Perspectives on the changing properties of peat soils used for agriculture: the case of Talio Hulu Village

Abstract

Rice fields in Talio Hulu Village, located in the Swamp Irrigation Area (SIA) Block B Pangkoh I, Pandih Batu District, Pulang Pisau Regency, Central Kalimantan is cleared peatlands which replanted with rice afters being abandoned for years. This paper is a review of peatland research and development in Talio Hulu Village. This paper aims to provide an overview of sequential changes of peat soils since its opening in 1983, being developed by planting rice and secondary crops, subsequently abandoned, and afterwards managed and replanted in 2020. Soil chemical properties and fertility in 1987 showed that the top layer (0-30 cm) and below (>30 cm) were very acidic (pH 3.3-3.9); C-organic 36% and 53%; N total 2.3% and 1.2%; low base cation exchange capacity, and P2O5 1.4 mg kg−1 and 0.43 mg kg−1, then the plant showed less than optimal growth. The identification of chemical properties and fertility of the top and bottom layers of the soil after rice development in 1993 showed improvements, including: decreasing soil acidity with pH H2O 3.4-4.4 and 3.3-3.7; C-organic decreased to 11.46% and 54.52%; N total 0.33-1.11% and 0.48-1.53%; P2O5 7-100 mg kg−1 and 10-15 mg kg−1. Rice yields reached 0.3-2.0 t ha−1 for local rice varieties and 0.2-2.4 t ha−1 for high-yielding varieties. The low yield of rice indicated the poor growth of rice plants measured from the high amount of empty grain. From the survey in 2020, we identified 80% of rice fields were categorized as peat and 20% as shallow peat (peat layer <100 cm). After land remediation, soil acidity decreased (pH increased) at pH 4.11 and 4.47, C-organic decreased by 34.89 % and 42.48%, P-available increased to 17.90 mg kg−1 and 22.88 mg kg−1, and no more deep peat was found. Meanwhile, rice productivity increased to 1.55-6.31 t ha−1 or 3.27 t ha−1 an average.