New technologies for improving sustainability of corn N management

New technologies for improving sustainability of corn N management

Summary

Since the summer of 2013 when this funding source became available, we have made significant progress in gathering a third year of data for calibration and validation through on-farm beta-test trials we are leveraging from other sources, in improving the Adapt-N tool, and in moving forward the new indicators for the Cornell Soil Health Test that are on target to be offered in 2014. We have also made tremendous progress in educating stakeholders about the importance of adapting N inputs in corn systems to weather impacts by moving to dynamic N rate decisions made at sidedress time, and about the contributions of soil health to nitrogen dynamics. At this point it appears that Adapt-N can save growers money: $20 – $30 per acre in dry years can be expected, but potentially much more in a wet year when the profit gains come from avoiding yield loss: from preliminary trials we are seeing increased profits on average of over $50 per acre. In 2011-12 growers prevented excessive N inputs (on average 54 lb per acre), while in 2013 growers learned hard lessons about their poor N timing practices (bulk of N applied pre-plant or as starter). In many cases growers who apply most of their N early had significant losses, and needed to apply further N to avoid yield loss. Many such growers are now rethinking their strategy, as these findings provide strong incentive for growers to move to more sidedress applications of nitrogen, and thus manage the risk and actual needs better. We are also starting to ramp up for the work laid out for this project. We have been in contact with collaborators regarding expectations for next year, and a subset of the team (Bianca Moebius-Clune, Matt Ryan, Steven Mirsky, and Jeff Melkonian) have been working on the new cover crops module to be introduced for beta-testing in the spring of 2014.

Objectives/Performance Targets

Planned for this time period: 1500 farmers and advisors gain understanding of dynamic, in-season N management with tools like Adapt-N and multi-purpose/high-clearance equipment for sidedressing and cover crop establishment, through field days, winter meetings, and newsletter articles. (Aug 2013-Mar 2014)

Progress: Just between August and now we have directly reached over 500 stakeholders through our workshops, presentations, and field days. Many more events are being planned for the winter.

Accomplishments/Milestones

There is more interest in Adapt-N by the week both at the state as well as the regional and national level. Just between August and now we have directly reached over 500 stakeholders through our workshops, presentations, and field days. Many more events are being planned for the winter. Additionally we have been maintaining the blog on our website and we are close to completion on the Adapt-N Training Manual we have been developing. It will be posted at http://adapt-n.cals.cornell.edu/manual/index.html as soon as it is ready – planned for early January.

BETA-TESTING RESULTS:

2012 NY data analysis was completed and the 2011-2012 results summary was published this fall in the Vol. 97, 2013, No. 4 issue of IPNI’s Better Crops publication. All recent publications are available on our website (http://adapt-n.cals.cornell.edu/pubs/index.html). Data from eighty-four on-farm trials between 2011 and 2012 were analyzed, including 56 trials in NY. Results showed that in dry and normal weather conditions, Adapt-N can decrease N inputs without causing yield losses. Over the two years, Adapt-N application rates were reduced on average by 66 lb/ac in NY in comparison to current grower practice, while average yield losses with Adapt-N were only -1 bu/ac (not statistically significant). Adapt-N thus increased profits in 80% of trials in, with average increases of about $31/ac due to fertilizer cost savings. The lower Adapt-N sidedress rates also significantly reduced N loss to the environment, with end-of-season simulated leaching losses decreasing by 10 lbs N/ac, and simulated total N losses decreasing by 34 lbs N/ac on average. Highlights in 2012 included the case study at Donald and Sons Farm in Moravia, NY, where N reductions of 67,000 lb in 2012 saved the farm over $30,000. The Donalds continue to use Adapt-N recommendations across their fields, and implemented 9 trials in 2013.

On-farm testing of Adapt-N continued in 2013, and we expect to receive data from at least 100 trials nation-wide (at least half from the Northeast) from this season. After relatively dry or average weather conditions throughout most of the user area in 2011 and 2012, 2013 provided a stark contrast. This spring was extremely wet in most of our user area, causing large losses of early-applied N through both leaching and denitrification. Particularly first-time Adapt-N users, who sought out the tool to try to account for the impact on their preplant applications, were shocked to find, in many cases, that most of their investment in N had been lost by early-mid June. In a wet year like this, the benefit of Adapt-N to farmers comes from increasing N rates where needed in order to avoid major yield losses. The long-term value comes from Adapt-N instigating paradigm shifts as farmers recognize the high risk for loss of early-applied N, and rethink their management systems to consider sidedress applications.

Preliminary 2013 results are generally positive. Of 14 NY trials preliminarily analyzed to date, Adapt-N performed well in 9, with average yield increase of 12 bu/ac and profit increase of $52/acre due to the tool (five silage yields are reported as grain equivalent). Adapt-N sidedress rates were higher than the grower’s normal practice in 8 NY trials, all of which resulted in yield and profit increase (from +4 to 58 bu/ac and +$12 to $246/ac.) The five NY trials that resulted in profit loss (three silage and two grain) indicate two things: 1) potential opportunities for further refinement of the simulation model with consideration of soil health characteristics: losses were found in small long-term tillage experiments in continuous corn, and 2) the need for more precise user inputs, especially related to manure applications, and probably an adjustment of the risk factor used for the higher uncertainty inherent in manured scenarios, as affected by uneven or imperfectly calibrated manure spreading and not-ideally-representative testing. The silage trial with the highest yield loss was a volunteer trial using a single-check-strip with no replication. We will need to review background information on this trial. Without this trial, average benefit in NY rises to a 16 bu/ac yield increase and $73/ac profit increase with an increase of only 12lb/ac of N on average, indicating that mostly N inputs are reduced or increased respectively, as justified by weather impacts. All trials are being reviewed for accuracy.

Some highlights among the 2013 trials have come from Keith Severson at Cayuga County Cooperative Extension. Keith worked with grower Arnold Richardson (see Impacts section, below) to establish Adapt-N trials in three of Richardson’s fields. Due to N loss from early spring wetness, Adapt-N recommended sidedress N rates that were 20, 30, and 40 lbs/ac higher than Richardson’s normal practice. The higher rates resulted in yield gains of 23, 23, and 30 bu/ac, and profit gains of $102, $95, and $128 per acre, respectively. Additional highlights come from volunteer collaborator Dave DeGolyer at Western NY Crop Management Association, who established several trials with grower Donn Branton (see Impacts section, below). By applying 60 lb N/ac at sidedress because Adapt-N indicated that preplant applied N had largely been lost, Branton saw increases of 25, 42, and 58 bu/ac in three trials and profit gains of approximately $79, $164, and $246/ac due to avoided yield loss. We look forward to analyzing the majority of the 2013 data that have not yet come in, and using results to further refine the model’s ability to account for the impact of weather on N availability.

ADAPT-N IMPROVEMENTS:

We are currently working on several feature improvements for spring 2014:
– The beta cover crops module. This will put in place a way that users can start to account for the impacts of cover crops. The planned version will include inputs for cover crop species (including mixes), growth stage and biomass at termination, C:N ratio at termination, method and date of termination, and several of these will have defaults and guidance on choices available. The model is currently being calibrated with data from collaborator Steven Mirsky.

– Improvements to the way the model handles over-winter processes and drainage characteristics of soils, and soil dictionaries for additional Northeast states and the ability to estimate nitrous oxide emissions are being added (leveraging funds from other sources)

– Improvements to the price ratio and risk correction factors used for scenarios with different risk or price ratio are being evaluated based on trial results thus far.

Impacts and Contributions/Outcomes

These 2013 results preliminarily suggest that Adapt-N is equally useful as a tool for calculating needed N increases during wet years, as it is for avoiding excess N in normal years, and can result in large economic benefits to farmers through avoided yield loss. While there are no immediate environmental benefits of Adapt-N recommending higher rates in a wet year, we anticipate that the impact of this reality on farmers will be to encourage many more farmers to shift their N applications to sidedress time, and this will then have significant positive environmental impact in future years (both wet and dry).

A specific example of impact on farm-management practices that we know about now is taking place in Western NY, based on Donn Branton’s trials above. Donn’s standard N management for years has been to place all N fertilizer in a deep slot at planting. He has not been sidedressing. However, this year it became very evident that such fertilizer is in fact very vulnerable to losses during heavy rains, and thus more N was needed at sidedress time despite the fact that enough would have been available in a normal year. The Brantons are now rethinking their N management and are considering making sidedressing a standard practice. They are likely to decrease their preplant N applications significantly, and apply N using Adapt-N recommendations as one of their decision tools.

Dave Degolyer and colleagues are planning to sample about 600 acres (about 30 fields) of Donn Branton’s fields in the next days. They will submit soil health test samples to both Cornell and Ward Lab (for the new Haney Soil Health Tool). They will send composites of whole fields for each field for soil health analysis, but will take split samples (by soil type and yield map) for nutrient and organic matter analysis. Of these fields about 300 acres will go into corn grain next year. They plan to run Adapt-N by management unit within fields, basing their expected yields on past yield history from their yield monitors. They plan to send us splits of the by-management-unit samples as well so that we can run these throughout new N-dynamics-related soil health indicators (respiration and proteins). Donn and his son Chad have expressed interest in providing data for calibrating the beta soil health module for Adapt-N that we have some funding for so far. The will leave us short 0-N sections and report on yields across the fields. Some cover cropped fields will be included in this set, so will also help us with calibrating our beta cover crops module.

Collaborators: