Nitrogen fertilizer is an important kinetic energy for potato production. To study the effect of nitrogen(N) fertilizer application and the topdressing ratio on potato growth and yield, different N application levels: N75 (75 kg ha−1), N150 (150 kg ha−1), N225 (225 kg ha−1) and different N fertilizer base/topdressing ratios: T1 (2:8), T2 (5:5), T3 (8:2), and T4 (10:0) were used to find the best N fertilizer operation. The results showed that higher yields can be obtained when 120–180 kg ha−1 N was applied under the base/topdressing ratio of 8:2 in silt loam (sand–silt–clay: 29-50-21). The base N fertilizer dosage largely determined the root morphology, while topdressing fertilizer mainly affected the leaf photosystem, however, rhizosphere topdressing at the early stages of bud emergence did not immediately affect the leaf soluble protein and the sugar content. Topdressing N increased the tuber crude protein and ascorbic acid content to some extent, but had weak effect on the amylose/amylopectin ratio, for the starch content was mainly influenced by total N application. When base N fertilizer was low, it could be compensated by applying fertilizer during flowering, though when the amount of base fertilizer was sufficient, topdressing would cause a decrease in the average single potato weight and an increase in potato sets per plant, thereby reducing the commercial potato rate. Overall, adopting a suitable base/topdressing ratio can promote plant growth and improve tuber quality and yield. However, the relationship between the specific application amount and the ratio under different soil texture conditions needs further study.

中文翻译：

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氮肥用量和基追比对马铃薯生长特性和产量的影响

氮肥是马铃薯生产的重要动能。为了研究氮肥施用和追肥比例对马铃薯生长和产量的影响，不同的施氮水平：N75（75 kg ha−1）、N150（150 kg ha−1）、N225（225 kg ha− 1）和不同的氮肥基追比：T1（2：8）、T2（5：5）、T3（8：2）和T4（10：0）用于寻找最佳氮肥操作。结果表明，在粉砂壤土（砂-粉-粘土：29-50-21）基追比为8:2的条件下，施用120-180 kg ha-1 N可获得较高的产量。基施氮肥用量在很大程度上决定了根系形态，而追肥主要影响叶片光系统，但是，出芽初期根际追肥对叶片可溶性蛋白和含糖量没有立即影响。追施N在一定程度上提高了块茎粗蛋白和抗坏血酸含量，但对直链淀粉/支链淀粉比影响较弱，因为淀粉含量主要受全氮施用的影响。基肥偏低时可通过施花期肥进行补偿，但基肥充足时追施可使马铃薯平均单重降低，单株结薯数增加，从而降低商业马铃薯率。总体而言，采用合适的基追比可以促进植株生长，提高块茎品质和产量。然而，