Spatial Variability of Soil pH and Phosphorus Content at UTP Campus

This study was done to determine the spatial variability of soil pH and
Phosphorus content at University Technology PETRONAS (UTP) in Tronoh, Perak.
This study is important to determine the spatial variability of the soil pH and
Phosphorus content that may be useful in the field management zones and could
maximize application benefits. Accurate information on the spatial variability of these
soil properties is very essential to develop site-specific management for this study
area. This study was done by applying geostatistical methods to characterize the
spatial variability of soil pH and Phosphorus at UTP campus geostatistically and
correlate it to the environment practices and characteristics. An evaluation of the scale
of variability of soil pH and Phosphorus at UTP campus was conducted using
autocorrelation analysis of 50 samples which were grid-sampled by 50m spacing. The
locations of sample were determined by geo-rid positioning done by using a Global
Positioning System (GPS) receiver. The samples were then collected at depth of 0-20
em by using soil auger and clean plastics to preserve its properties. Collection of the
soil samples was done in order to cover all types of the soil series dominant in the
study area. The soil samples were then analyzed to determine its pH and Phosphorus
content. From the laboratory results, geostatistical analyses; semivariogram and
kriging were done. The semivariogram analysis examines the autocorrelation among
the data set using GS+ software while kriging method enables mapping of soil pH and
Phosphorus content over the entire study area using Surfer32 software. Results
indicate that significant spatial variability of soil pH and Phosphorus exist. Nugget-tosill
ratio for both soil pH and Phosphorus are lower than 25%. This indicates that both
pH and Phosphorus has a strong dependency.