Table 1.
Pertinent phenology and climate information of isotopic N experiments conducted at ACRE and PPAC locations in 2013 and at ACRE in 2014.
| Location | Growth stages | Plant components harvested* | Biomass harvest date | GDD°C (15N days) | Cum GDD °C | Intr rain (mm) | Cum rain (mm) | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| LVS | STM | HSK | EAR | KRN | COB | |||||||
| ACRE 2013 | V16 | 23-Jul | 91 (6) | 807 | 34 | 248 | ||||||
| Planted | **ER1 | 23-Jul | 60 (4) | 807 | 34 | 248 | ||||||
| May 14th | R1 | 31-Jul | 36 (5) | 869 | 2 | 252 | ||||||
| R2 | 5-Aug | 51 (5) | 921 | 21 | 269 | |||||||
| R4 | 23-Aug | 48 (4) | 1109 | 1 | 294 | |||||||
| R5 | 14-Sep | 63 (5) | 1378 | 24 | 332 | |||||||
| PPAC 2013 | V14 | 2-Aug | 32 (4) | 624 | 5 | 345 | ||||||
| Planted | V16 | 7-Aug | 58 (6) | 672 | 45 | 346 | ||||||
| June 5th | R1 | 12-Aug | 56 (5) | 728 | 34 | 380 | ||||||
| R2 | 16-Aug | 31 (4) | 759 | 11 | 391 | |||||||
| R4 | 17-Sep | 32 (5) | 1103 | 4 | 428 | |||||||
| R5 | 10-Oct | 44 (5) | 1271 | 66 | 556 | |||||||
| ACRE 2014 | V15 | 8-Jul | 63 (5) | 721 | 4 | 230 | ||||||
| Planted | R1 | 21-Jul | 49 (5) | 851 | 0 | 274 | ||||||
| April 25th | R2 | 5-Aug | 66 (5) | 1004 | 32 | 325 | ||||||
| R4 | 22-Aug | 66 (4) | 1141 | 13 | 380 | |||||||
| R5 | 2-Sep | 92 (6) | 1269 | 42 | 443 | |||||||
| R1R6 | 25-Sep | 727 (66) | 1535 | 318 | 592 | |||||||
Growth stages of 15N application and subsequent biomass harvesting and biomass partitioning in each stage throughout the growing season. Calendar dates of biomass harvesting (Biomass Harvest date) after 4 to 6 days of 15N application. Interval of cumulative growing degree days from 15N application to biomass harvesting (GDD°C) and number of days from 15N application to biomass harvesting in parentheses (15N days). Cumulative growing degree days from planting to biomass harvesting of each growth stage (Cum GDD°C). Interval of cumulative rainfall in millimeters from 15N application to biomass harvesting in each growth stage (Intr Rain mm). Cumulative rainfall in millimeters from planting date to biomass harvesting in each growth stage (Cum Rain mm).
LVS Leaf; STM Stem; HSK Husk; KRN Kernel; COB Cob.
EARLY R1 (ER1) represents 50% of plants were at silking when 15N was applied, and R1 represents 90% of plants were at silking when 15N was applied.
Black shaded areas represent the partitioning of plant components at each growth stage.