Regional Investigation on Interaction of Nitrogen Management, Hybrid Selection, and Population on Corn Production

IPNI-2011-GBL-47

21 Dec 2011

Project Description


A large number of studies within individual states have investigated the effects of plant populations and their interactions with corn hybrids. Recently, numerous studies have investigated the use of ground-based active optical sensors for use in predicting corn N requirement. The results of the sensor studies have been mixed, perhaps due to differences in corn hybrid selection or due to environmental effects.


Methodology

These experiments will be conducted using the same protocol in each state. The coordinating institution will be the University of Nebraska, headed by Dr. Richard Ferguson at UNL, Lincoln. This will be the institution housing the graduate student assigned to the project. The other collaborators and co-PI’s will be Dr. Newell Kitchen at University of Missouri/USDA-ARS, Columbia, and Dr. Dave Franzen at North Dakota State University. The protocol for the experiment is as follows:

There will be two experiments in each state. One site will be on a highly productive soil environment with a history of high corn yield. The other site will be on a soil with lower corn yield potential due to a soil restriction such as texture, drainage or shallow rooting depth. The two sites will be located as close to each other as possible, to minimize the weather X treatment interactions. Within each site an experiment will be established using a split-split plot design. Main treatments will be 2 populations, sub-treatments will be 2 corn hybrid types, and sub-sub treatments will be 2 in-season N management strategies. There will be 4 replications of each series of treatments in a randomized complete block design. Each experimental unit will be 30 feet long and at least 6 rows wide.

The population treatments will be the ‘standard’ population for the variety recommended by the seed company and the ‘enhanced’ populations will be 5,000 seeds/acre higher planting rate. The corn hybrids will be a ‘race-horse’ hybrid, so-called because of its history of high performance if fertilizer inputs are high, and a ‘work-horse’ hybrid, so-called because of its ability to perform well under periods of stress or under normal soil fertility environments. The N management strategies will all be imposed after a modest preplant rate of N is applied, probably around 60 lb N/acre, followed by (1) a side-dress application of N using the rate from the Maize-N management decision model (2) by a side-dress N application made using a ground-based active optical sensor algorithm.


Objectives
  1. To determine the utility of active optical ground-based sensors over a 3-state region, including sites in Missouri, Nebraska and North Dakota in predicting N need and enhancing corn yield.
  2. To determine the effect of plant population on the effectiveness of in-season N-rate prediction and application.
  3. To determine the effect of using a ‘race-horse’ hybrid vs a ‘work-horse’ hybrid on in-season N-rate prediction and application.
  4. To determine the effect of using the sensor-based approach in a highly productive soil compared to a site with lower soil productivity.
  5. To investigate the interactions of the sensor approach vs traditional N management, plant population, soil productivity and hybrid type on corn yield.
  6. To compare the performance of the recently released Maize-N decision tool (Setiyono, et al., 2011) economic optimum N rate (EONR) calculations to in-season, sensor-based N management.