By answering a few questions, we can help you determine which 4R practices might work for your farm. Talking to your ag service provider or crop adviser is the best way to plan your 4R fertilizer strategy.
When do you apply phosphorus fertilizer?
On frozen or snow-covered ground
After harvest but before the ground freezes
Just before or at planting
When a crop is growing (in season)
Where do you apply your phosphorus fertilizer?
Surface application with no incorporation
Surface application followed by conventional tillage
Surface application followed by minimum tillage or by strip-tillage
With the seed
How many times in a season do you apply nitrogen fertilizer?
More than 3 times
Do you add a nitrogen stabilization product to your nitrogen fertilizer?
When weather and soil conditions dictate the need
When is the last time you took soil samples for your fields?
I have never taken soil samples
More than 6 years ago
4 years ago
Within the last 2 years
How many acres are sampled for a soil sample on your fields?
More than 40
25 to 35
15 to 25
Fields are sampled based on grids or zones and areas less than 10 acres
Do you use tissue testing to determine crop nutrient needs?
Only when a problem is seen – as a diagnostic tool
Only for micronutrient applications
Before all in-season applications to adjust rate
How do you determine nitrogen fertilizer rates for a crop?
Apply based on past practices
Consider University or Extension recommendations
Evaluate past yield and crop removal
Combine soil test results, past yield, expected yield, soil characteristics, and crop quality testing
How do you apply your nitrogen fertilizer?
Surface application no incorporation
Broadcast and incorporated within 10 days
Broadcast and incorporated within 48 hours or surface applied as a sidedress
Injected or subsurface banded or sidedress with N inhibitor products
How are in-season N rates determined?
Don’t do an in-season application
Remainder of total recommended rate for the season
Tissue or PSNT test
Tissue test or PSNT, plus modeling that accounts for within field variability and weather
How is the risk of phosphorus loss from field determined?
It is not evaluated
Soil test P values
Soil test P values and distance to waterways
Use of a phosphorus index tool
Do you consider and fertilizer for micronutrient crop requirements?
Only when a deficiency is observed
Only for sensitive crops
Soil test for micronutrients and balance for all nutrient in applications