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4R Impacts Grower Cost and Environment on Wisconsin Farm

This 1,150 acre western Wisconsin farm operates a medium-size beef feedlot and grows in rotation alfalfa, corn silage, and corn grain. The solid beef pen pack manure is farmer applied to corn land. The farm also adds some liquid dairy manure that is custom applied to help meet crop nutrient needs. The remainder of the crop needs are applied in-season.

Outcome

This farm with multi-year and crop rotation has a dynamic response in cost of practice change and nutrient use efficiency. Looking at corn silage production over three years, on average the farm decreased cost per acre as they transitioned to intermediate 4R practices. As the cost decreased on average, the nitrogen use efficiency and nitrogen balance increased over time. This is happening for two reasons. One, the farm is doing an excellent job of crediting the nitrogen that is accumulated in the soil from the alfalfa portion of the rotation into their nitrogen applications. And two, beef manure is applied pre-plant supplying nitrogen to the early growing crop. These are strong practices for building soil health and organic matter.

The nitrogen balance is always negative with the corn silage years and lower in years where there is more first year corn silage. The rotation to alfalfa and the organic nitrogen from the residual beef manure that remains over time helps meet the nitrogen needs of the corn silage crop.

When the crop rotation is corn grain with alfalfa, the accounting for nitrogen from the alfalfa cost did go up as practices shifted to intermediate, but the lower cost in the first year corn is due to the lower fertilizer application from accounting for the nitrogen from the alfalfa crop.

Intermediate Practices Implemented

In 2018, the farm transitioned from applying nitrogen pre-plant to an in-season side dress for nitrogen requirements and added software for managing records and weather impacts on nutrient applications. Through all years, the farm is crediting all nutrient sources and adjusting fertilizer needs based on the nutrient contributions from those sources.

Cost and Environmental Data

Year2016201720182019
CropCorn SilageCorn SilageCorn SilageCorn Silage
Cost ($/acre)$249.10$208.03$165.80$92.70
4R Practice LevelBasicBasicIntermediateIntermediate
Nitrogen Application Rate (lbs/ac)8917321895
Nitrogen Use Efficiency (lb N applied/bu of corn grain)2.95.26.63.8
Nitrogen Balance (lb N applied – lb N harvested)-181.4-115-69.9-123.3
Phosphorus Application Rate (lbs/ac)60735340
Yield (bu/ac)31333325

Cost of 4R Practice Implementation for a Multi-Crop Rotation

Year2016201720182019
Crop (Tons/acre)Alfalfa HayCorn GrainCorn GrainCorn Grain
Cost ($/acre)$137.86$108.55$172.53$154.21
4R Practice LevelBasicBasicIntermediateIntermediate
Nitrogen Application Rate (lbs/ac)1533182179
Nitrogen Use Efficiency (lb N applied/bu of corn grain)3.330.201.011.19
Nitrogen Balance (lb N applied – lb N harvested)-89-934968
Phosphorus Application Rate (lbs/ac)30737360
Yield (bu/ac)4.5 tons/ac170180150

Illinois corn farm sees 34% emissions decreases while also lowering cost per acre

This family farm located in central Illinois is managed by a young farmer who was an early adopter of the 4Rs. Seeing the benefits of these practices and willing to make investments in the farm, the family made advanced leaps in adoption of 4R practices and saw immediate returns.

When moving from basic to advanced 4R practices the total cost per acre to implement 4R practices decreased due to reduced fertilizer and equipment costs. Operation cost of an in-season sprayer and use of a smaller tractor for in-season nitrogen injection also lowered costs.

The time spent per acre implementing 4R practices was 0.21 hours per acre for basic practices compared to 0.22 with advanced practices, due to more fertilizer applications per season.

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Outcome

Changing from basic to more advanced 4R practices, the farmer decreased cost per acre between $16.49 and $25.31, while also decreasing CO2 equivalent greenhouse gas emissions by 34.7 percent.

Cost of 4R Practice Implementation for Illinois No-Till Corn

Intermediate to Advanced Practices Implemented

  • Expanded soil sampling from small 1-acre grid in 2016 to 2.5-acre grid in 2019.
  • Fertilizer applications are applied using variable rate equipment.
  • All nitrogen applied in-season

Zone-Based Variable Rate

On all fields:

  • Fall variable rate application of MAP and potash based on grid soil sampling and yield data
  • Variable rate seeding based on zones and incorporating use of software for in-season decisions

2014 – Basic 

  • Spring pre-plant anhydrous ammonia injected with nitrification inhibitor
  • Liquid starter with seed (6-24-6 at 3.5 gallons per acre)
  • Early-post with herbicides nitrogen application (32 percent UAN at 10 gallons per acre)
  • Liquid nitrogen side-dress with y-drops (32 percent UAN)

2015 – Basic

  • Spring pre-plant anhydrous ammonia injected with nitrification inhibitor
  • Liquid starter with seed (6-24-6 at 3.5 gallons per acre)
  • Early-post with herbicides nitrogen application (32 percent UAN at 10 gallons per acre)
  • Liquid nitrogen side-dress with y-drops (32 percent UAN)

2016 – Intermediate

  • Liquid starter with seed (6-24-6 at 3.5 gallons per acre)
  • Early-post with herbicides nitrogen application (32 percent UAN at 10 gallons per acre)
  • Side-dress anhydrous ammonia injected with nitrification inhibitors

2017 – Advanced

  • Liquid starter with seed (6-24-6 at 3.5 gallons per acre)
  • Early-Post with herbicides nitrogen application (32 percent UAN at 10 gallons per acre)
  • Side-dress anhydrous ammonia injected with nitrification inhibitors
  • Liquid nitrogen side-dress with y-drops (Corn stage V10; 32 percent UAN with variable rate application)

Environmental Metrics

year2014201520162017
4R Practice LevelBasicBasicIntermediateAdvanced
Nitrogen Application Rate (lbs/ac)253208253204
Nitrogen Use Efficiency (lb N applied/bu of corn grain)1.11.951.030.8
Nitrogen Balance (lb N applied – lb N harvested)69.531.956.6-1.14
CO2e Emissions per Bushel9.48.438.176.14
CO2e Percent Reduction–10.313.134.7
Yield229220245256