Soil quality and its implication for brackishwater pond soil management option in East Java Province, Indonesia

Abstract

East Java Province has a vast area for brackishwater pond culture, but its pond production is still low, one of the reasons is that soil management is not optimal. This study was conducted in brackishwater ponds in Sidoarjo Regency and used the previous data from the Tuban, Gresik, Lamongan, Pasuruan, and Probolinggo Regencies to obtain information about pond soil quality and offer the option of pond soil management. The variable of soil quality measured and analyzed in this study included: pH, macronutrients, micronutrients, and texture. Before data were descriptively analyzed, data analysis was previously done to detect outlier. The result of the study showed that pond soil in East Java Province belonged to volcanic soil which is characterized by neutral pH soil yet slightly acid at certain places in Pasuruan and Probolinggo Regencies, relatively low N and C content, and relatively high PO4 content and C: N ratio. Microelement content, such as Al and Fe is relatively low. Soil texture is relatively varied but generally classified as coarse. The soil management option offered is liming with agricultural lime at a dose up to 1,500 kg/ha and application of urea fertilizer at the dose of 100-150 kg/ha. The use of PO4 solubilizing bacteria is recommended to increase PO4 availability in pond soil, followed by the application of SP-35 fertilizer at the dose of 75-100 kg/ha. The use of organic fertilizer up to 2,500 kg/ha could increase organic C content and improve the soil structure of brackishwater pond, particularly in Sidoarjo, Tuban, and Probolinggo Regencies.