Soil Fertility Management for Forage Crops 25 th Annual FL Cattlemen’s Institute and Allied Trade...
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Transcript of Soil Fertility Management for Forage Crops 25 th Annual FL Cattlemen’s Institute and Allied Trade...
Soil Fertility Management for Soil Fertility Management for Forage CropsForage Crops
2525thth Annual FL Cattlemen’s Institute Annual FL Cattlemen’s Institute and Allied Trade Showand Allied Trade Show
Maria L. SilveiraMaria L. SilveiraSoil and Water ScienceSoil and Water Science
University of Florida – Range Cattle RECUniversity of Florida – Range Cattle REC
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
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
Soil Fertility and Forage Production
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
Soil Fertility and Forage Production
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
Soil Fertility and Forage Production
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
Soil Fertility and Forage Production
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
Soil pH
pH 4.4
pH 5.7
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
pH 5.6
pH 4.3
Effect of soil pH on fertilizer efficiency
pH N P K
------- Fertilizer Efficiency (%) -------
4.5 21 8 21
5.0 38 10 30
5.5 52 15 45
6.0 63 15 60
7.0 70 30 60
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
Target pH for different forage crops
grown on mineral soils1 Crop Category Target pH
Bahiagrass 5.5
Bermudagrass, stragrass and limpograss
5.5 – 6.0
Small grains and ryegrass 6.0
Perennial peanut 6.0
Clover 6.5
Alfalfa 7.01C. G. Chambliss, G. Kidder, and R. Mylavarapu. 2003. Liming for Production of Forage Crops in Florida. EDIS SS-AGR-46.
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
Importance of Soil Test
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
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
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
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 Low Low Med High V High
Phosphorus 12
Potassium 4
Magnesium 30
Calcium 112
60”
Tissue Test
Photo: Dr. C. Mackowiak
Tissue Test
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
Tissue concentration
Def
icie
nt
Low
Suf
ficie
nt
Hig
h
Exc
ess
Cro
p Y
ield
Critical range
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
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
Changes in Fertilization Recommendations for Established Bahiagrass Pastures
Low N option (50-60 lb N/A)
- K is not recommended
- Apply 25 lb P2O5/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 K2O/A if soil tests very low or low in K
- Apply 25 lb P2O5/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
Changes in Fertilization Recommendations for Established Bahiagrass Pastures
High N option (160 lb N/A) - Apply 80 lb K2O/A if soil tests very low or low in K. Apply 40 lb K2O/A if soil tests medium in K.
- Apply 40 lb P2O5/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
Summary
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
Soil Test P Tissue Test Recommendations
Med/High No tissue test
0
Very Low/Low P ≥ 0.15% 0
Very Low/Low P < 0.15% 25 or 40 lb P2O5/A‡
‡ Based on N option
Flow Chart – Bahiagrass Recommendations
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
Soil Sample Plant Tissue Sample
Soil test P, K, Ca, Mg, lime requirement and tissue test
Soil tested very low or low in P Soil tested medium or high in P
Tissue P < 0.15% Tissue P ≥ 0.15%
P recommendationP recommendation No P fertilizer
No P fertilizer
Soil test P, K, Ca, Mg, lime requirement
Soil pH > 5.3Soil pH < 5.3
No P fertilizer
THANKS
M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC
Questions?