Potential use of visible and near infrared reflectance spectroscopy for the estimation of nitrogen fractions in forages harvested from permanent meadows

Abstract

One-hundred and ninety-two herbage samples from permanent meadows located in the mountains of León (NW Spain) were analyzed for total nitrogen (total N), nitrogen in trichloroacetic acid precipitated matter (TCAN), borate-phosphate buffer insoluble nitrogen (BPBN), neutral-detergent insoluble nitrogen (NDIN) and acid-detergent insoluble nitrogen (ADIN). These data were used to calculate the partition of nitrogen fractions proposed by the Cornell Net Carbohydrate and Protein System (CNCPS): A (total N − TCAN), B 1 (TCAN − BPBN), B 2 (BPBN − NDIN), B 3 (NDIN − ADIN) and C (ADIN). Near-infrared reflectance spectroscopy (NIRS) technology accurately predicted total N, TCAN and NDIN, as judged by coefficient of determination (R 2 ) and ratio performance deviation (RPD) values greater than 0.90 and 2.5, respectively. The rest of the insoluble N fractions (BPBN and ADIN) were predicted with less accuracy by NIRS. Estimations of CNCPS N fractions (A, B 1 , B 2 , B 3 and C) using visible-NIR spectra of forage samples did not allow accurate predictions (R 2 < 0.90; RPD<2.5).

Assessment of Mass Flows and Fuel Quality During Mechanical Dehydration of Silages Using Near Infrared Reflectance Spectroscopy

“…The calibration results for all constituents were similar to former studies dealing with dried samples of various crops, usually without ensiling or any pre-treatment. Cozzolino et al [10] reported RSQ cal of 0.91 and a RPD factor of 4.8 for the prediction of N, whereas Valdés et al [45] and Morón et al [25] obtained better RSQ values (0.97) and RPD factors (3.9 and 8.5, respectively). For the prediction of crude lipid Berardo et al [5] found satisfying results in dried pigeon peas with SEC of 2.5 and RSQ of 0.97, whereas DeBoever et al [12] reported poor calibration results in grass silages (accounted variance of 57.3 %, SEP of 5 g/kg and SD/SEP of 1.5).…”

“…It is well known that total nitrogen (N), inorganic ash (ash), crude fibre (CF), ether extract (EE) and nitrogen free extracts (NFE) can be determined with NIRS (e.g. [32,45] as well as mineral compositions [38,33,16]. However, most studies concentrate on pure sample sets of wheat [25], maize silage [11,23], herbages, grass silages [30,2], legumes [19,9], rice [48] sunflower [26] or hemp [44].…”

In vitro ruminal degradation of neutral detergent fiber insoluble protein from tropical pastures fertilized with nitrogen

“…A situation that arise when NIRS technology is used to predict N fractions in forages. Even though, total N is well predicted by NIRS, and NDIP also has an acceptable coefficient of determination (only when there is a strong correlation with total N), the protein B3 fraction it is not well predicted given by the accumulation of errors caused by the subtraction process (23) . A recommendation is to generate NIRS calibration equations by grass specie.…”

Estimating Nitrogen Content of Corn Based on Wavelet Energy Coefficient and BP Neural Network

“…Foreign scholars have taken up research from 20 th century eighties [8,9]. In recent years, evolution about crop canopy and leaf reflection spectra and nitrogen content inversion was carried on research [10][11][12][13].Those research achieved preferable research findings. However, owing to the complexity of plant biochemistry characteristic hyperspectral response mechanism, it's a research hotspot in this field to find a more effective and sensitive diagnostic method all the times.…”