Application of Organic Farming Using Compost in the Cultivation of Purple Eggplant on Suboptimal Soil

Abstract

In Maro Sebo Village, the dominant soil type is classified as suboptimal soil, namely Ultisol, which has low fertility due to its low nutrient and organic matter content. Chemical fertilizers alone are not effective in addressing problems in suboptimal soils because they only supply nutrients but do not improve low soil pH and organic matter content. Therefore, organic fertilizers such as compost, which contain organic matter and nutrients, are required. The objective of this community service activity was to improve the knowledge and skills of the community in producing compost fertilizer and applying it in organic farming, particularly in eggplant cultivation on suboptimal soil. Compost was made from a mixture of cow manure and rice straw, with phosphate rock and boiler ash or dolomite as additives. The characteristics of the suboptimal soil (Ultisol) showed a low soil pH of 4.83 (acidic), 1.16% organic C (low), 0.11% total N (low), 1.59 ppm available P (very low), and very low exchangeable bases (Ca, Mg, K, and Na) of 0.31, 0.13, 0.04, and 0.05 cmol/kg, respectively. The compost had a pH of 7.42–7.77 (neutral), 0.91–0.95% total N, 4.23–4.75% total P, 12.65–19.77% total Ca, and 4.13% total Mg. The high P, Ca, and Mg contents were derived from the addition of natural phosphate rock, boiler ash, and dolomite. Eggplant growth with compost application showed optimal performance, producing 6 fruits per plant with an average fruit weight of 321.7 grams per plant. Participants’ knowledge and skills also increased, as indicated by an improvement in average scores from 48 (pre-test) to 73.26 (post-test). This community service activity successfully enhanced community knowledge and skills in compost production and eggplant cultivation on suboptimal soil.