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In this research, a critical scientific appraisal of Near Infrared (NIR) spectroscopy for the analysis of soil and plant is presented. Near Infrared measurements in the study were collected using a KESNIR spectrometer with a scanning range of 400-1700 nm and a large scanning area. NIR was shown as the instrument of choice because of its versatility, nondestruction of sample on analysis and rapid measurement times. The focus of this study was to derive and test correlations between NIR spectra of soil and plant samples and concentrations of nutrient-related variables in these samples (as measured using conventional techniques). These NIR correlations effectively constitute a series of calibrations. The concentrations of a number of elements ( or other soil or plant physicochemical properties) will then be able to be reliably estimated on the basis of a sample's NIR spectrum alone. Part of this project is devoted to deriving calibrations, and the rest will focus on assessing how well these NIR calibrations perform, by comparison ofNIRpredicted values to those obtained using conventional chemical extraction followed by analyte-specific instrumental analysis. In order to achieve the above for soil testing, calibrations included samples from all 15 New Zealand soil orders and subsoil types, geographical regions, and land use. Most of the soil and plant samples analysed have been taken from the pool of such samples routinely submitted to AgResearch for analysis. In addition, to date, no studies have been reported in which NIR spectra have been recorded for a full range of soil orders in a country. In the case of the NIR measurements, field-moist soil and plant samples could be used, rather than dried and ground samples. This represents a considerable saving of time and effort. One aim of this project was to investigate and validate measurements for soil and plant samples by NIR using field-moist samples. This would then enable the measurement of nutrient status in the fie

In this research, a critical scientific appraisal of Near Infrared (NIR) spectroscopy for the analysis of soil and plant is presented. Near Infrared measurements in the study were collected using a KESNIR spectrometer with a scanning range of 400-1700 nm and a large scanning area. NIR was shown as the instrument of choice because of its versatility, nondestruction of sample on analysis and rapid measurement times. The focus of this study was to derive and test correlations between NIR spectra of soil and plant samples and concentrations of nutrient-related variables in these samples (as measured using conventional techniques). These NIR correlations effectively constitute a series of calibrations. The concentrations of a number of elements ( or other soil or plant physicochemical properties) will then be able to be reliably estimated on the basis of a sample's NIR spectrum alone. Part of this project is devoted to deriving calibrations, and the rest will focus on assessing how well these NIR calibrations perform, by comparison ofNIRpredicted values to those obtained using conventional chemical extraction followed by analyte-specific instrumental analysis. In order to achieve the above for soil testing, calibrations included samples from all 15 New Zealand soil orders and subsoil types, geographical regions, and land use. Most of the soil and plant samples analysed have been taken from the pool of such samples routinely submitted to AgResearch for analysis. In addition, to date, no studies have been reported in which NIR spectra have been recorded for a full range of soil orders in a country. In the case of the NIR measurements, field-moist soil and plant samples could be used, rather than dried and ground samples. This represents a considerable saving of time and effort. One aim of this project was to investigate and validate measurements for soil and plant samples by NIR using field-moist samples. This would then enable the measurement of nutrient status in the fie