The Effects of Topdressing Organic Nitrogen on Hard Red Winter Wheat Yield and Quality: Part II

The Effects of Topdressing Organic Nitrogen on Hard Red Winter Wheat Yield and Quality: Part II

Summary

The demand for local organic food is steadily increasing throughout Vermont and New England. Consumers are asking for bread baked with locally grown wheat; however bakers have been slow to incorporate local wheat flour because of the challenges associated with obtaining grains that consistently meet bread-baking standards. Addressing the quality issue is essential for expanding the bread flour market in the northeast.

One of the major quality factors facing Vermont grain producers is protein content. Much of the wheat currently produced in Vermont has protein levels below what most commercial mills would consider suitable for flour production. Assuring adequate available nitrogen (N) for grain yield and protein are the primary challenges of organic winter wheat production in New England. Topdressing N to increase protein quantity and quality is recommended for conventionally grown wheat, but the effectiveness of topdressing organic N sources needs evaluation.

In 2011, we were awarded a partnership grant titled “The Effects of Topdressing Organic Nitrogen of Hard Red Winter Wheat Quality and Protein Part II”, to continue to explore the relationship between topdressing organic nitrogen amendments (composted poultry manure, Chilean nitrate, and Pro-Booster, an available bagged fertilizer), the application times (tillering, flag leaf, and split application at both times), and how these two factors influence the quality and quantity of grain protein, on farm. First year results demonstrated that topdressing can have a positive impact on both yield and quality. However, one year of data is not adequate to confidently recommend that farmers begin changing fertility practices. Therefore our group repeated the study in 2011 to verify our 2010 results.

In 2011, the topdressing of wheat at tillering and flag leaf stage did not increase yields compared to the unamended control. However, crude protein (CP) differed significantly among treatments. Organic nitrogen treatments including Probooster and Chilean nitrate applied at the flag leaf stage resulted in higher CP concentrations than Cheep Cheep applied at flag leaf stage. The control did not differ significantly from that amended treatments. Above average precipitation during the growing season may have resulted in significant N leaching from all treatments.

Objectives/Performance Targets

The objective of this project is to determine if topdressing wheat with organic N sources during critical uptake periods will improve overall yield and quality. In collaboration with our co-operating farmer, we evaluated the impact of three different organic N sources; composted chicken manure, Chilean nitrate, and Pro-Booster, applied at two different times during the growing season; spring application, application at flag leaf, and a combination of the two on wheat yield and quality.

Accomplishments/Milestones

• In April 19 of 2011 the trial plots at Gleason Grains in Bridport, VT were established.
• Amendments were applied at key developmental stages (tillering and flag leaf).
• Plant biomass and soil nitrate samples were taken throughout plant development and are in the process of being analyzed.
• On July 20, 2011 the plots were harvested and grain yields calculated.
• Fall of 2011, gain quality testing; % grain moisture, test weight, crude protein, falling number and DON analysis, were conducted on the grain from each of the test plots at the University of Vermont’s Cereal Testing Laboratory in Burlington, VT. Plant biomass samples were sent to Cumberland Valley Analytical Laboratory.
• On June 9, 2011 a workshop was held at Gleason Grains in Bridport, VT which highlight the N topdressing trial. There were 40 people in attendance.
• On June 21, 2011 a workshop was held at Aurora Farms in Charlotte, VT. The Kenyon family discussed their interest in large scale organic N topdress trials at their farm. There were 50 people in attendance.
• October 7, 2011 an episode of “Across the Fence” aired highlighting the project; http://www.youtube.com/watch?v=dJy5jmG6_lw&list=UUr8rzEUNSC2s5VNWfEZ3Qaw&index=13&feature=plcp
• In January of 2011 a research report was written; hard copies will be handed out at winter conferences and workshops and a pdf version will be posted on both the UVM Extension NorthWest Crops and Soils Team and Northern Grain Growers Association (NGGA) websites.

• Summary of Research Results

Impacts and Contributions/Outcomes

These second year results demonstrated that topdressing can have an impact on wheat protein concentrations. However, due to weather conditions in 2011 it is difficult to determine if there were any significant impacts on yield. Farms are interested in implementing topdressing as a practice to improve wheat yield and quality. However, the data is still relatively inconclusive. The largest organic wheat producer in the state, located in Charlotte, Vermont, attempted to conduct a larger scale organic nitrogen topdressing trial during the 2011 growing season on some of their winter wheat fields as a result of our 2010 findings. Unfortunately due to the heavy rains and their dense clay soils the fields didn’t dry out in time to topdress the wheat. However they plan to try again in the 2012 growing season

Collaborators: