1. Soil Fertility Management for Forage Crops 25 th Annual FL Cattlemen’s Institute and Allied Trade Show Maria L. Silveira Soil and Water Science University of Florida – Range Cattle REC

2. Essential Elements for Plants  Primary nutrients: Nitrogen, Phosphorus, Potassium  Secondary nutrients: Calcium, Magnesium, Sulfur  Micronutrients: Zinc, Manganese, Iron, Copper, Boron, Molybdenum, Chlorine  Carbon, Hydrogen, and Oxygen M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

3. Soil Fertility and Forage Production M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC Soil fertility management is a continuous process that begins before forages are established Yield will be limited by the element in shortest supply in relation to plants needs

4. Soil Fertility and Forage Production M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

5. Soil Fertility and Forage Production M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

6. Soil Fertility and Forage Production M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

7. Soil Fertility and Forage Production M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

8. Soil pH

9. pH 4.4 pH 5.7 M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC pH 5.6 pH 4.3

11. Effect of soil pH on fertilizer efficiency pHNPK ------- Fertilizer Efficiency (%) ------- 4.5218 5.0381030 5.5521545 6.0631560 7.0703060 M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

12. Target pH for different forage crops grown on mineral soils 1 Crop CategoryTarget pH Bahiagrass5.5 Bermudagrass, stragrass and limpograss 5.5 – 6.0 Small grains and ryegrass6.0 Perennial peanut6.0 Clover6.5 Alfalfa7.0 1 C. G. Chambliss, G. Kidder, and R. Mylavarapu. 2003. Liming for Production of Forage Crops in Florida. EDIS SS-AGR-46.

13. Characteristics of liming materials  Lime, calcite, dolomite, calcitic and dolomitic limestone, aragonite.  ECCE = effective calcium carbonate equivalence M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC ECCE 100% ECCE 40% ECCE 10% Photo: University of Nebraska

14. Importance of Soil Test M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

17. Soil Test  Soil sample collection: representative of the entire area of interest Minimum of 15-20 subsamples Differences in soil type Areas managed or cropped differently Areas that clearly have some type of problem M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

18. Soil Test  Handling and submitting your soil sample 1. Samples are thoroughly mixed 2. Sub-sample should be placed in a clean and properly labeled soil sample bag 3. Samples should be delivered to lab as soon as possible after collection M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

19. Soil Fertility and Forage Production SOIL TEST RESULTS AND THEIR INTERPRETATION - Target pH: 5.5 - pH (1:2 sample:water): 5.1 - A-E Buffer Value: 7.3 Mehlich-1 Extractable V LowLowMedHighV High Phosphorus 12 Potassium 4 Magnesium 30 Calcium 112

20. 60” Tissue Test Photo: Dr. C. Mackowiak

21. Tissue Test M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC Tissue concentration DeficientLow Sufficient High Excess Crop Yield Critical range

22. Plant Tissue Sampling M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC Sample collection and handling are crucial Bahiagrass should be sampled prior to seed head emergence The four uppermost leaf blades should be sampled Critical P concentration for bahiagrass = 0.15% Photo: Dr. C. Mackowiak

23. Changes in Fertilization Recommendations for Established Bahiagrass Pastures 1. Soil sampling is recommended for the entire State 2. Soil pH ≥ 5.5 (if pH is below 5.3, lime should be applied) When necessary, lime should be applied at least 3 to 6 months prior to fertilization 3. Phosphorus fertilization Phosphorus fertilization is recommended when soil test is very low or low in P and tissue concentration is < 0.15% M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

24. Changes in Fertilization Recommendations for Established Bahiagrass Pastures Low N option (50-60 lb N/A) - K is not recommended - Apply 25 lb P 2 O 5 /A if soil tests very low or low in P AND tissue concentration is below 0.15% Medium N option (100 lb N/A) - Apply 50 lb K 2 O/A if soil tests very low or low in K - Apply 25 lb P 2 O 5 /A if soil tests very low or low in P AND tissue concentration is below 0.15% M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

25. Changes in Fertilization Recommendations for Established Bahiagrass Pastures High N option (160 lb N/A) - Apply 80 lb K 2 O/A if soil tests very low or low in K. Apply 40 lb K 2 O/A if soil tests medium in K. - Apply 40 lb P 2 O 5 /A if soil tests very low or low in P AND tissue concentration is below 0.15% M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

26. Summary M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC Soil Test PTissue TestRecommendations Med/HighNo tissue test 0 Very Low/LowP ≥ 0.15%0 Very Low/LowP < 0.15%25 or 40 lb P 2 O 5 /A ‡ ‡ Based on N option

27. Flow Chart – Bahiagrass Recommendations M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC Soil SamplePlant Tissue Sample Soil test P, K, Ca, Mg, lime requirement and tissue test Soil tested very low or low in PSoil tested medium or high in P Tissue P < 0.15%Tissue P ≥ 0.15% P recommendation No P fertilizer Soil test P, K, Ca, Mg, lime requirement Soil pH > 5.3Soil pH < 5.3 No P fertilizer

28. THANKS M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC Questions?