Agriculture environment monitoring: rapid soil fertility evaluation by means of near infrared spectroscopy

In agricultural practices, the development of environmental controlling programs is essential in maintaining soil fertility. It should be monitored constantly in real time situation by predicting soil properties such as nutrients and mineral contents. The main purpose of this presented paper is employ the near infrared spectroscopy (NIRS) technique in determining nitrogen (N) and magnesium (Mg) content of agricultural soil rapidly and simultaneously. Near infrared spectra data of soil samples were obtained by acquiring absorbance data in wavelength range from 1000 to 2500 nm using a portable sensing device NIR with a photodiode array detector. Spectra data were enhanced using mean normalization approach to improve prediction accuracy. Further, prediction models were developed by means of partial least square regression (PLSR) followed by cross validation. The results showed that both soil fertility properties (N and Mg) can be predicted by NIRS with maximum correlation coefficient (r) were 0.93 and 0.91 for N and Mg respectively. It may conclude that NIRS technique was able to be used in agriculture environment monitoring especialy to predict soil fertility properties.