been useful in characterising both nutrient content and digestibility of forages but less useful in predicting voluntary intake by animals (Ward et al., 1982). Faeces is the product of eroding and synthesising digestive processes and consists of residues of feed and plant tissue, component of microbial and animal origin, for this reasons faeces should contain information about the amount and characteristics of the diet. Near infrared reflectance spectroscopy (NIRS) is widely used to predict quality characteristics in forages and several reports (Lyons and Stuth, 1992; Leite and Stuth, 1995, Coates, 1999) indicated that useful prediction of dietary digestibility in grazing ruminants using faecal NIRS analysis. It is assumed for different authors that rangeland herbivore faeces contains chemical bonds resulting from undigested residues and microbial fermentation and host animal digestion end products which can provide NIRS spectral information highly correlated with dietary crude protein and digestibility (Lyons and Stuth, 1992). The objective of this work was to develop NIRS equation calibrations to estimate acid detergent fibre (ADF), neutral detergent fibre (NDF) and nitrogen in faecal samples to be used as a tool to estimate diet composition in ruminant animals under grazing conditions.


1988 ◽  
Vol 18 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Carol A. Wessman ◽  
John D. Aber ◽  
David L. Peterson ◽  
Jerry M. Melillo

Near infrared reflectance spectroscopy was evaluated as a method for measuring nitrogen and lignin content in foliage of native forest and prairie species. Near infrared reflectance spectra (1590 to 2357 nm) were obtained for 163 samples of dried green leaves and leaf litter from 18 deciduous and 2 coniferous tree species. Forty additional spectra were obtained from grass species. Reflectance (R) spectra were recorded as log (1/R) and transformed to the first and second derivative of log (1/R). Multiple linear regressions, predicting wet chemistry values based on near infrared reflectance spectra, yielded correlation coefficients of 0.98 for Kjeldahl nitrogen and 0.78 for lignin, with standard errors of 0.11% for nitrogen and 2.9% for lignin. Results suggest that near infrared reflectance spectroscopy is very effective for rapid (approximately 2 min per sample) determination of foliar lignin and nitrogen and should be considered for use as a routine analytical method.


2002 ◽  
Vol 10 (4) ◽  
pp. 309-314 ◽  
Author(s):  
D. Cozzolino ◽  
A. La Manna ◽  
D. Vaz Martins

Near infrared (NIR) reflectance spectroscopy was used to predict nitrogen (N), acid detergent fibre (ADF), neutral detergent fibre (NDF) and chromium (Cr) in beef faecal samples. One hundred and twenty faecal samples were scanned in a NIRSystems 6500 monochromator instrument over the wavelength range of 400–2500 nm in reflectance. Calibration equations were developed using modified partial least squares (MPLS) with internal cross validation to avoid overfitting. The coefficient of determination in calibration ( R2cal) and the standard error in cross validation ( SECV) were 0.80 (0.74) for N, 0.92 (12.04) for ADF, 0.86 (13.5) for NDF and 0.56 (0.07) for Cr in g kg−1 dry weight, respectively. Results for validation were 0.78 ( SEP: 0.1) for N, 0.74 ( SEP: 7.5) for ADF, 0.85 ( SEP: 8.5) for NDF and 0.10 (0.09) for Cr in g kg−1 dry weight, respectively.


2016 ◽  
Vol 38 (6) ◽  
pp. 553 ◽  
Author(s):  
Trevor J. Hall ◽  
John G. McIvor ◽  
Paul Jones ◽  
David R. Smith ◽  
David G. Mayer

Managing and measuring the grazing and nutrition of cattle are required to improve the productivity and profitability of beef businesses in northern Australia. The quality and composition of the diet selected by cattle grazing in three stocking methods (continuous, extensive rotation and intensive (cell) rotation) on nine commercial properties in Queensland were estimated using near infrared reflectance spectroscopy analyses of fresh faeces; 585 faecal samples were analysed between 2005 and 2009. Sites were in two regions (north and south Queensland) and on two vegetation communities, namely brigalow (Acacia harpophylla F. Muell. ex Benth.) on clay soils and eucalypts on light-textured soil types. Pastures were dominated by perennial sown exotic grass species, predominantly Cenchrus ciliaris L. (buffel grass) at five sites and Urochloa mosambicensis (Hack.) (Sabi grass) at one site, and by native perennial tussock grasses at three sites. Seasonal profiles of dietary crude protein, dry matter digestibility, faecal nitrogen concentration, proportion of non-grass, ratio of crude protein to digestibility and an estimate of liveweight gain are presented for each stocking method. Overall, dietary crude protein, digestibility, faecal nitrogen, the crude protein : digestibility ratio and liveweight gain were significantly higher for animals grazed continuously, with short rest periods, than for animals in extensive or intensive rotations. There was a significant interaction between stocking method and pasture growing conditions, measured as a simulated growth index, for dietary crude protein and faecal nitrogen. There was no difference between stocking methods during periods when the index was <0.2, indicating no pasture growth, but during periods of active growth (index >0.5), crude protein and faecal nitrogen were higher with continuous grazing than in the extensive and intensive rotations. For cattle producers considering alternative stocking methods, the results suggest they can obtain similar ecological responses under any of the three methods and diet quality will be higher during the pasture growing period in continuously grazed pastures.


2020 ◽  
Author(s):  
Anteneh Getachew Mengistu ◽  
Gizaw Mengistu Tsidu ◽  
Gerbrand Koren ◽  
Maurits L. Kooreman ◽  
K. Folkert Boersma ◽  
...  

Abstract. The carbon cycle of tropical terrestrial vegetation plays a vital role in the storage and exchange of atmospheric CO2. But large uncertainties surround the impacts of land-use change emissions, climate warming, the frequency of droughts, and CO2 fertilization. This culminates in poorly quantified carbon stocks and carbon fluxes even for the major ecosystems of Africa (savannas, and tropical evergreen forests). Contributors to this uncertainty are the sparsity of (micro-)meteorological observations across Africa's vast land area, a lack of sufficient ground-based observation networks and validation data for CO2, and incomplete representation of important processes in numerical models. In this study, we, therefore, turn to two remotely-sensed vegetation products that have shown to correlate highly with Gross Primary Production (GPP): Sun-Induced Fluorescence (SIF) and Near-Infrared Reflectance of vegetation (NIRv). The former is available from an updated product that we recently published (SIFTER v2), which specifically improves retrievals in tropical environments. A comparison against flux tower observations of daytime-partitioned Net Ecosystem Exchange from six major biomes in Africa shows that SIF and NIRv reproduce the seasonal patterns of GPP well, resulting in correlation coefficients of > 0.9 (N = 12 months, 4 sites) over savannas in the northern and southern hemispheres. These coefficients are slightly higher than for the widely used MPI-BGC GPP products and Enhanced Vegetation Index (EVI). Similar to SIF signals in the neighboring Amazon, peak productivity occurs in the wet season coinciding with peak soil moisture, and is followed by an initial decline during the early dry season, that reverses when light availability peaks. This suggests similar leaf dynamics are at play. Spatially, SIF and NIRv show a strong linear relation (R > 0.9, N = 250 + pixels) with multi-year MPI-BGC GPP even within single biomes. Both MPI-BGC GPP and EVI show saturation relative to peak NIRv and SIF signals during high productivity months, which suggests that GPP in the most productive regions of Africa might be larger than suggested.


2015 ◽  
Vol 44 (5) ◽  
pp. 41-43
Author(s):  
M Van Zyl ◽  
GDJ Scholtz ◽  
HJ Van der Merwe ◽  
R Meeske

The obtaining of a representative sample is crucial for the application of an accurate and uniform lucerne hay grading system in South Africa. There is currently limited data available on the effect of the inside diameter of the coring probe on the chemical composition of the lucerne hay samples. A study was therefore undertaken to determine the influence of the inside diameter of a coring probe on the chemical composition of unground lucerne hay samples using the Near Infrared Reflectance Spectroscopy (NIRS) technique. Ten lucerne bales (total 40), randomly chosen from four different grades (Prime, Grade 1, 2 and 3 according to the National Lucerne Trust quality and grading system), were sampled with both a large probe (35 mm inside diameter and 520 mm long) and a small probe (12 mm inside diameter and 450 mm long). The samples with each probe were taken at approximately the same location in the bale. The samples were analysed with the NIRS for crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), ash and lignin. The model to calculate the new lucerne quality index (NLQI) from the ADF, ash and lignin, according to the National Lucerne Trust quality and grading scheme was used. Regression analysis revealed a significant relationship (r2) between the results of the large and small probe namely CP = 0.77, ADF = 0.95, NDF = 0.94, ash = 0.92, lignin = 0.87 and NLQI = 0.97. Sampling of lucerne hay with a large and small probe was irrelevant as resulted in similar chemical composition results.Keywords: Analysis grading, New Lucerne Quality Index, NIRS, quality, sampling


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