In a detailed study published in the journal Plants, lead author Yanghui Sui and a team of researchers investigated how the frequency of biochar application influences the physical development and internal energy processes of maize. As global agriculture faces increasing threats from extreme weather and the need for higher planting densities, finding ways to strengthen crop stems while maintaining high productivity has become a priority. The research team focused specifically on the development of internodes, the sections of the stem that provide structural support, and photosystem II, the part of the plant’s photosynthetic machinery responsible for capturing light energy. By analyzing these factors over a long-term six-year experiment, the authors provided new insights into how soil amendments can stabilize crops against physical damage like lodging, where stems break or bend under stress.

One of the most striking findings from the research is the significant physical improvement in the maize stalks. The study revealed that when biochar is applied annually in combination with conventional nitrogen fertilizer, the thickness of the critical lower internodes increases substantially. Specifically, the second through fifth nodes showed thickness gains ranging from 16 to nearly 22 percent. These lower sections of the plant are the most vulnerable to snapping, and their reinforcement is a key factor in the plant’s ability to withstand environmental pressures. Furthermore, annual application was found to be more effective than biennial application for maintaining a high stem diameter coefficient in the first three nodes. This suggests that a consistent presence of biochar in the soil provides a more stable environment for steady stem development throughout the growing season.

The benefits of biochar extend beyond mere physical strength and into the very heart of the plant’s energy production system. The researchers discovered that biochar treatments significantly modulate the photosynthetic efficiency of the leaves. During the post-flowering stage, which is vital for grain filling, the combination of biochar and nitrogen reduced the fraction of energy lost to unregulated processes by half. More importantly, it increased the actual quantum yield of photosystem II by 30 percent. This means the plants became much more efficient at turning sunlight into chemical energy rather than wasting it as heat. This enhanced photosynthetic capacity ensures that the plant has enough sugar and nutrients to invest in both a heavy ear of corn and a sturdy stalk, effectively resolving the common trade-off where high-yielding plants often have weaker stems.

The study also highlighted the importance of nutrient synergy, showing that biochar helps the plant make better use of nitrogen fertilizer. In plots where biochar was absent or nitrogen was limited, the plants were shorter and had significantly lower dry weights in their internodes. In contrast, the best performing treatments resulted in plant heights reaching over 266 centimeters and significantly higher biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More. While nitrogen alone can improve some growth traits, it often leads to tall, spindly plants that are prone to falling. Biochar acts as a balancing agent, ensuring that the increase in height is matched by a corresponding increase in stem diameter and internal structural integrity. This coordination allows for modern high-density planting without the associated risk of massive crop loss due to wind or rain damage.

Ultimately, the researchers concluded that the most effective strategy for farmers involves a specific balance of amendments. According to the yield data, applying approximately 8.4 tons of biochar every two years in conjunction with a standard nitrogen rate produced the most favorable results. This combination not only maximized the weight of the grains but also ensured the plants remained standing until harvest. The study provides a clear scientific roadmap for using biochar as a sustainable tool to enhance crop resilience. By improving both the mechanical properties of the stalk and the efficiency of the leaves, this approach offers a dual benefit that supports long-term food security and agricultural stability in an increasingly unpredictable climate.

Source: Sui, Y., Gao, J., Wang, D., Zhang, Y., Ye, Y., Xiao, W., & Wang, Y. (2026). Annual biochar application regulates maize internode development and yield by modulating photosystem II photosynthetic efficiency. Plants, 15(8), 1141.