Nitrogen mineralization has been difficult to assess. Many attempts have been made to develop indices of N mineralization, but the methodologies to do so have been elusive. These attempts have included laboratory methods of chemical extractions (Keeney, 1982) and incubation studies (Stanford and Smith, 1972); field methods of buried bag ion exchange resins (Eno, 1960) or membranes (Schnabel, 1983; Qien et al., 1993), soil nitrate-N testing (Magdoff et al., 1984); and plant tissue testing during the growing season (Rice and Havlin,
Research Category: Innovation Grants
The University of MN publication 08560 and related regional publications provide guidance on N rate choices for corn farmers in Minnesota. In addition, the MRTN calculator developed by Iowa State University (http://cnrc.agron.iastate.edu/) is a tool that is more dynamic and responsive as a decision support tool that utilizes state or regional data. This tool recommends fertilizer rates that are adjusted by economic factors including corn and fertilizer price ratios. The MRTN database at version 1.8 for Minnesota has 87 sites of corn-soybean data and 58 sites of continuous corn.
Split application of nitrogen has gained popularity with growers on corn acres as a way to potentially increase nitrogen efficiency, crop yields, net profit, as well as decreasing nitrogen loss. This typically means applying a portion of nitrogen pre-plant, followed by a seasonal application (top-dress) at the V4 to V7 growth stage. Recently, a number of VRN systems have been developed to further refine the rate of nitrogen applied during the top-dress application. The rate of top-dress nitrogen depends on a number of factors: yield history,
The demonstration site has been in a corn soybean rotation with conventional tillage. The field is well drained and has been grid sampled for fertility levels. The field has 13 years of yield data and RTK is used for planting consistency. The demonstration site is currently permitted for 58 acres of irrigation or 9.6 million gallons of water per year to be pumped from the Yellow Medicine River with the MNDNR permit # 2016-0797. A drip irrigation system CAD design has been designed by Maxwell Irrigation.
We are seeking to remodel and add equipment to our current 36 row side-dress bar for applying 28% nitrogen to our corn crop. We would like to add a cover crop system to this applicator to apply seed mixture in between our corn rows to get established and then flourish as corn canopy dries down in the fall. We are also designing this applicator to be a “strip freshener” for our strip tilled rows in the spring by being able to offset the hitch 11nches to work with our 22 inch rows.
This proposal is intended to monitor the nitrogen requirement and overall fertilizer cost contrasting fall applied hog manure with side-dress nitrogen, strip till with side-dress nitrogen, and conventional tillage with side-dress nitrogen. To do this several nitrogen modeling tools will be utilized (Adapt-N, Encirca, and Climate FieldView).
The test will provide results regarding the accuracy and usability of several commercially available nitrogen modeling tools. Deliverables will include cost analysis of each method of nitrogen use Cost/Pound of Nitrogen,
Proper tillage seems to be a never ending struggle for farmers across America. Fred Below, University of Illinois, states that tillage is only number 5 as one of the 7 wonders of corn production. However, improper tillage can be detrimental to corn growth and yield. To address the cost of improper tillage, we would like to put a few different conventional tillage practices to the test in our own backyard. This will create yield data for area growers to compare when struggling to decide what is right for their operation and to understand the cost associated with malfunctioning tillage tools.
With all the different types of applicators of nitrogen on the market, I want to study the efficiency of placement, rater and timing. I want to find that I can cut my nitrogen rates without sacrificing yield. Find the least pounds of nitrogen applied per bushel produced.
As greater focus is placed on nutrient reduction strategies, identifying better methods of nitrogen management becomes more critical than ever. Relying on some of the standard historical nitrogen management practices will no longer be an options as they may not be accepted as a best management practice moving forward. An impulsive reaction may be to assume that nitrogen rates will have to be drastically reduced, but what is really needed is to just look at managing nitrogen differently.
With so many options on the market of nitrogen models and tools, it is a natural tendency to avid change. There is a sense of security to continue with management strategies that have been regularly used in the past. This is especially true if there seems to be no major issues or yield loss. The problem with this is the expectations and demand that are coming down the road for those in the ag industry based on the proposed regulations,