Dinamika Tingkat Kesuburan Tanah pada Lahan Pasca Tambang Batubara PT Berau Coal, Berau, Kalimantan Timur

Abstract

PT Berau Coal is seriously monitor and manage each environmental impact whether on-going and/or potentially appear following mining activities for coal production, including soil fertility dynamics related with land revegetation efforts. Observations are carried out at 3 (three) different mined land revegetation of LT, <2T, 2-4T, 4-6T, 6-8T, 8-10T,> 10T, and LO. Soil fertility is evaluated by using soil chemical properties analysis following go the criteria of PPT (1983). Most of soil chemical properties except organic content of C-organic and N-total tend to have similar intense and some of them are even higher than LO. However, it does not of the observed parameters show a specific pattern. The pattern of pH, CEC, Base Saturation, and P-available tend to increase following parabolic pattern at <2T and to the maximum peak at 4-8T. After reaching peak level these parameters adversely decline with Aluminium Saturation following hyperbolic pattern. The C-organic and N-Total contents tend to increase following vegetation planting age, otherwise with the K-available in some cases. Similar dynamic of some soil chemical properties parameters prove an interaction of soil properties each other. The increase of soil fertility takes much time as indicated by revegetated land at 4-6T and 6-8T for about two years. The pH strongly correlates with other parameters, and therefore might be used as an alternative of proper indicator for soil fertility assessment of mined land. Regarding to mined land revegetation, fast-growing species is well known consuming a great amount of nutrient and require high soil fertility. For this reason, mined land revegetation effort should be supported by soil fertilization (i.e. Calcification) and/or planting various adaptable species.