Analysis of Environmental Properties of Paddy Soils with Regard to Seasonal Variation and Farming Methods

Abstract

The aim of this study is to investigate the environmental properties of paddy soils depending on farming methods and seasonal variation. The paddy soils in 11 plots of conventional paddy and 24 plots of organic paddy were sampled and analyzed in four season of March, May, August, and October. The obtained data of soil properties were used for statistical analysis. A nalysis of variance showed that only NH4-N and P2O5 were significantly different depending on farming methods. However, the differences of all soil properties depending on seasonal variation were strongly significant. Principal component analysis also presented t hat nitrogen and phosphorus concentration in soils were more significantly influenced by seasonal variation than farming method. Electric conductivity in soil was decreased from March to October. Amounts of soil organic matter in August and October were higher than that in March and May. T-N was decreased from March to October. NH4-N and NO3-N in the soil of both conventional and organic paddy were higher in May than other seasons. T-P concentration was found to be highest in August, but P2O5 concentration was lowest in August. It can be concluded that seasonal variation should be considered for analysis and comparison o f soil environmental properties. Key words: Paddy Soil, Soil Chemical Properties, Farming Method, Seasonal Variation, Analysis of Variance, Principal Component Analysis