Spatial Variability and Mapping of Soil Properties Using GIS- Based Geostatistic in Myanmar

Abstract

Precise information on the spatial variability of soil is a crucial component for productive intensive agriculture, sustainable development, and the management of natural resources. The primary purpose of the study was to investigate the spatial variability of soil properties of the study site at Yezin Agricultural University Field, Myanmar using geostatistics. A total of 94 composite soil samples were collected from a depth of 0 to 20 cm, in a systematic grid (50 x 50 m²) at the site in May 2019. Soil pH, electrical conductivity (EC), soil organic matter (SOM), total soil nitrogen (TSN), available phosphorus (Ava-P), and available potassium (Ava-K) were measured using standard analytical methods. Data were analyzed geostatistically based on semivariogram. The exponential model best fitted the semivariogram for pH, EC, Ava-P, and Ava-K; SOM was adapted from the Gaussian model while TSN was adapted from the spherical model. The nugget/sill ratio showed a strong spatial dependence exists for EC, Ava-P, and Ava-K and a moderate spatial dependence for pH, SOM, and TSN. Most of the soil was found to be strongly acidic. It was also found that EC, SOM, and Ava-P are very low in most of the study area. Most of the study area was found to have low TSN levels, while Ava-K content was low over the entire area. With such an analysis, it is possible to plan better nutrient management practices for agricultural production and environmental protection. Therefore, geostatistical analysis with ordinary kriging is a useful tool for studying the spatial variability of soil properties.