Work

Self-Organizing Map-Based Assessment of Compost Maturity and Cu/Zn Passivation in Biochar-Amended Pig Manure

Year: 2025

Type: article

Abstract: The accumulation of copper (Cu) and zinc (Zn) from piglet feed, coupled with inadequate compost maturation, hinders the safe land application of pig manure (PM). This study employed self-organizing maps (SOMs) integrated with three-dimensional excitation–emission matrix fluorescence spectroscopy (3D-EEM) and parallel factor analysis (PARAFAC) to evaluate PM compost maturity and Cu/Zn passivation under different biochar (BC) dosages (0%, 8%, 10%, and 12%). The results revealed that SOM clustering effectively distinguished composting phases and organic matter transformation trends, while network analysis identified key microbial modules (M5, M6) linked to Cu/Zn passivation. Moreover, 12% BC accelerated compost maturation, maximizing humic content (C1: anthropogenic; C4: terrestrial) by increasing Luteimonas abundance (241.98%) and reducing Terrisporobacter (92%). It also achieved the highest Cu (36.36%) and Zn (32.34%) passivation. Although 10% BC promoted C4 synthesis but inhibited C1 formation, it ultimately reached a similar maturity level to 12% BC. Additionally, 10% BC demonstrated comparable Cu (34.85%) and Zn (27.89%) passivation, making it a more cost-effective alternative. These findings highlight SOM as a robust tool for compost evaluation, optimizing BC application and improving composting efficiency.

Source: Agronomy

DOI: 10.3390/agronomy15040778

Authors: Hongqiong Zhang, Xinlong Yu, Lina Luo, Yong Sun, Ling Zhou, Haimei Fu

Institutions: Northeast Agricultural University, Tarim University, Xinjiang Uygur Autonomous Region Education Department, Beijing Academy of Science and Technology

Language: English

Topic: Composting and Vermicomposting Techniques

Subfield: Soil Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDGs: Responsible consumption and production, Zero hunger

Open Access status: gold

Estimated APC paid: $3,137