Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity,...
Transcript of Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity,...
![Page 1: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/1.jpg)
Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition
Neil Miles
Fertasa Soil Acidity WorkshopMay 2019
AcknowledgementsMart Farina, Guy Thibaud, Alan Manson
![Page 2: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/2.jpg)
Mart Farina
Is soil acidity a serious problem? Yes…..and no!
![Page 3: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/3.jpg)
Is soil acidity a serious problem?
Yes…..and no!
![Page 4: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/4.jpg)
ARC - Soil, Climate and Water
![Page 5: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/5.jpg)
This presentation .…
1. What, precisely, is the problem?
2. Impact on plant growth
3. Correction
![Page 6: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/6.jpg)
Causes of soil acidity• Natural:
➢high rainfall (leaching of bases) over long time periods (older land surfaces)
➢more rapid in well drained sandsthan in moderately and poorly-drained loams and clays
• Man-induced:➢ammonium fertilizers➢ removal of nutrients in harvests and
by animals (milk & meat)➢ tillage (oxidation of organic matter)➢ industrial pollution➢ forestry
![Page 7: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/7.jpg)
Most plants can grow at very low pH in nutrient solution
culture!…so what exactly is
the problem ?
![Page 8: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/8.jpg)
![Page 9: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/9.jpg)
![Page 10: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/10.jpg)
![Page 11: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/11.jpg)
![Page 12: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/12.jpg)
![Page 13: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/13.jpg)
![Page 14: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/14.jpg)
Aluminium as the primary factor in soil acidity effects on plant growth….
• First reported in 1918 (Hartwell and Pember, 1918. Soil Science)
• But…Beckman’s breakthrough (1934) with pH electrode technology detracted from further Al research!
• Role of Al ‘rediscovered’ by Reeve & Sumner (South Africa) and Kamprath (USA) in the 1970’s.
• Superiority of Al saturation as an index of soil acidity highlighted in field trials of Farina (1970 – 1990).
• Brazilian work from 1970’s to date – similar findings.
• Australian research on wheat confirmed that Al superior to pH as a predicative index.
![Page 15: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/15.jpg)
Diagnostic criteria using soil tests
Ratio of exchangeable Al to total cations (a convenient ‘proxy’ for Al activity) most reliable
predictor
Al+HCa + Mg + K + Al+H
Acid Sat % = X 100
![Page 16: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/16.jpg)
What about manganese toxicity?A frequent problem in soils that are not inherently
acidic following acidification by agricultural practices!
![Page 17: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/17.jpg)
Manganese Toxicity
➢Less widespread than Al toxicity.
➢May occur at higher pH’s than Al toxicity.
➢Usually not a problem on highly weathered, naturally acidic soils (Mn leached out!)
Dr Mart Farina
![Page 18: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/18.jpg)
Mn toxicity - most severe under reducing conditions created by water-logging
and compaction
![Page 19: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/19.jpg)
0
10
20
30
40
50
60
4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0
Mn
(m
g/L
)
pH (CaCl2)
Pongola sugarcane topsoils: pH vs manganese
![Page 20: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/20.jpg)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0
10
20
30
40
50
60
4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0
Al+
H (
cmo
l c/L
)
Mn
(m
g/L
)
pH (CaCl2)
Pongola and Inanda topsoils
Mn
Al + H
![Page 21: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/21.jpg)
2. Effects of acidity factors on plant growth
![Page 22: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/22.jpg)
lucerne / white clover
perennial ryegrass
Eragrostis curvula
kikuyu
tall fescue
Italian ryegrass
Digitaria eriantha, oats
cocksfoot
highly
sensitive
highly
tolerant
red clover, barleymoderately
sensitive
moderately
tolerant
sunflower
dry bean, cotton
sorghum
maize, lupin
soyabean
potato
sweet potato
cow pea
sugar cane
Pastures Crops
![Page 23: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/23.jpg)
Dr Mart Farina
Major problem: accelerated acidification in already affected areas
due to very poor N uptake
![Page 24: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/24.jpg)
![Page 25: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/25.jpg)
![Page 26: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/26.jpg)
Mart Farina
![Page 27: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/27.jpg)
0
10
20
30
40
50
60
70
80
3.0 3.5 4.0 4.5 5.0D
ep
th (
cm)
pH (CaCl2)
pH
0
10
20
30
40
50
60
70
80
20 40 60 80 100
De
pth
(cm
)
Acid Sat %
Acid Sat
![Page 28: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/28.jpg)
No lime
6 t/ha lime
![Page 29: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/29.jpg)
![Page 30: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/30.jpg)
![Page 31: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/31.jpg)
![Page 32: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/32.jpg)
![Page 33: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/33.jpg)
![Page 34: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/34.jpg)
![Page 35: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/35.jpg)
No definite info on acid tolerances of many cover crop species. So in mixed species pasture, wise option is to
target zero acid sat!
![Page 36: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/36.jpg)
Acid sat = 46%
Acid sat = 30%
Gavin Moore
![Page 37: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/37.jpg)
lucerne, cabbage,
tobacco, potato,
pineapple, beans
carrot, white lupin
Highly
sensitive
Highly
tolerant
Moderately
sensitive
Moderately
tolerant
soyabean, peanuts
wheatTentative ranking of tolerances to excess
Manganese (based on literature
reports)Note: large cultivar differences occur
barley
maize
cotton
sweet potato
sunflower
![Page 38: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/38.jpg)
Mart Farina
![Page 39: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/39.jpg)
Manganese Toxicity
Localized accumulation of Mn
Mart Farina
![Page 40: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/40.jpg)
Mn-induced iron deficiency
Mart Farina
Manganese Toxicity
![Page 41: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/41.jpg)
3. Correction of soil acidity problems
1. Roles of lime and gypsum
2. ‘Alternative and new’ products
![Page 42: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/42.jpg)
LIME GYPSUM(Calcitic or Dolomitic)
![Page 43: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/43.jpg)
+ MOISTURE
![Page 44: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/44.jpg)
+ MOISTURE
![Page 45: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/45.jpg)
0
10
20
30
40
50
60
70
3.5 4.0 4.5 5.0 5.5 6.0
Aci
d S
at
%
pH(KCl)
Relationship between pH (KCl) and acid saturation(Hutton soil - Cedara)
+ lime
Lime:- increase pH- neutralizes Al
![Page 46: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/46.jpg)
4
6
8
10
12
14
16
18
4.0 4.5 5.0 5.5 6.0
ECEC
(cm
ol/
L)
pH (CaCl2)
Variation in ECEC with pH in a Griffin soil (60% clay)
![Page 47: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/47.jpg)
0
100
200
300
400
500
600
700
800
900
1000
3.5 4.0 4.5 5.0 5.5 6.0
Ca
lciu
m (
mg
/L)
pH(KCl)
Relationship between pH (KCl) and soil calcium(Hutton soil - Cedara)
0
50
100
150
200
250
300
350
400
450
3.5 4.0 4.5 5.0 5.5 6.0
Ma
gn
esi
um
(m
g/L
)
pH(KCl)
Relationship between pH (KCl) and soil magnesium(Hutton soil - Cedara)
![Page 48: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/48.jpg)
Nutrient availability and soil pH
4 5 6 7 8 9
Nu
trie
nt
avail
ab
ilit
y t
o c
rop
Soil pHw
CalciumMagnesium
Molybdenum
Zinc, CopperManganese, Iron
![Page 49: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/49.jpg)
Important lime requirement considerations
• Lime quality (physical and chemical)
• Soil buffering (clay and organic matter contents)
• Depth of incorporation
• Crop species requirement
![Page 50: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/50.jpg)
4.0
4.5
5.0
5.5
6.0
6.5
7.0
0 5 10 15 20 25
So
il p
H (
KC
l)
Lime rate (t/ha)
Balmoral (70% clay)
Griffin (33% clay)
Avalon(10% clay)
Variable soil response to liming (buffering capacity effects)
Importantly – if soil pH kept above about 4.5KCl or 5.5H20, Al toxicity cannot occur.
![Page 51: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/51.jpg)
Economics of soil acidity correction
Significant increases in sugarcane yields in Australia
were still being recorded 18 years after a single
application of 5 t/ha of lime, which resulted in
approximately 366 t of additional cane relative to the
unlimed treatment over the 18 year period!
(Noble and Hurney, 2000)
R146 400
R3 500
= R4083% return(227% /yr)
![Page 52: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/52.jpg)
‘Enhanced efficiency’ liming and gypsum products
➢Granular
➢Liquid
➢Microfine
![Page 53: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/53.jpg)
Micro-fine liquid and pelletized (granular) limes
Frequent claims
• Faster reaction
• Application advantages
• Mobile through the soil profile
• Vastly lower rates have the same effect as tons of conventional lime on pH etc
• Ca highly available relative to conventional limes
X
X
X
![Page 54: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/54.jpg)
Evidence is that lime granules remain intact in the soil for very long
periods after application.
Stuart Brill
![Page 55: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/55.jpg)
Pelletized / granular lime research reports….
Reference Conclusions
Lollato et al., 2013 Soil Sci Soc Amer J.
• pellets intact more than 220 d after application
• failed to significantly increase soil pH• failed to decrease soil Al
Murdock, 1997. Univ of Kentucky
Pelletized lime reacts no faster than conventional lime.
Damon et al.,2018. Australia
Pelletized lime: no effect on pH and Al
Dreyer, unpublished report, NW University, SA
• granular not as effective at increasing soil pH as conventional lime.
• granular not mobile. • granules undissolved after 3.5 months in
moist acid soil.
![Page 56: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/56.jpg)
Worrying: the naïve (dishonest?) marketing approaches frequently used…
1. Dairy farmer, KZN: use granular lime at ¼ rate as substitute for conventional lime!
2. Maize/soya farmer in Mpumalanga: limed to zero acid sat, spent R200000 on granular lime ‘to supply Ca’.
3. Sugarcane farmer in Komati: soil Ca levels of 4000 ppm, supplying liquid lime through drippers ‘to correct Ca deficiency…’ (Clogged drippers..!!!)
![Page 57: Principles of Soil Acidity, Liming, Calcium and …...2019/05/01 · Principles of Soil Acidity, Liming, Calcium and Magnesium Nutrition Neil Miles Fertasa Soil Acidity Workshop May](https://reader030.fdocuments.us/reader030/viewer/2022040408/5eb7dacd7e5c71274d3b279f/html5/thumbnails/57.jpg)
Concluding thoughts
Soil Acidity …..serious or not?
• Serious? Yes, impact on yields can range from moderate to devastating
BUT
• Cause: well known and understood
• Diagnosis: easy and reliable (soil tests)
• Correction: highly effective correction with mostly natural and benign products
• Economics of correction: generally highly favourable