Restoration of Charcoal-Site Soil Properties on Modified Land Models through Bioremediation Potential of Peanut (Arachis hypogaea L.)

Burning can substantially change vegetation status, and enhance the soil erosion of previously productive areas (Santin and Doerr, 2016). This is why bioremediation techniques have been developed to accelerate the recovery of soil properties. In this four month-long study, the bioremediation potential of peanut plants was tested in restoring charcoal-site soil properties. The experiment had three set-ups, a positive control and a control that had undergone pyrolysis for a week and then was planted with peanuts. The moisture content and pH, Nitrogen, Phosphorus and Potassium (NPK) of all soils were tested with a soil kit from the Department of Agriculture, before and after pyrolysis and after four months, which was also validated by the Bureau of Soils. In the experiment, plant morphology, mainly height, number of leaves and leaf area index (LAI) showed a linear increase all throughout the study, unlike the number of flowers. These were sporadic, with first appearance on week 4, and had a peak of 16 flowers at week 10 from 14 pods. With regard to soil properties, planting peanuts made the soil alkaline (7.3 - up from 5.8 pH after pyrolysis), while Nitrogen content increased from low to medium. In contrast, Phosphorus levels stayed high all throughout the study, while Potassium levels decreased after the pyrolysis and became deficient after four months. Moreover, the moisture content increased from 3.905 after pyrolysis, to 12.69. These results provide evidence that the peanut plant has bioremediation potential on charcoal-site soils after a four-month long treatment period.