Characterization of Soil Physical Properties in Rice Fields Affected by Seawater Intrusion in Pemalang Regency

Abstract

The purpose of this study was to analyze the physical properties of rice field soil affected by seawater intrusion in Ulujami Subdistrict, Pemalang Regency. Soil samples were collected from Limbangan Village and analyzed in the laboratory in November 2024, focusing on electrical conductivity (EC), salinity, and soil pH. The EC values obtained were 7.8 mmhos/cm at the center, 7.4 mmhos/cm on the right, and 7.1 mmhos/cm on the left, exceeding the plant tolerance threshold of 4 mmhos/cm. These results indicate high dissolved salt content, classifying the area as saline soil with salinity class 2, where only salt-tolerant plants can grow and productivity may decline. The soil also showed alkaline characteristics, with pH values of 8.7 (center), 8.5 (right), and 8.2 (left). The elevated pH is associated with sodium chloride ions displacing essential soil cations such as calcium and magnesium, thereby reducing microbial water absorption and potentially disrupting nutrient balance. Overall, the EC, salinity, and pH measurements indicate that the soil fertility in this area is low, making the land less suitable for optimal rice cultivation.