The Florida Lime Study
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Transcript of The Florida Lime Study
Rao Mylavarapu, Nancy Wilkinson, William d’Angelo, Jennifer Frey, Cassandra Admire, Alex Bournique,
Murthy KadiyalaSoil & Water Science Department, IFAS
University of Florida
ObjectiveScreen methods for determination of lime
requirement for acid-mineral soils of Florida
MethodsUniversity of Kentucky - Sikora method Auburn University - Huluka method Clemson University - Sikora-Moore methodUniversity of Georgia - Single Titration
method
Justification
The current Adams-Evans Buffer method involves p-Nitrophenol, an environmentally hazardous chemical
An environmentally friendly alternative method is needed
Primary need, however, is to identify a method that will be effective for acid-mineral soils of Florida
Materials and MethodsCollected 12 soil samples from 10 different counties-
Bradford, Clay, Columbia, Highlands, Hendry, Lake,Marion, Sumter, Putnam (3 samples) and Jackson counties
Samples were dried, sieved through 2.0mm mesh
The 4 methods were replicated 4 times
Water pH (1:2) was determined on all samples
Soil pH ranged from 4.0 to 5.4
AE-Buffer pH was determined and the Target pHs were identified as 6.5 and 6.8
Four replicates of each sample, weighing 200 grams, were sent to each state Lab
Each Lab ran their preferred method and determined the lime requirement and returned the data
Calcitic lime was added to all cups as per the recommendation from each of the state labs and the cups were incubated in the dark for a total of 63 days
Materials and Methods
PreparationThe experiment was replicated 4 times
200 g of sample was weighed into each cupLabeled with county, Lab, lime rate and replicate12 counties labeled from A to L4 Labs were labeled I, II, III, IVLime rates for a Target pH of 6.5 were labeled as 1 and for
a Target pH of 6.8 were labeled as 2
Pure CaCO3 was added to the cups as prescribed by each Lab for Target pHs of 6.5 and 6.8, after converting from Lb Acre-1 to g cup-1
Soils was stirred well for homogeneity
All the sample cups were maintained at 30% moisture content for the entire duration of incubation by estimating the bulk density and pore space
The samples were weighed regularly and water was added using syringe inserted into a straw, which stayed inserted thru the incubation period, to bring the moisture content back to 30%
Preparation
Water was injected slowly into the incubating cups by a syringe inserted into a straw reaching the bottom of the cups to replace the moisture
Incubating cups were checked for any moisture loss through evaporation by weekly weighing
IncubationAll samples were kept in the dark and in a climate-controlled
area at 72°F for 63 days for incubation
Post-incubation
All the straws were removed and the soils were stirred and let them dry for a couple of days
Determined the water pH (1:2) by subsampling the cups for 20 grams of soil and adding 40 ml of water.
Sikora (Kentuky)
Huluka (Auburn)
Sikora-Moore
(Clemson)
Single titration (Georgia)
Adams-Evans (UF)
pH LR (lb/acre) pH LR
(lb/acre) pH LR (lb/acre) pH LR
(lb/acre) pH LR (lb/acre)
Bradford 5.44 1940 5.22 2258 5.21 3360 4.63 2625 5.00 2049
Clay 4.58 6099 4.30 8549 4.43 9000 3.74 12681 5.40 1570
Columbia 5.01 6007 4.98 1575 5.07 3660 4.18 2130 4.90 1845
Highlands 5.08 6007 5.00 3772 5.11 5660 4.32 4477 5.40 1698
Immokalee 4.49 6129 4.44 2312 4.56 3552 3.54 3886 5.40 2498
Lake 4.67 6007 4.49 1849 4.59 3600 3.74 2926 4.50 12652
Marion 4.83 6050 4.70 1903 4.79 3460 4.04 2014 5.25 2511
Sumter 5.04 1850 4.88 3611 5.00 5660 4.11 4736 4.95 1853
Putnam 1 3.77 1756 3.76 5373 3.83 8204 2.87 10971 4.06 4913
Putnam 2 3.89 1698 3.77 3055 3.76 5660 2.90 7126 4.09 2581
Putnam 3 4.78 1743 4.70 1950 4.78 3360 4.05 2411 4.86 1514
Jackson 4.79 1760 4.44 2204 4.51 3860 4.05 2891 4.63 1794
Lime requirement calculated for 6.5 target pH by different methods
Sikora (Kentuky)
Huluka (Auburn)
Sikora-Moore
(Clemson)
Single titration (Georgia)
Adams-Evans (UF)
pH LR (lb/acre) pH LR
(lb/acre) pH LR (lb/acre) pH LR
(lb/acre) pH LR (lb/acre)
Bradford 5.44 2292 5.22 2613 5.21 4100 4.63 3247 5.00 2353
Clay 4.58 6589 4.30 9286 4.43 9000 3.74 14445 5.40 1919
Columbia 5.01 6479 4.98 1782 5.07 4400 4.18 2501 4.90 2094
Highlands 5.08 6479 5.00 4275 5.11 6400 4.32 5327 5.40 2076
Immokalee 4.49 6612 4.44 2519 4.56 4000 3.54 4380 5.40 3055
Lake 4.67 5809 4.49 2017 4.59 4100 3.74 3332 4.50 13772
Marion 4.83 6393 4.70 2097 4.79 4200 4.04 2338 5.25 2988
Sumter 5.04 2135 4.88 4054 5.00 6400 4.11 5529 4.95 2115
Putnam 1 3.77 2024 3.76 5829 3.83 8700 2.87 12056 4.06 5251
Putnam 2 3.89 1981 3.77 3317 3.76 6300 2.90 7839 4.09 2727
Putnam 3 4.78 2015 4.70 2151 4.78 4100 4.05 2800 4.86 1709
Jackson 4.79 2048 4.44 2399 4.51 4600 4.05 3350 4.63 1979
Lime requirement calculated for 6.8 target pH by various methods
S.No Lime requirement
method
pH measured
Target 6.5 Target 6.8
1 Sikora 7.38 7.49
2 Huluka 7.49 7.55
3 Sikora-Moore 7.64 7.68
4 Single Titration 7.56 7.60
LSD (P=0.05) NS NS
Average pH values measured after lime application
County pH measured Soil texture Target 6.5 Target 6.8 OC (%) Sand (%) Silt (%) Clay(%)
Bradford 7.03 7.12 3.04 96.86 1 2.14
Clay 6.78 6.87 10.35 98.36 0 1.64
Columbia 7.82 7.83 1.43 97.36 0.5 2.14
Highlands 7.71 7.73 4.73 98.36 0 1.64
Immokalee 7.87 7.87 1.73 98.36 0 1.64
Lake 7.65 7.65 1.66 98.36 0 1.64
Marion 7.82 7.88 1.76 98.36 0 1.64
Sumter 7.37 7.5 3.78 98.36 0 1.64
Putnam 1 7.37 7.49 5.20 98.36 0 1.64
Putnam 2 7.67 7.71 1.86 98.36 0 1.64
Putnam 3 7.38 7.52 1.35 98.36 0 1.64
Jackson 7.71 7.75 1.94 89.36 7 3.64
LSD (0.05%) 0.95 0.78
Average target pH values measured in various county samples
Take home messagesAll the methods have over-estimated the lime requirements
as indicated by the increase in pH beyond the Target pH at the end of the incubation period
Differentials in Target pHs were not realized even with different lime recommendation amounts, for any of the methods
Soil pH determinations showed a high amount of variation, with possible statistical significance in certain cases
Other soil physical and chemical parameters may be influencing the lime efficacy
Field calibrations may further increase the variability