Abstract:

In order to explore the effects of cultivation density and nitrogen fertilizer application on potato yield and quality in high-altitude areas, a two factor split plot experimental design was adopted. Three density levels (41700, 50000, 62500 plant/hm², represented as D₁, D₂, D₃ respectively) and four nitrogen application levels (0, 110, 220, 330 kg/hm², represented as N₀, N₁, N₂, and N₃ respectively) were set up to analyze different densities and the effect of nitrogen fertilizer treatment combination on the plant traits, yield, and quality of the late maturing potato variety ‘Zangnongshu 1’, and explore the optimal fertilizer density configuration for this variety. The results showed that density and nitrogen fertilizer had a significant impact on the traits, yield, and quality of potato plants, and the yield and quality were significantly affected by the interaction between density and nitrogen fertilizer. The potato yield and commercial potato yield under low density of 41700 plants/hm² increased with the increase of nitrogen application. The dry matter content, starch content, and protein content showed a trend of first increasing and then decreasing with the increase of nitrogen application. The potato yield and commercial potato yield under high density of 50000 plants and high density of 62500 plants/hm² increased and then decreased with the increase of nitrogen application, while the dry matter content, starch content, and protein content showed an upward trend. The highest potato yield under D₂N₂ treatment was 47884 kg/hm², with a commercial potato yield of 56.03%, and good performance in plant and quality traits. Taking into account plant, yield, and quality traits, based on TOPSIS analysis results, it is more suitable to plant potatoes in Lhasa and its surrounding areas with a density of 50000 plants/hm² and a nitrogen application rate of 220 kg/hm².

Key words: potato, density, nitrogen fertilizer, yield, quality, high-altitude areas, Lhasa