SOIL MANAGEMENT OPTIONS BASED ON SOIL CHARACTERISTICS OF BRACKISHWATER PONDS IN EAST LUWU REGENCY, SOUTH SULAWESI PROVINCE, INDONESIA

Akhmad Mustafa*, Hasnawi, and Tarunamulia
 
 Research Institute for Coastal Aquaculture
 Jalan Makmur Daeng Sitakka 129, Maros 90512, South Sulawesi, Indonesia
 akhmadmustafa@yahoo.com
 


East Luwu Regency is located in the east coast of South Sulawesi Province, Indonesia.  The regency has wide brackishwater ponds area, but the productivity levels of black tiger shrimp (Penaeus monodon) and milkfish (Chanos chanos) are still low.  Soil quality has been generally considered to be one of factors determining the productivity level in land-based aquaculture system.  Acid sulfate soil is dominant soil in brackishwater ponds of East Luwu Regency and it is classified as problematic soil.   The study was aimed to determine the soil characteristics of brackishwater ponds to be managed soil acidity in brackishwater ponds of  East Luwu Regency.

Soil samples were collected at a depth of 0-0.2 m in brackishwater ponds located in Burau, Wotu, Angkona, and Malili Districts. Soil quality variables measured directly in the field were pHF and pHFOX, while soil quality variables analyzed in the laboratory were pHKCl, pHox, SKCl, SP, SPOS, organic matter, pyrite, Fe, and Al. Data from soil variable characteristics were analyzed by statistical methods to obtain the average value and standard deviation.  The recommended soil management is based on soil characteritics and to be adapted to traditional technology in brackishwater ponds.

The results showed that acid sulfate soils in brackishwater ponds of East Luwu Regency were  associated with peat soils and were characterized by high concentration of organic matter (14.22±5.917%).  Acid sulfate soil in East Luwu Regency was also characterized by low pH and by a relatively high content of toxic elements (Table 1). The problem relating to soil pH and toxic elements can be managed by applying remediation techniques such as drying, submerging, and flushing brackishwater ponds soil and or  by liming. The soil drying, submerging, and flushing is recommended to be carried out from June to October when rainfall is relatively low so that drying can be more effectively done.  Also, high salinity water used for soil submerging can increase the effectiveness of soil remediation. Lime dosage is recommended based on the value of soil SPOS, neutralization efficiency and neutralization value of lime. Proper soil management is expected to increase soil productivity with minimum use of agro-inputs in order to prevent environment degradation.