Molecular Soil Biology 2025, Vol.16, No.1, 1-15 http://bioscipublisher.com/index.php/msb 6 reducing nitrogen losses (e.g., lowering N2O emissions and NO3- leaching). Through appropriate nitrogen application rates and the use of EEFs, effective nitrogen management can balance vegetative and tuber growth, ensuring high yields and high-quality tubers (Pan et al., 2023). Figure 2 Effects of Enhanced Efficiency Fertilizer (EEF) on Potato Yield Increase and Nitrogen (N) Loss Reduction (Adapted from Pan et al., 2023) Image caption: Demonstrates that enhanced-efficiency fertilizers, especially polymer-coated urea (PCU), significantly improve potato productivity metrics (yield, N uptake, NUE) while effectively reducing nitrogen losses through decreased N2O emissions, nitrate leaching, and ammonia volatilization. Different types of EEFs vary in effectiveness, highlighting the importance of selecting the appropriate formulation based on specific environmental and productivity goals (Adapted from Pan et al., 2023) 4.2 Nitrogen Application Timing and Split-Dose Strategies The timing of nitrogen application is critical to maximizing nitrogen use efficiency (NUE) and minimizing nitrogen losses through leaching or volatilization. Splitting nitrogen applications into multiple doses throughout the growing season is an effective strategy to ensure that nitrogen is available to the plant when it is most needed. Typically, nitrogen is applied at planting, followed by additional applications at key growth stages such as emergence and tuber initiation. This approach ensures that nitrogen is available during the plant’s most active growth periods, reducing the risk of nitrogen being lost before the plant can absorb it (Rens et al., 2018). Research has demonstrated that split-dose strategies significantly improve both yield and tuber quality. For example, applying a portion of nitrogen at planting, followed by additional applications during the crop’s critical growth stages, has been shown to optimize nitrogen uptake and tuber formation. In studies conducted in Florida, split nitrogen applications at planting, emergence, and tuber initiation resulted in higher yields compared to a single nitrogen application. Moreover, delaying too much nitrogen application until later stages, such as tuber initiation, can reduce the plant’s ability to utilize nitrogen efficiently, leading to nitrogen losses and suboptimal yields (Rens et al., 2016). Slow-release nitrogen fertilizers are another tool to improve nitrogen timing. These fertilizers gradually release nitrogen into the soil over time, providing a more consistent nitrogen supply throughout the growing season. This can reduce the need for multiple applications while minimizing nitrogen losses due to leaching or volatilization. By synchronizing nitrogen release with crop demand, slow-release fertilizers help increase nitrogen use efficiency and improve tuber yield and quality (Shrestha et al., 2023). 4.3 Risks of over-fertilization, nitrogen leaching, and environmental concerns Over-fertilization with nitrogen poses significant environmental risks, particularly in regions where potatoes are grown on sandy soils that are prone to leaching. When nitrogen is applied in excess of crop requirements, it is
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