INVESTIGATION ON THE INDIRECT CORRELATION AND

SYNERGISTIC EFFECTS OF SOIL PH AND MOISTURE

CONTENT DETECTED BY REMOTE SENSING

György FEKETE1 – Ibrahim ISSA2 – László TOLNER1 – Imre CZINKOTA1 –

Imre T. TOLNER3

1 Szent István University, Department of Soil Science and Agricultural Chemistry, Páter Károly Str. 1. H-

2100 Gödöllő, Hungary

2 Sirte University, Sirte, Libya. Post Office Box 6742

3 University of West Hungary, Faculty of Agricultural and Food Sciences, Vár 2., H-9200

Mosonmagyaróvár, Hungary

Remote sensing is a measuring method which applicable for soil characterization on agricultural areas.

Utilization of remote sensing is particularly important in the case of agricultural farming. This method is

based on the molecule- or functional groups specific absorption peaks that are measured in infrared

wavelengths over 2500 nm. Due to the high levels of disturbance of the water the measurements in this range

are only feasible on water-free samples. The absorption peaks of the reflectance spectra measured at 350 to

2500 nm range which is used in remote sensing are found far less specific. This is the near-IR range which can

excite overtone or harmonic vibrations. The most intensive absorption between 1900-2000 nm is caused by

the omnipresent water that is moisture content. The relationships between soil properties and reflectance

spectra can be determined the most effectively by using partial least-squares regression (PLSR) which takes

into account the entire spectrum. Several authors who applied this method found a relationship between the

pH of the soil and the spectral data. Since the pH cannot cause absorbance in infrared range the detected

absorption was the result of the molecular structural changes indicated by the change in the soil pH. This

means the correlation between the detected absorption and the pH is indirect. In this study we attempt to

investigate of this indirect correlation.

Keywords: hyperspectral technology, soil acidity, humidity