Assessment of Influence and Inter-Relationships of Soil Properties in Irrigated Rice Fields of Bangladesh by GIS and Factor Analysis

A research study was conducted assessing the influence and relationships of soil properties in irrigated rice fields of Bangladesh using 100 field plots from five land blocks and four land types of Boro (winter rice) – Fallow – T. Aman (summer rice) cropping system. Out of four land types medium highlands covered 53% of the study area whereas highland, lowland and medium lowland areas covered 26, 13 and 8% respectively; while soil groups, medium texture, moderately fine, and fine covered 68, 19 and 13% areas respectively. The clay content ranged between 9 to 47%, has significant influence on water holding capacity and nutrient leaching in irrigated rice fields. Soil pH was varied very acidic to moderately acidic with medium organic matter content of 1.8 – 2.4%. Overall soil nutrients status was poor; showing 75% area found low N, 97% area very low to low P, 90% area low to medium K, 43% area low to medium S and 50% area medium Zn status. Soil properties were grouped into four major factor components (eigenvalues >1) as: FC1-‘soil potential physical properties’ which included clay and porosity; FC2-‘soil highly potential nutrients’ which included SOM and N; FC3-‘soil moderately potential nutrients’ which included Zn and K; and FC4-‘soil additional properties’ which included S and silt. FC1 and FC2 showed highest influence on irrigated rice fields for holding water and nutrient components and causing influences on rice production.