Technosols from Household Solid Waste to Restore Urban Residential Soils: A Case Study in Sabanalarga, Colombia

Technosols are artificial soils produced from organic and inorganic solid waste to improve soil fertility and functionality. This study evaluated the potential of Technosols produced from household waste from the Altos de Guadalupe residential complex in Colombia to fertilize green areas and promote the growth of Duranta erecta. A physical characterization of waste from 46 houses was performed to estimate per capita production (PPC) and waste composition. Technosols were produced in 20, 50, and 200 L bioreactors using recyclable organic and inorganic waste arranged in 10 layers and composted for three months. A field trial was established with two treatments, soil without Technosols (T1) and soil with Technosols (T2), with three replicates and ten plants per plot (60 plants total). Soil fertility parameters and plant growth variables were evaluated over 300 days. The PPC reached 0.56 kg·capita−1·day−1, and 56.4% of the residues were suitable for Technosol production. Technosol exhibited a pH of approximately 7.1, an organic matter content of 11.1%, and phosphorus and potassium concentrations of 50.3 mg·kg−1 and 2573 mg·kg−1, respectively. Technosol increased soil organic matter by 5.4 percentage points and improved nutrient availability. After 300 days, plant height and root dry matter in T2 were 30% and 41% higher, respectively, than in T1 (p < 0.05). These results show that the use of Technosols on a residential scale can improve urban soil fertility and plant productivity, contributing to the principles of the circular economy and Sustainable Development Goals 11 and 12.