Figures (5)  Tables (3)
    • Figure 1. 

      Effects of fertilization Poa pratensis L. cv. Qinghai seed Yield. Different lowercase letters represent significant differences at the 0.05 level.

    • Figure 2. 

      Effects of different fertilization treatments on Poa pratensis L. cv. Qinghai seed quality.

    • Figure 3. 

      Effects of different fertilization levels on seed quality of Poa pratensis L. cv. Qinghai.

    • Figure 4. 

      (a) Three-dimensional curved surface diagram of the change in Poa pratensis L. cv. Qinghai seed yield under the interaction of N and P fertilizers. (b) Isogram of Poa pratensis L. cv. Qinghai seed yield under the interaction of N and P fertilizers.

    • Figure 5. 

      Intermonthly changes in (a) temperature, (b) humidity, (c) solar radiation, and (d) precipitation in the Maying area from July 2021 to August 2022.

    • TreatmentPanicle length /cmSpikelets numberSeeds number
      /per panicle
      Floret site utilizationThousand-seed-weight /gReproductive branch
      number per square meter
      N0P0K011.55 ± 0.6abc16.67 ± 1.76a91.33 ± 1.33d0.89 ± 0.03a0.21 ± 0.01e2376.73 ± 18.01d
      N0P2K213.64 ± 0.81ab20.67 ± 2.19a106.67 ± 0.33c0.78 ± 0.03c0.29 ± 0.01abc2794.13 ± 57.27c
      N1P2K212.27 ± 0.13abc16.00 ± 0.58a121.33 ± 6.84b0.85 ± 0.11b0.23 ± 0.01de3189.67 ± 122.00b
      N2P0K211.58 ± 1.58abc17.67 ± 1.20a128.00 ± 1.53ab0.91 ± 0.01a0.28 ± 0.01bc3353.89 ± 35.22ab
      N2P1K211.78 ± 0.26abc20.67 ± 4.81a131.33 ± 5.04ab0.90 ± 0.03a0.26 ± 0.02cd3444.86 ± 198.35ab
      N2P2K213.29 ± 0.61ab18.67 ± 0.88a134.00 ± 4.73a0.90 ± 0.05a0.23 ± 0.01e3528.68 ± 125.73a
      N2P3K211.05 ± 1.17abc18.67 ± 2.40a127.33 ± 1.86ab0.85 ± 0.03b0.31 ± 0.01ab3327.71 ± 34.95ab
      N2P2K011.2 ± 0.97abc19.67 ± 3.71a123.00 ± 2.52ab0.91 ± 0.03a0.22 ± 0.02e3201.11 ± 53.94b
      N2P2K111.58 ± 0.16abc18.67 ± 2.19a124.33 ± 3.38ab0.86 ± 0.09ab0.27 ± 0.01cd3249.9 ± 25.04b
      N2P2K313.01 ± 1.12ab18.00 ± 1.15a127.67 ± 3.18ab0.88 ± 0.03ab0.23 ± 0.02de3345.80 ± 28.44ab
      N3P2K212.73 ± 1.24abc18.00 ± 2.08a125.33 ± 0.88ab0.87 ± 0.03ab0.31 ± 0.01ab3271.64 ± 57.50ab
      N1P1K213.83 ± 0.74a18.33 ± 2.40a121.67 ± 3.28b0.78 ± 0.03c0.26 ± 0.01cd3181.97 ± 24.36b
      N1P2K110.82 ± 0.36bc15.33 ± 1.76a127.00 ± 2.08ab0.80 ± 0.09bc0.21 ± 0.01e3339.12 ± 33.80ab
      N2P1K19.95 ± 0.92c16.00 ± 1.00a125.00 ± 2.89ab0.88 ± 0.03ab0.32 ± 0.01a3278.06 ± 36.58ab

      Table 1. 

      Effects of fertilization on seed yield components of Poa pratensis L. cv. Qinghai.

    • KMO test and Bartlett test
      KMO value0.746
      Bartlett sphericity testApproximate χ282.566
      df6
      P0.000***

      Table 2. 

      Factor analysis test of seed quality.

    • NumberingTreatmentN/kg·hm−2P2O5/kg·hm−2K2O/kg·hm−2
      1N0P0K0000
      2N0P2K2010060
      3N1P2K26510060
      4N2P0K2130060
      5N2P1K21305060
      6N2P2K213010060
      7N2P3K213015060
      8N2P2K01301000
      9N2P2K113010030
      10N2P2K313010090
      11N3P2K219510060
      12N1P1K2655060
      13N1P2K16510030
      14N2P1K11305030
      Note: The number of subscripts in the second column is the code of each factor.

      Table 3. 

      N, P, K ratio treatment and fertilizer application amount.