In situ biopore strategy with biochar–compost combinations to enhance available water content during the vegetative stage of Katokkon chili

Abstract

Enhancing soil resilience through organic matter application has emerged as a promising strategy for agricultural adaptation to the climate crisis, particularly in the cultivation of Katokkon chili (Capsicum chinense Jacq.). This study evaluated various biochar–compost dose combinations applied via the in situ biopore method on plant vegetative performance and soil water retention properties, specifically field capacity (FC) and permanent wilting point (WP). The experiment was conducted at Tallang Sura’ Village, North Toraja Regency, Indonesia, employing a split-plot design with two factors. The main plot consisted of two Katokkon varieties (Limbong and Leatung 2), while the subplot comprised six biochar:compost dose combinations (R0–R5): (0%:100%), (100%:0%), (20%:80%), (40%:60%), (60%:40%), and (80%:20%). Soil water retention was determined using the Soil Moisture–Pressure Chamber Plate method at pressures of 2.50 pF and 4.2 pF. Results revealed a significant interaction between the Katokkon Leatung 2 variety (K2) and the R3 treatment (40% biochar:60% compost, equivalent to 150 g:225 g), which produced the greatest plant height (28.08 cm) and stem diameter (5.48 mm). The R3 treatment also yielded the highest available water content (AWC) of 9.86%, corresponding to an increase in FC to 31.08% and a reduction in WP to 21.22%. These findings indicate that the combined application of Katokkon Leatung 2 and the R3 dose simultaneously improves vegetative growth and soil resilience of Katokkon chili.