Evaluation of Soil Quality and Macrofauna Abundance in Three Agricultural Systems in Subak Abasan, Badung Regency

Soil quality is a key factor in supporting sustainable agricultural productivity. This study aims to evaluate soil quality and macrofauna abundance in three different agricultural systems (organic, semi-organic, and conventional) in Subak Abasan, Badung Regency. The study employed Lal's method (1994) for soil quality evaluation by analyzing 10 Minimum Data Set (MDS) parameters encompassing physical, chemical, and biological soil properties. Soil macrofauna were collected using pitfall trap and monolith (hand sorting) methods. The results showed that the Soil Quality Index (SQI) for the organic system was 18.33 (very good category), semi-organic system 20.00 (good category), and conventional system 20.00 (good category). The highest macrofauna abundance was found in the organic system with 0.693 ind/m2 and earthworm abundance of 1,696 ind/m², which were 5.66 times and 2.94 times higher respectively compared to the conventional system. The Shannon-Wiener diversity index showed the highest H' value in the organic system (1.605) with moderate category, followed by semi-organic system (1.540) and conventional system (1.312). The highest Evenness Index was found in the semi-organic system (E = 0.791 - high category) indicating a stable community, while the lowest dominance index was also in the semi-organic system (C = 0.220 - low category) indicating no species was highly dominant. Organic and semi-organic agricultural systems showed conditions more supportive of macrofauna abundance and diversity compared to the conventional system. The relationship between soil quality and macrofauna abundance indicates that biological parameters (microbial biomass-C) are better predictors of macrofauna abundance than traditional physical-chemical parameters, suggesting the need to integrate biological parameters with greater weight in soil quality assessment systems.