TITLE:
Effect of Biochar Based Organic Fertilizer on Maize Growth in Cadmium Contaminated Soil
AUTHORS:
Zhiwen Yang, Junxi Yang, Ao Li, Jiacheng Shu, Shiqi Peng, Jingyi Chen, Guangjie Liu, Xiaozhuo Zhang, Li Bao
KEYWORDS:
Biochar Based Organic Fertilizer, Corn, Cadmium, Repair, Grow
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.8,
August
18,
2026
ABSTRACT: Soil heavy metal contamination, particularly by cadmium (Cd), poses a critical threat to global food security and public health. While biochar-based organic amendments represent a promising strategy for simultaneous soil remediation and crop promotion, optimizing fertilizer formulations to balance nutrient delivery with heavy metal immobilization remains a persistent challenge. Here, we evaluate the efficacy of various fertilization regimes—comprising standard organic fertilizers and two distinct biochar-based organic formulations (I and II) across three application rates (1500, 3000, and 4500 kg∙ha−1)—on soil physicochemical properties, maize growth, and Cd sequestration. Our field experiments demonstrate that the maximum application of biochar-based organic fertilizer II (T9: 4500 kg∙ha−1) induced the most profound improvements in soil quality. Compared to the unfertilized control, T9 elevated soil pH by 0.69 units, organic matter by 43.661%, alkali-hydrolyzable nitrogen by 22.195%, and available potassium by 36.243%, ultimately culminating in a 64.078% increase in maize yield. Crucially, the 3000 kg∙ha−1 treatments of both biochar-based fertilizers (T5 and T8) achieved identical maximum grain Cd reduction of 26.271%. Among them, T8 (modified biochar-based organic fertilizer II, 3000 kg∙ha−1) showed superior soil Cd immobilization capacity, decreasing DTPA-extractable soil Cd by 32.842% and outperforming conventional organic fertilizer and unmodified biochar-based organic fertilizer I. Collectively, customized biochar-organic composites can restore degraded contaminated soil while guaranteeing agricultural product safety, which provides a feasible and expandable technical scheme for low-carbon sustainable agriculture in heavy metal-polluted farmlands. The comprehensive performance of tested fertilizers followed the order: modified biochar-based organic fertilizer II > unmodified biochar-based organic fertilizer I > conventional organic fertilizer. Notably, optimal dosages diverged for Cd remediation (3000 kg∙ha−1, T8) and grain yield promotion (4500 kg∙ha−1, T9), owing to distinct limiting factors of heavy metal immobilization and crop nutrient demand.