1. Soil Fertility in Muskogee County
Rodney King
Extension Educator, Agriculture

2. Essential Plant Nutrients
Major Nutrients
Nitrogen
Phosphorus
Potassium
Secondary Nutrients
Calcium
Sulfur
Magnesium
Micronutrients
Iron, Manganese, Zinc, Copper,
Chlorine, Boron, Molybdenum
Carbon, Hydrogen, Oxygen

3. Comprehensive Salinity Management
Soil Tests
Routine pH
Buffer Index
Nitrogen
Phosphorus
Potassium
Secondary Nutrients
Sulfate-Sulfur
Magnesium
(Calcium for peanuts)
Micronutrients
Iron
Zinc
Boron
Subsoil Nitrate
Organic Matter
Chlorine
Salinity Management
Comprehensive Salinity Management

4. Mobility of Nutrients in Soil
Mobile Nutrients
Nitrogen
Sulfur
Boron
Chlorine
(Fuel Tank)
Immobile Nutrients
Phosphorus
Potassium
Calcium
Mg, Fe, Mn, Cu, Zn, Mo
(Crankcase)

5. Plant absorption of Nitrogen.
Fuel Tank Nutrient
Plants absorb N from large volume of soil.

6. Crop absorption of immobile nutrients (P and K).
Immobile nutrients can buildup to adequate levels (crankcase)

7. Nitrogen Requirement Crop to be grown Yield goal N requirement
N needs = N requirement - Soil NO3-N
Credits for subsurface and manure N

8. Fertilizer Recommendations
Nitrogen Based on Yield Goals Introduced Forages – 50 lbs N/Ton Corn – 1.2 lbs N/Bushel Wheat – 2 lbs N/Bushel
Phosphorus and Potassium based on % sufficiency – Recommendation is amount needed annually to achieve optimum yields

9. Nitrogen Deficiency in Wheat Pasture.

10. Bermudagrass Response to N
N Rate 50
100
150
200
Expected Yield
1.0
1.8
2.8
3.4
3.9

11. 3 ton yield goal
142 lbs N/A

12. Calibration Stamp
Ramped N Rich Strip 2005

13. In season environmental conditions
Handheld Unit –
Temporal Variability
In season environmental conditions
6 handheld GreenSeeker™ units located in Extension Offices

14. Muskogee Co. NO3 lbs/A 2006
294 samples
Range

15. Phosphorus Requirement
Soil test P index (Mehlich 3 method)
Percent sufficiency
P requirement (P2O5 lbs/acre)

16. 65
Full Mark on
Dipstick
Very low

17. 250
Full Mark on
Dipstick
Low

18. Percent Sufficiency Phosphorus Index - 9 64% Sufficient
Potassium Index % Sufficient
.64 X .84 = % Sufficient
Would expect 54% of optimum yield if P and K are not applied.

19. Bermudagrass/Fertilizer Demo. Mayes Co
Bermudagrass/Fertilizer Demo. Mayes Co. Fertilized May 12, Harvested August 5, 1997
Yield
lb./a
Nitrogen Rate

20. Muskogee County P index 2006
294 samples
Range

21. Muskogee County K Index 2006
294 samples
Range 56 – 2,301

23. Legumes, Grain Sorghum, Wheat, Corn 5.5 – 7.0
pH preference
Legumes, Grain Sorghum, Wheat, Corn 5.5 – 7.0
Fescue 4.5 – 7.0
Bermudagrass 5.7 – 7.0
Alfalfa 6.5 – 7.5

24. Muskogee County pH 2006
294 samples
Range 4.2 – 7.7

25. Muskogee County B.I. 2006 Buffer Index Lime (T ECCE/A) 7.1 0.5 7.0 0.7
6.9
1.0
6.8
1.2
6.7
1.4
6.6
1.9
6.5
2.5
6.4
3.1
294 samples
Range 5.9 – 7.2

26. 22 lbs of S is adequate
for 8 + T/A

27. 750
Ca deficiency is unlikely
pH will be a problem before Ca

28. 100
High yields on soils that are subject to leaching

29. 2 PPM

30. .3 -.8 Deficient for corn and pecans

31. >.5 sufficient for all crops
Boron only a concern
with peanuts or
alfalfa

32. None are deficient in Oklahoma
Other Nutrients
Chlorine
Copper
Molybdenum
Manganese
None are deficient in Oklahoma

33. Interactive Website for Detemining Fertilizer Value
Oklahoma State University - Soil, Water and Forage Analytical Laboratory