Research Articles
Geostatistical Analysis of Soil Properties to Support Spatial Sampling in a Paddy Growing Alfisol
Authors:
- VGD Nayanaka
- WAU VitharanaEmail WAU Vitharana
- RB Mapa
Abstract
The information on the spatial and temporal variability of soil properties is vital to improve soil management and to increase the crop productivity. This study was conducted to explore the spatial variability of agronomically important soil properties of a paddy growing tract in Pulasthigama in Polonnaruwa district of Sri Lanka. The study area consisted of 18 ha and a total of 43 soil samples were collected within the plough depth (0- 20 cm). The variability of soil clay content, organic matter, available P, pH, electrical conductivity (EC), exchangeable calcium and available zinc were investigated by means of classical and geostatistical analysis techniques. The coefficient of variation of properties ranged from 5% (pH) to 140% (Zn content). According to the calculated variograms, the available P, clay content and organic matter exhibited a highly spatially structured variability whereas a medium structured variability was observed for soil pH. Pure nugget effects were observed for both available Zn and exchangeable Ca contents indicating a dominance of a random variation. The observed spatial dependencies of soil properties can be used to support spatial sampling for detailed soil mapping and thereby it is suggested that management practices such as fertilizer application, irrigation and tillage operations can be fine tuned at a within fields scale to maximize rice crop production while minimizing the detrimental effects on environment.Key words: Rice; Semi-variogram; Site-specific soil management; Spatial variability.
DOI: 10.4038/tar.v22i1.2668
Tropical Agricultural Research Vol. 22 (1): 34-44 (2010)
- Year: 2010
- Volume: 22 Issue: 1
- Page/Article: 34-44
- DOI: 10.4038/tar.v22i1.2668
- Published on 10 Jan 2011
- Peer Reviewed