Beyond synthetic fertilizers: Recycled organic residuals deliver balanced nutrition and sustained corn yield

Recycling organic wastes into fertilizing residual materials (FRMs) offers a powerful strategy to replace synthetic fertilizers, reduce environmental impacts, and promote circular agriculture. Yet, their agronomic value in cool-climate regions such as Eastern Canada remains underexplored, particularly regarding nutrient balance. The main objective of this study is to evaluate the agronomic performance of eight recycled FRMs derived from composts, digestates, sludges, and ashes applied in combination with mineral fertilizers on silage and grain corn across two contrasting soil textures over two seasons. A study was conducted on two experimental sites where FRMs substituted either one-third of the nitrogen or the total phosphorus requirements. Corn yield was measured on the central rows of each plot. The nutritional status of grain corn was assessed with the Compositional nutrient diagnosis (CND) at the silking stage. At the end of the experiment, soil samples (0–10 cm) were taken and analyzed for chemical properties. Results showed that all FRM treatments matched the yield of full mineral fertilization (10.55 Mg ha⁻¹ and 11.18 Mg ha⁻¹ on clay and loam soils, respectively). On the well-drained loam site, every FRM supported balanced crop nutrition, with composts and deinking paper sludge outperforming the mineral-only treatment. On the poorly drained clay soil, almost all treatments, even the mineral treatment, produced unbalanced grain corn. Only the digestates provided balanced nutrition, showcasing their superior mineralization potential. These findings demonstrate that FRMs can effectively replace synthetic fertilizers without compromising yield or crop health. By transforming organic waste into high-value agronomic inputs, this approach enhances sustainability, cuts production costs, and strengthens the resilience of farming systems. • Recycled residuals match or exceed the performance of mineral fertilizers in terms of corn yield. • Organic waste products improved crop nutrient balance on well-drained soils. • Digestates provide balanced nutrition even in heavier-textured soils. • Circular fertilization lowers production costs and enhances agroecosystem sustainability. • Field evidence supports replacing synthetic P or N with biowaste-derived fertilizers.