Efficient Nitrogen Fertilization for Cultivated Wildrice Varieties
Study author(s): Dan Braaten, Dr. Albert Sims, Dr. Vincent Fritz, University of Minnesota
Years of study: 2013
Location(s): Aitkin, MN and Clearbrook, MN
Important: for the complete report, including all tables and figures, please download using the links to the right.
Summary
Trials for the 2015 season proved to be difficult to conduct. Lack of water in the spring resulted in late flooding for the trial at Clearbrook on a second year wildrice stand to be late flooded, ultimately causing the crop to fail and no useable yield data to be collected. Also, in the second year wildrice stand at the Aitkin location, a lack of a useable stand also was a problem. Plant density was below the threshold of 1 plant per square foot, making yield data here as well not feasible. Data collected for yield on the nitrogen strip trials was restricted to just those fields coming out of a legume crop at both the Aitkin and Clearbrook site. The Clearbrook site had yields significantly lower due to disease issue and week later than usual harvest due to we conditions in the field not allow the harvest equipment through the field. Data for that is shown in graphic below. This again help with clarifying the original objectives 1 and 2.
No data was again collected this growing season for objective 3, looking at varietal response to ESN. Low plant densities, and the presence of volunteer plants floating in for the grower fields, made it impossible to conclude what was a plot and what wasn’t. This uncontrollable variability and issues with this type of on-farm research (having to put varietal yield plots within a broadcast seeded growers paddy) made this objective unachievable.
The research has focused on more efficient use of nitrogen – and not losing it to denitrification – in wild rice. When wild rice is flooded, nitrogen is applied aerially, which has shown to be less efficient. In order to mitigate some of this inefficiency, the team looked at environmentally smart nitrogen, or ESN, which is a product made by Agrium. The thought was that with ESN – the polymer coated urea – nitrogen would release slowly and then growers could maybe put more it on early in the fall, and then it would last through one top dress timing, so we would be able to eliminate that.