Abstract: In order to explore the migration and accumulation of nitrogen fertilizer in the culture substrate of the greenhouse, and its absorption and distribution characteristics in various organs of pepper plants. Pepper (variety:Longjiao No.10) was used as the test material, and K¹⁵NO₃ was used to mark K¹⁵NO₃ in the depth of 5-10 cm and 15-20 cm, and set the lower limit of 60% (W60) and 80% (W80). The biomass of pepper grown in the greenhouse and the absorption and distribution of nitrogen in various organs of pepper and the migration of nitrogen in the culture substrate were studied. The results showed that the 60% minimum irrigation limit significantly increased the total biomass and nitrogen uptake of pepper plants. In the spatial distribution, the deeper the ¹⁵N mark fertilization depth, the lower the utilization rate of the pepper plant to ¹⁵N. In spatial distribution, the deeper the ¹⁵N labeled fertilization depth, the lower the ¹⁵N utilization rate of pepper plants. Meanwhile, the accumulation of ¹⁵N in the basal layer (0-20 cm) also decreased significantly, increased the amount of loss significantly. Under 60% irrigation water limit, the loss of ¹⁵N in the matrix was less than that under 80% irrigation condition. At this point, the amount of ¹⁵N migration downward at 15-20 cm of the matrix layer was reduced, and the absorption and utilization of total nitrogen by various organs of pepper plants under the condition of 60% lower irrigation limit was increased. Therefore, W60F5 treatment could increase the total biomass and nitrogen uptake of pepper plants, and reduced the downward nitrogen transport of the matrix, which was beneficial to the better absorption and utilization of pepper plants. The bioaccumulation and nitrogen uptake of various organs of pepper plants were leaf > fruit > stem.

Key words: Pepper, ¹⁵N isotope tracing technique, Nitrogen distribution, Substrate migration

CLC Number: 

• S143.1