1. Using Sensors and Lime Reference Strips to Manage Soil Acidity
Hailin Zhang
Randy Taylor
Oklahoma State University

2. Acid Soils in Oklahoma

6. Variety Response to Soil pH
Limed
Not Limed
Custer, Ok101, Jagalene, Jagger, , AP502Cl, Ok102, 2137

7. pH 5.1
pH 4.5
Al toxicity is very obvious in some years. It is resembles the symptoms of P deficiency. Roots are severely impact in low pH soils.

9. Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.

11. Production Induced Soil Acidity
No-till
Normal tillage

12. How to deal with acid problems?
Band phosphate fertilizer with seeds to tie up Al
Plant Al tolerant wheat varieties
Apply aglime to neutralize acidity
Do nothing
Those are very effective remedies, but they are temporary and do not change soil pH. Apply ag-lime has been proving a effective.

13. Long-term Liming on Wheat Haskell, OK
Dr. Krenzer and others in this department conducted another lime study in the early 90’s. They found significant forage response but not grain response either.

14. Relative Fall Wheat Forage Yield

15. Cost and Benefit at 1.25 tons/A
The lime effect lasts much longer than three years as indicated by the current soil pH and previous experiments.
To mimic cattle grazing
Cost

16. Soil pH changes with time after lime was applied at 7 lime rates (t/ac ECCE).

17. Introduce a Lime Reference Strip used with or without an N-rich strip in acid soils to show the benefits of liming
Lime Reference Strip
Nitrogen strip
Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.

18. A 60 ft. lime strip was placed in 4 fields in 2007
At about 1 ton ECCE/acre
Two no-till fields near Apache
Two conventional tilled fields near Enid
Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.

19. RI = 1.08 NDVI = 0.50 NDVI = 0.54 pH 5.0 pH 5.0, Limed
Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.
pH 5.0
pH 5.0, Limed

20. RI = 1.11 NDVI = 0.64 NDVI = 0.57 pH 5.5, Limed pH 5.5, not Limed
Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.
pH 5.5, Limed
pH 5.5, not Limed

21. RI = 1.04 NDVI = 0.59 NDVI = 0.62 pH 5.2, not Limed pH 5.2, Limed
Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.
pH 5.2, not Limed
pH 5.2, Limed

24. Using Sensor to Map Wheat Forage Yields

25. Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.

26. CONCLUSIONS
Soil becomes more acidic with continuous production and N fertilizer application
Active Al increases as soil become more acidic
Grain and forage yields are both impacted by soil acidity
Liming is an effective remediation
Lime reference strip and sensor can demonstrate the benefits of liming