Crop Model Field Report: Final

Last summer and fall, WinField United tested and aggregated the in-season recommendations of the R7^® Field Forecasting Tool across the country on what we’re calling Sentinel Plots. Throughout the season, we’ve talked with the agronomists who are managing several of these plots and have posted periodic updates about what the tool has recommended, what actions have been taken as a result and what progress is looking like at that point in time.

All Sentinel Plots are planted in corn. We published the first installment of the series in late July, the second installment in August and the third installment in October. Here is the fourth and final installment of the Sentinel Plot series.

Sentinel Plot location

Southeastern Illinois

Date reported

December 6, 2019

Growth stage

Corn was harvested off this Sentinel Plot on September 19.

Agronomist

Jason Haegele

This Sentinel Plot was situated on sandy, irrigated land along the Wabash River. The farmer who owns the land was interested in learning some in-season management strategies he could use to really push yields.

Timely harvest, accurate yield prediction

We had a timely harvest of this Sentinel Plot in September. This was a relatively small field and had been planted in late April due its sandy soil. Crop quality was good, but that was mostly a function of the hybrid, which was expected to have good grain quality.

The final yield for the plot was 250 bushels, and the Field Forecasting Tool predicted 246 bushels. This is very good accuracy considering the challenges that 2019 presented and the multiple in-season nitrogen and sulfur applications that were made to this field. Interestingly, the weather issues we encountered in 2019 were not particularly deleterious to the Sentinel Plot because a coarse-textured soil can actually be an advantage in a wet year.

Using the tool this season and next

In 2019, we used the Field Forecasting Tool primarily to model different nitrogen application scenarios and to decide when to stop making in-season nitrogen applications through the irrigation system. I anticipate using the tool in a similar way next season for corn. I’m also excited to use the tool in a new way in 2020 — with irrigated soybeans to better manage water applications in order to limit the potential for lodging.

The farmer whose land we used for our 2019 Sentinel Plot was pleased with the yield that was achieved and the strategies we used to arrive at that yield. I believe he is excited to replicate it again in 2020. I anticipate other farmers in my area adopting the Field Forecasting Tool as a way to better manage nitrogen and monitor in-season yield potential.

Final thoughts

Overall, I was extremely happy with the performance of the Field Forecasting Tool and our Sentinel Plot program. This was a fun project that allowed me to work with an individual farmer to help shape his decisions and help him achieve an excellent corn yield.

If we had not used the Field Forecasting Tool, the approach to managing this field probably would have been to apply one application of nitrogen fertilizer around the time of planting and then water the crop every week or every other week depending on rainfall. Although we don’t know what the yield would have been using this approach, I am confident that we would not have achieved 250 bushels. The Field Forecasting Tool provided another way to evaluate in-season management decisions for a better outcome.

In addition to using the Field Forecasting Tool again on corn and on irrigated soybeans in 2020, I’m looking forward to using the tool with some of the new disease models along with our NutriSolutions® tissue and soil analysis to monitor fields for disease, crop development and nutritional status.

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Sentinel Plot location

Southwestern Kentucky

Date reported

December 10, 2019

Growth stage

Corn was harvested off this Sentinel Plot on September 11.

Agronomist

Darrin Holder

This Sentinel Plot is situated on nonirrigated land. The farmer applied 100 units of nitrogen (anhydrous ammonia) about two weeks prior to planting. Corn was planted around April 11 using a variable-rate seeding method. An additional 84 units of nitrogen was applied at V9 using ammonium sulfate and ammonium nitrate. One hundred pounds of urea was flown on at V17 for an additional 46 units of nitrogen.

Smooth harvest, on-target yield estimate

Weather was not a huge factor in our harvest and did not affect the Sentinel Plot at all. Crop quality was good from plant standability all the way to grain test weight, and the Field Forecasting Tool accurately pinpointed moisture levels. Actual final yield was 192 bushels per acre, with the Field Forecasting Tool putting yield at 184 bushels per acre. That’s less than a 5% difference, and I was very pleased with the yield and accuracy of the model.

Using the tool in-season

This season, I used the Field Forecasting Tool to fine-tune side-dress and pretassel nitrogen recommendations, and to determine whether or not to spray a fungicide (based on yield level and if it was worth protecting). The farmer was pleased with the accuracy of the tool and the insights it generated to help us make data-backed decisions throughout the season.

In 2020, I plan to monitor this field again even though it will be in soybeans. I also plan to monitor another Sentinel Plot on an adjacent farm that will be in corn, similar to how we handled the plot this year. I see farmers using the Field Forecasting Tool in the coming year in multiple ways — from doing something fairly simple like fine-tuning nitrogen recommendations to advising on something as complex as spoon-feeding the crop everything it needs. I also plan to use this past season’s potassium model to have discussions with farmers about future potassium fertility programs.

Final thoughts

I was very pleased with the performance of the Field Forecasting Tool in regard to the Sentinel Plot and didn’t have any surprises in the field. Most importantly, the tool helped me make more insightful nitrogen decisions based on what had happened up to that point in the season rather than what had always been done. I do believe the tool helped improve the ROI of that particular field, and our nitrogen use efficiency was good.

The one function of the tool that I didn’t use this year that I’d consider using in 2020 is employing tissue sample results to better gauge the efficiency of nutrients other than nitrogen, phosphorus and potassium. I’d also like to use Climate FieldView™ or a yield map from the combine to see how different zones of the field performed to determine if we should have applied nitrogen differently.