Mapping Indigenous Nutrient Status of Post-Eruption Soil to Support the Fertilization of Rice (Oryza sativa) in the Southern Area of Merapi Mountain, Indonesia
Eko Amiadji JULIANTO*1,2, Suntoro SUNTORO3, Widyatmani Sih DEWI3, Partoyo PARTOYO2
* Corresponding author
1 Sebelas Maret University of Surakarta, Graduate School, Doctoral Program of Agricultural Science, Surakarta, INDONESIA
2 Universitas Pembangunan Nasional Veteran Yogyakarta, Faculty of Agriculture, Department of Soil Science, Yogyakarta,
INDONESIA
3 Sebelas Maret University of Surakarta, Faculty of Agriculture, Department of Soil Science, Surakarta, INDONESIA
E-mail: ekoamiadji@yahoo.com, suntoro_uns@yahoo.co.id, wsdewi2000@gmail.com, partoyo@upnyk.ac.id
Pages: 29-38
Abstract. This study aims to discuss a technique of digital soil mapping to recommend fertilization options based on the major indigenous soil nutrients. The southern slope of Merapi Mountain in Yogyakarta, Indonesia, was selected to conduct the research. Thirty-seven areas included in five sub-districts were chosen as soil sampling locations based on a stratified purposive sampling technique. The boundary of each area on the map was delineated using the kriging method. The collected soil samples were analyzed for indigenous content of available phosphorus, total potassium, and soil base saturation. The soil data were used as a basis for creating maps of available phosphorus content, total potassium content, and soil base saturation. The criteria for evaluating the level of soil nutrient content and for proposing fertilizer recommendation were developed according to criteria acknowledged by the Indonesian Soil Research Centre [ID: Pusat Penelitian Tanah (PPT)]. Results showed that the base saturation of the soil in the study area was dominantly classified as medium (41-60%) and high (60-80%). Phosphorus (P2O5) was found very highly available (>60 mg/100g of soil) and total potassium was dominantly very low (<10 mg/100g of soil) and low (10-20 mg/100g of soil). Based on this results, fertilizer need for rice cultivation in the study area is recommended to follow recommendations revealed in map 2 of potassium chloride (KCl), which for the low potassium level area is of 50 kg/ha of KCl + harvested rice straw, whereas for the medium potassium level area is of 0 kg/ha of KCl + harvested rice straw. In conclusion, the fertilization of irrigated rice plant should not be done uniformly.
K e y w o r d s: P2O5, K2O, base saturation, kriging method, fertilization, map of recommendations, soil, Indonesia