Genomics and Applied Biology 2026, Vol.17, No.1, 26-36 http://bioscipublisher.com/index.php/gab 27 will be retained, all of these are related to this height. The mechanized operation procedures require that the ridge height be uniform and not less than 25 cm. This is not just a formal requirement; if the ridge is too short, the root activity layer is restricted, and it is more prone to oxygen deficiency after rain, and the stability of machine operation is also poor. The root zone gas environment cannot be ignored either. Studies have found that when the CO₂ level in the root domain increases, the net photosynthetic rate of the leaves and the stomatal conductance will both decrease (Bhattarai et al., 2017); while through ventilation within the ridge, reducing the CO₂ level from 0.5%-1.4% to 0.1%-0.2%, the fresh and dry weight of the root tubers can reach approximately 1.18-1.19 times that of the control (Jin et al., 2020). This indicates that the underground ventilation condition will, in turn, affect the carbon assimilation in the aboveground part and the yield of root tubers. Rather than considering ridge formation as an external form, it is through the interaction of oxygen, CO₂ and water that it influences the source-sink relationship and the efficiency of root tuber expansion. First, starting from the soil structure, moisture and temperature changes, let's examine how the ridge height affects the formation and subsequent expansion of tubers. Second, based on the existing experimental results and production procedures, summarize the common patterns of yield composition, commercial potato rate, and the occurrence of abnormal and cracked tubers under different ridge height conditions. Third, taking typical ecological areas such as the southeastern paddy soil region as examples, propose feasible ridge height ranges and corresponding management strategies for actual production. The overall approach is not to simply draw conclusions but to follow a "chain of evidence": first, extract the applicable ridge height ranges from the standards and technical opinions, such as 30-35 cm for clay soil, 25-30 cm for sandy loam soil, and a ridge height of no less than 25 cm, etc. Then, use field experiments to verify the advantages of moderate ridge height in terms of yield and mechanical harvesting. Finally, use physiological and ecological research to explain the internal reasons such as improved aeration, energy supply, and the transport of assimilates to the tubers. 2 The Regulatory Mechanism of Ridge Height on Growth Environment 2.1 Effects of different ridge heights on soil physical properties (aeration, looseness) Raising ridges ultimately means rebuilding the original cultivation layer. The ridge has been raised, and the loose soil layer is often thicker, making the drainage channels of the ridge clearer. Especially in heavy soil, this change is particularly crucial - water cannot be drained out, air cannot enter, and the problem is concentrated here (Colombi et al., 2018). So in the technical opinion, the height of the clay ridge is set at 30-35 cm, while the height of the sandy loam soil is lowered to 25-30 cm. There are actually two orientations behind this: the clay should be raised to promote drainage, while the light sandy soil should prevent rapid water loss. The local mechanization regulations also specify the indicators more specifically, with requirements ranging from 20-40 cm for different ridge types, and emphasize that operations are more ideal when the moisture content of cultivated land is between 20% and 40%. In other words, if the ridge cannot be broken, loosened, or leveled, it will directly affect the ventilation status and the resistance of the root system. From a physiological perspective, after improved ventilation, ATP metabolism in leaves and tubers becomes more active, and assimilates are transported more smoothly to tubers (Nunes et al., 2016). This is precisely the intrinsic reason why sweet potatoes prefer looseness and fear compaction. Therefore, instead of staring at the height of the ridge in centimeters, it is better to focus on whether a truly “breathing” ridge can be formed in the target soil. 2.2 The impact of ridge height on soil moisture and temperature dynamics Once the ridge is raised, the water distribution in the field often becomes uneven, forming a state where the soil is wetter in the ditches and drier on the ridges. During rainfall, water tends to flow into the ditches and be drained away, which is beneficial for alleviating waterlogging. However, in areas with water shortage or severe drought, this structure may also cause the ridges to lose moisture more quickly. The mechanized operation procedures repeatedly emphasize that the ridge height and shape should be consistent, which is actually to stabilize this moisture pattern and avoid the situation where "some areas have good moisture while others are relatively dry" on the same piece of land during the expansion period, thereby widening the variation in tuber shape (Li et al., 2019). Besides moisture, the soil temperature also changes.
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