Factors Influencing the Robustness and Accuracy of Near Infrared Reflectance Spectroscopy (NIRS) Calibrations for Ps5edicting the Digestibility of Grass Silages

Infrared Reflectance ◽

Factors Influencing

Earlier studies showed the superiority of NIRS, over fibre measurements, for predicting organic matter digestibility (OMD) in vivo of grass silages. (Barber et al 1990). This system was put into routine use in ADAS in 1989 and after some initial doubts, due to the wider range of the predicted data seen, is now accepted as the best system available for routine use. However, occasional erroneous values were predicted for which there were no obvious explanations, and which resulted in occasional relatively poor repeatability. In common with all NIRS applications it was likely that the sources of the problems contributing to the errors were i) instrumental and environmental noise, ii) sample particle size effects and iii) variable moisture content of the samples. A course of investigation was undertaken with the objective of determining the effects of these on the predicted data.

Prediction of organic matter digestibility in vivo of grass silage by near infrared reflectance spectroscopy: effect of calibration method, residual moisture and particle size

Animal Feed Science and Technology ◽

10.1016/0377-8401(94)90006-x ◽

1994 ◽

Vol 50 (1-2) ◽

pp. 17-26 ◽

Cited By ~ 37

Author(s):

C.W. Baker ◽

D.I. Givens ◽

E.R. Deaville

Keyword(s):

Particle Size ◽

Near Infrared ◽

Calibration Method ◽

Infrared Reflectance ◽

Residual Moisture ◽

Grass Silage

Comparison of Near-infrared Reflectance Spectroscopy and Standard Laboratory Analysis of Turf Soil Profile

HortScience ◽

10.21273/hortsci.30.4.896b ◽

1995 ◽

Vol 30 (4) ◽

pp. 896B-896

Author(s):

Andree-Ann Couillard ◽

A.J. Turgeon ◽

J.S. Shenk ◽

M.O. Westerhaus

Keyword(s):

Particle Size ◽

Organic Matter ◽

Near Infrared ◽

Soil Characteristics ◽

Golf Course ◽

Infrared Reflectance ◽

Wet Chemical

The ability to predict moisture and organic matter contents as well as soil particle size distribution of a golf course turf media with the use of near infrared reflectance spectroscopy (NIRS) was investigated. This study compared a new quick test, NIRS, with the use of wet chemical analysis for the evaluation of different soil characteristics. Samples were taken from greens and fairways of central Pennsylvania golf courses and from two turfgrass research centers at The Pennsylvania State Univ. Fresh samples were vertically scanned by 1.27-cm increments, from 400 to 2500 nm, with a near infrared monochromator. Moisture and organic matter contents were evaluated in the laboratory. The pipette method was used to determine the particle size distribution. Correlations of 84% and higher were obtained for the sand, silt, and clay values as well as for the moisture and organic matter contents. NIRS analysis of soil characteristics could become a convenient, rapid, and inexpensive alternative to wet chemical analysis for golf course management.

Factors affecting the prediction of organic matter Digestibility of grass silage by near infrared reflectance spectroscopy

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600026209 ◽

1994 ◽

Vol 1994 ◽

pp. 73-73

Author(s):

E. R. Deaville ◽

D. L Givens

Keyword(s):

Particle Size ◽

Near Infrared ◽

Scatter Correction ◽

Infrared Reflectance ◽

Correction Procedure ◽

Grass Silage

Earlier studies (Barber et al., 1990) showed the superiority of near infrared reflectance spectroscopy (NIRS) for predicting the organic matter digestibility (OMD) in vivo of grass silage over fibre and in vitro procedures. However, during routine application occasional erroneous values were predicted for which there were no obvious reasons. Baker and Barnes (1990) reported that the likely sources of the problems contributing to the errors were instrumental and environmental noise, sample particle size effects and variable moisture content of the samples. These authors also reported that standard normal variate - detrend (SNV-D) scatter correction procedure of Barnes et al. (1989) could be used to reduce the effects of particle size variation and they also emphasised the need to test NIRS calibrations for repeatability. The purpose of the present work was to evaluate the use of the SNV-D scatter correction procedure, the techniques for reducing the sensitivity of calibrations to residual moisture and methods to improve the repeatability of the predicted OMD in vivo values of grass silage. In addition, a further objective was to compare three calibration methods, namely modified stepwise regression (MSR), modified partial least squares (MPLS) and principal component analysis (PCA).