Abstract: In order to ensure the commercial quality of Lanzhou edible lily bulbs under the conditions of dryland,it is necessary to scientifically determine the planting density.In this experiment,the growth analysis method was used to study the effects of two planting densities on the dry matter and nutrient uptake of lily bulbs.The result shows that the planting density significantly affects the dynamics of dry matter and NPK absorption and accumulation during the growth period of different growth years.The increase of density can improve the accumulation rate of dry matter in underground plants and bulbs at the seedling stage and bud stage,and while the accumulation of dry matter increases,the time of rapid accumulation of dry matter is shortened,and the peak of dry matter accumulation is advanced.The absorption and accumulation of nitrogen,phosphorus and potassium nutrients per unit area of Lanzhou edible lily bulbs improved with the increase of planting density.Compared with the low density,the difference of dry matter,phosphorus and potassium accumulation in the first year of wilting （192 d） was extremely significant （P<0.01）,while the difference in nitrogen accumulation was not significant （P>0.05）.There was no significant difference in the accumulation of dry matter and nitrogen,phosphorus and potassium in the second year of the wilt period （533 d）（P>0.05）.In the second year of the wilt period,compared with the first year,the cumulative growth of NPK in the low-density planting bulbs was higher than that in the high-density planting.The accumulation of nitrogen,phosphorus and potassium in the bulbs increased by 79.11%,72.48%,and 21.45% at low density,respectively,and increased by 48.34%,11.56% and -20.09% at high density,respectively.The reasonable planting density of Lanzhou edible lily bulbs is 600 000 plants/hm² to 650 000 plants/hm².

Key words: Lanzhou lily, Density, Dry land, Dry matter, Nutrient uptake accumulation, Bulb