Preliminary Evaluation of Bioactive Nutrients from Steam-Exploded Quercus mongolica Wood for Crop Quality Enhancement and Agronomic Applicability

The transition toward sustainable agriculture requires developing eco-friendly inputs that reduce dependency on chemical fertilizers. In this study, a bioactive plant-nutrient solution was developed using steam-exploded biomass of Quercus mongolica (Mongolian oak). The effects of this solution were evaluated across a range of crops. The formulation, which is rich in natural polyphenols and low-molecular-weight organics, was applied under field conditions to various fruits (watermelons, tomatoes, strawberries, Campbell Early grapes, apples, and Shine Muscat grapes), and rice. This treatment resulted in significant improvement in crop quality and yield-related traits. In fruit crops, the proportion of fruits with a high sugar content increased, indicating enhanced carbohydrate accumulation. In rice, both the total polyphenol content and grain weight increased by approximately 37% and 10.5%, respectively, compared with the control. Microscopic analysis revealed an improved endosperm structure with a greater abundance of compound starch granules, suggesting better storage and textural properties. These effects were likely influenced by the antioxidant compounds present in the oak-derived formulation, which stimulated secondary metabolism and physiological robustness in plants. Our results demonstrate that the wood biomass-derived nutrient formulation tested herein can serve not only as an effective compound biostimulant but, additionally, as a practical input to promote functional food production. This novel approach offers a sustainable and resource-circular alternative to fertilization practice prevalent in conventional agriculture, thus supporting the valorization of forestry by-products while enhancing crop value and ecological compatibility.