Effect of Altered Nitrogen Distribution on Corn Grain Yield (N Distribution)

Objectives: 

1. To determine the application resolution at which N competition influences corn grain yield.
2.  To determine the N application resolution at which corn grain yields are maximized.

9-Plant Sequences, 3-row plots

Plant population, 30” rows, 6” spacing (34848 plants/ac) and 10” spacing (20942 plants/ac)

Preplant N rate:    40 lb N/ac

Topdress N rate:  55 lb N/ac dryland or 110 lb N/ac irrigated

Row Spacing: 30 inches

Area per plant:  6” distance = 1.25 ft², 10” distance = 2.08ft²

Variables to be measured:

NDVI at V8 and V12
Grain yield, by plant from all treatments and set

Effect of Delayed Emergence on Corn Grain Yields (Delayed Emergence)

Objectives: 

1. To determine corn grain yield reduction as a function of delayed plant emergence, simulated by delayed planting.
2.  To determine yield levels associated with 3 plant sequences, with and without delayed emergence.
3.  To determine if v8-v12 NDVI readings can be used to detect single plants that are behind.

3 Plant Sequences, 3, 3 continuous sets.

            Delay in Planting                                                       N rate, lb/ac

1.         All 3 plants planted on the same day                      50
2.         Middle plant planted 2 days late                              50       
3.         Middle plant planted 4 days late                              50
4.         Middle plant planted 6 days late                              50
5.         Middle plant planted 8 days late                              50
6.         All 3 plants planted on the same day                      150
7.         Middle plant planted 2 days late                              150    
8.         Middle plant planted 4 days late                              150
9.         Middle plant planted 6 days late                              150
10.       Middle plant planted 8 days late                              150 

Variables to be measured:

NDVI at V8 and V12
Grain yield, by plant from all treatments and sets

Example (treatment 2), Border rows left and right, all plants planted on the same day.