Figures (4)  Tables (7)

    • Figure 1. 

      Comparison of the empirically observed and model-simulated dry matter employing the APSIM framework for the SC704 hybrid cultivar, subjected to varying nitrogen levels (0, 92, and 368 kg·ha−1), was conducted in the years 2020 (a) calibration and 2021 (b) validation.

    • Figure 2. 

      A comparative analysis of the actual and predicted grain yield utilizing the APSIM model for the SC704 hybrid was conducted under varying nitrogen applications (0, 92, and 368 kg·ha−1) during the year 2020, designated as the calibration year.

    • Figure 3. 

      A comparative analysis of the empirically observed and model-predicted grain yield of the SC704 hybrid was conducted utilizing two distinct datasets[14,15] under varying nitrogen applications (0, 92, and 368 kg·ha−1) in the year 2021 (validation) within the Kerman region.

    • Figure 4. 

      Grain productivity in relation to various irrigation regimens (IR11: 11 irrigation instances; IR13: 13 irrigation instances; IR15: 15 irrigation instances), planting periods (early, common, and late), as well as the geographical sites examined (Bardsir, Jiroft, and Orzueeyeh). The dimensions of the box plots illustrate the variations in the projected grain yield across different years (2000−2019).

    • Region Longitude Latitude Elevation (m) Mean annual temperature (°C) Mean cumulative precipitation (mm)
      Bardsir 56.57 29.93 2044 14.5 165
      Orzueeyeh 56.36 28.45 1053 23.3 122.3
      Jiroft 57.73 28.67 720 25.1 176.2

      Table 1. 

      Climatic and geomorphological attributes of the regions.

    • Attributes Region
      Bardsir Orzueeyeh Jiroft
      Soil type Loam sand Loam Loam sand
      Available soil water (mm) 126 113 115
      Bulk density (g·cm−3) 1.4 1.62 1.52
      pH 7.9 7.9 8
      Electrical conductivity (dS·m−1) 2 1.9 1.2
      Organic matter (%) 0.2 0.2 0.2
      Nitrate (mg·L−1) 8.2 79.4 73.1
      Ammonium (mg·L−1) 2.13 2.26 2.76
      Phosphorous (ppm) 4 4 10
      Potassium (ppm) 120 180 200

      Table 2. 

      Pedological attributes of the regions.

    • Location Sowing window Number of
      irrigations      		 Nitrogen fertilizer
      (kg N ha−1)
      Bardsir 21-Apr 16 276
      Orzueeyeh 01-Jul 16 260
      Jiroft 21-Jul 16 253

      Table 3. 

      Common sowing window, number of irrigations, and the quantity of nitrogen fertilizer.

    • Parameter Value Unit
      Maximum number of seeds per head 850 −
      Thermal time from emergence to juvenile stage 270 °Cd
      Seed growth rate 8 mg kernel–1 d–1
      Thermal time from juvenile phase to floral stage 20 °Cd
      Critical photoperiod 1 12.5 h
      Critical photoperiod 2 20 h

      Table 4. 

      Parameters determined by adjusting the model calibration for SC704 cultivar.

    • Treatment Calibration (2020) Validation (2021)
      Observed Simulated Observed Simulated
      Days from sowing to flowering
      0 kg N ha−1 74 69 87 66
      92 kg N ha−1 68 69 80 66
      368 kg N ha−1 69 69 76 66
      nRMSE (%) 2.41 10.17
      CRM (−) 0.018 0.185
      Days from sowing to maturity
      0 kg N ha−1 131 129 135 123
      92 kg N ha−1 128 129 134 123
      368 kg N ha−1 132 129 136 123
      nRMSE (%) 0.95 5.14
      CRM (−) 0.01 0.08

      Table 5. 

      Evaluation indices of the APSIM model in simulating days from sowing to flowering and maturity under different nitrogen fertilizer (0, 92, and 368 kg·ha−1) in calibration (2020), and validation (2021) years.

    • TotalCalibration (2020)Validation (2021)
      nRMSE (%)CRM (−)nRMSE (%)CRM (−)
      Dry matter13.770.1912.75−0.18
      Grain yield11.230.1213.21−0.15

      Table 6. 

      Evaluation parameters of model in simulating total dry matter and grain yield of maize SC704 hybrid under the different quantity of nitrogen (0, 92, and 368 kg·ha−1) for calibration (2020), and validation (2021) years.

    • Region Planting window Average temperature during the growing season (°C) Days to maturity Average maximum temperature for flowering period (°C)
      Bardsir Common 22.3 142 34.5
      Early 22.5 154 33.9
      Late 20.7 141 33.9
      Orzueeyeh Common 28.7 133 38.9
      Early 32.6 129 42.3
      Late 22.5 154 34.4
      Jiroft Common 28.2 130 38.7
      Early 31.8 124 41.3
      Late 21.4 154 33.9

      Table 7. 

      Average temperature for growing season, days to maturity, and average maximum temperature for flowering period under different planting windows (common, early, and late) and regions (2000−2019).