The Spatial Variability of Soil Chemical Properties in a Selected Area of Myanmar

Abstract

Sustainable crop production requires detailed knowledge of the spatial variability of soil properties, such as soil nutrients. The primary purpose of this study was to assess the status of soil fertility by evaluating selected soil chemical properties, at Kyee Inn Village Tract, Pyinmana Township, Middle Myanmar using Geographic Information Systems (GIS). In this study soil samples were collected for the 80 grid references examined. Variables measured were soil pH, electrical conductivity (EC), cation exchange capacity (CEC), soil organic matter, and the total content of nitrogen and phosphorus. Grid size is 300 m × 300 m, covering an area of about 480 hectares, and samples were taken at a depth of 0-15cm using a Global Positioning System (GPS) to determine the coordinates of the sampling points. Soil fertility maps were generated using Inverse Distance Weighting (IDW) interpolation in ArcGIS software 10.5. Interviews were conducted with farmers to match results to soil management practices. The statistical analysis demonstrated a high variability of total nitrogen content with a coefficient of variation of 66.84%, while the soil pH and phosphorus levels showed the minimum variability in comparison to other soil properties. The pH values ranged from 5.48 to 7.58, while for phosphorus, minimum to maximum levels are 0.017% to 0.024%, respectively. Values for EC can be considered normal, with a mean value of 0.095 dS m^-1 obtained. The CEC values ranged from 2.13 to 11.05 meq100 g^-1soil. The low level of organic matter (0.2% to 1.7%) indicated a need to increase the organic matter content to ensure sustainable crop production. This study provides farmers with an effective management and decision-making model that encourages sustainable crop production.