Transcript Efficient Management of Micronutrients in Rice

Efficient Management of Micronutrients
in Rice
K. V. Rao
Principal Scientist (Soil Science)
Directorate of Rice Research
Fertilizer nutrient consumption
and balance in Indian Agriculture
Year
Fertilizer consumption (M. tons)
N
P2O5
K2O
Total
1951
0.065
1999 11.6
4.8
1.7
18.1
2020 20.74
6.77
2.06
29.07
Crop uptake (M. tons)
2020
11.87
5.27
20.32
37.46
Deficit +8.9
+1.5
-18.3
-8.3
Zone wise consumption ratio of nutrients (NPK)
2007-2008
Zone
N
P2O5
K2O
Total (kg/ha)
North
East
West
South
All India
17.5
4.1
5.1
2.8
5.5
3.9
1.6
2.6
1.4
2.1
1
1
1
1
1
161.5
103.5
82.5
154.9
117
Emerging Nutrient Deficiencies
Elements deficient
Foodgrain production (Mt)
400
N
Fe
N
K
P
Zn
Fe
N
Mn
S
K
P
Zn
Fe
N
B
Mn
S
K
P
Zn
Fe
N
B
Mn
S
K
P
Zn
Fe
N
1950
1960
1970
1980
1990
2000
Mo
B
Mn
S
K
P
Zn
Fe
N
300
250
200
150
100
50
0
2010
2025
Foodgrain production
350
?
Mo
B
Mn
S
K
P
Zn
Fe
N
Critical limits and extent of
deficiency in Indian soils
Nut Critical Extent of
rlimits
def. (%
ient (ppm) samples)
S
10
41
Zn
0.6
49
Fe
4.5
12
Cu
Mn
0.2
2.5
3
4.4
B
0.5
32
Deficiency of Boron in Indian soils
State/soil
% Deficiency
Bihar
West Bengal
Karnataka
UP
MP
TN
Punjab
Gujarat
Haryana
India
Red & laterites
39.0
68.0
32.0
24.5
22.5
21.0
13.0
2.0
1.5
33.0
37-68
Deficiency of Sulfur in different states
State
Bihar
Rajasthan
Kerala
Karnataka
HP
Orissa
UP
MP
TN
Punjab
Gujarat
Haryana
India
% Deficiency
28.0
23.0
33.0
34.0
43.0
51.0
62.0
40.0
36.0
26.0
38.0
35.0
41.0
Acidic
Non acidic
Percent samples deficient
60
50
40
30
20
10
0
Zn
Cu
Fe
Mn
B
Extent of micronutrient deficienies in soils of India
Mo
Soil/water resources and rice production
 Rice production demand by 2025 ~ 125 Mt
 Rice is cultivated in > 44 M. ha of variety (15) of soils; and
consume > 50% of irrigation water; 38-40% of fertilizers; and
17-18% of pesticides
 About 8M.ha of rice soils are deficient in Zn, and is most
preferred crop in salt affected soils (> 8M.ha)
 About 15 M ha of rice soils are acidic associated with Fe
or Al toxicity, depletion of bases (Ca, K, Mg), P fixation and
likely deficiency of B, Si
 Blanket fertilizer management over large domains
 Stagnation/ deceleration in productivity growth, and changing
pest and disease intensity
 Major nutrient problems observed in rice are –
Deficiency N, P, Zn, Fe, S, K, Mn, Ca, B, Si and
Toxicity Fe, H2S, Al, B, As, Se
Zn deficiency in rice
 It is widely spread in calcareous, clayey-neutral, saline-sodic,
coarse-textured, highly weathered and leached soils in
Bihar, Karnataka, AP, Punjab, Haryana, UP, Tamil Nadu,
orissa, Maharashtra, and Madhya Pradesh,
 Uneven plant growth in patches and stunted, earliness, low
spike let no. and yield.
 Brown to dusty brown spots on younger leaves in red soils,
yellowing of leaves /midrib bleaching in black soils
appearing at 2–4 WAT.
ZINC MANAGEMENT








Regular application of OM (FYM, PM, BG slurry, Compost) @ 510 t /ha helps mitigate deficiencies of all micronutrients
Drain the fields frequently with good quality irrigation water
Normal soils- Apply 5.5 -11.0 kg Zn /ha for every 3 seasons
preferably in rabi season in soils with < 0.3-0.5 ppm Zn in
sandy and clay soils, respectively
Sodic soils / Brackish ground water - 22 kg Zn / ha initially
followed by 5-10 kg Zn in the later years or 50% gypsum + 10 t
GM + 22 kg Zn once in 2-3 years
Seed treatment or root dipping in 2.0% ZnO suspension in
moderate Zn deficient soils
Mid season correction -Spraying 0.5% ZnSO4 thrice at weekly
intervals between 3-6 WAT
Grow Zn efficient and tolerant varieties- Vikas, Rasi, Hybrids etc
Response of crops to zinc fertilization in India
Crop
Individual expt.
Mean of expt.
Av.
Resp.
t ha-1
2447
1652
280
0.00-4.70
0.00-5.47
0.01-3.09
0.01-1.47
0.14-1.27
0.11-1.37
0.42
0.54
0.47
Sorghum
Soybean
Onion
Potato
83
12
3
45
0.07-1.35
0.08-0.69
1.36-8.70
0.10-7.60
0.21-0.65
0.16-0.39
1.70-4.91
2.40-3.90
0.36
0.36
5.13
3.0
Sugarcane
6
8.00-4.30
1.72-2.40
3.8
Wheat
Rice
Maize
No. of
Expts.
Range of response t ha-1
Source: M.V. Singh (1997, 1999a), AICRP Micronutrients , IISS, Bhopal
Effect of zinc and gypsum application
on yield of rice in sodic soils(t/ha)
ZnSO4
(kg/ha)
Gypsum levels (t/ha)
Mean
0
0
0.13
2.5
0.98
5.0
2.14
10.0
2.65
1.48
10
0.49
1.87
3.06
3.77
2.30
20
0.58
2.00
3.14
3.85
2.39
30
0.68
1.75
2.99
3.92
2.34
40
1.05
2.02
3.29
3.89
2.56
Mean
0.59
1.72
2.93
3.62
-
LSD
(0.05)
Gypsum 0.36;
ZnSO4 0.28
Iron Deficiency in rice
Fe deficient upland rice
Interveinal chlorosis of emerging leaves,
whole leaves becoming chlorotic and
turns very pale. Plants become stunted
with narrow leaves.
Fe deficiency is serious constraint to rice in uplands in neutral, alkaline
and calcareous soils, in coarse textured low organic matter soils, in
alkaline and calcareous low lands, and under excessive concentrations
of Mn, Cu, Zn, Al and nitrates in root zone.
Management of Fe deficiency
Sources Ferrous sulphate (19-20.5%Fe), Fe-EDTA (9-12%Fe), FeEDDHA (10% Fe), besides organic manures (FYM 0.15%
Fe), poultry and piggery manure (0.16% Fe), sewage
sludge are used as sources for correcting Fe chlorosis.
 Seed treatment with 2% FeSO4.7H2O solution/slurry.
 Foliar sprays (2-3) of 1-2% FeSO4.7H2O/FeNH4SO4 (pH
5.2) solution or of chelates at weekly interval at
early stage of deficiency are successful.
 Combination of green manure (GM) or organic manures
with foliar spray of un-neutralized 1%FeSO4.7H20
/FeNH4SO4 (pH 5.2) solution
Sulfur Nutrition in Rice
Rice field showing S deficiency symptoms
Reduced plant height and
tillering
Chlorosis of young leaves
and necrosis of tips
 Soils with low organic matter status,
highly weathered ,containing large
amounts of Fe oxides, sandy soils are
deficient in S supply.
 About 3-5 kg S is removed by rice per ton
of grain. Apply 30-40 kg/ha S through
gypsum, phospho-gypsum, ammonium
sulphate, elemental S etc.,
Boron deficiency in rice
B deficiency occurs in highly weathered, acid upland, coarse
textured sandy soils, acid soils derived from igneous rocks, and
in soils of high organic matter and calcareousness
 B availability is reduced under moisture stress and dry
conditions
 B deficiency symptoms usually appear first on young leaves.
Reduced plant height and the tips of emerging leaves are white
and rolled
 Rice plants fail to produce panicles if they are affected by B
deficiency at the panicle formation stage

Management of Boron deficiency
 Borax, granubor & boric acid are efficient sources
 Basal soil application of B (1-2 Kg B / ha) is superior to foliar
sprays. Soil application has residual effect for 1-2 seasons
 For hidden deficiency spray 0. 2% boric acid or borax at pre
flowering or flower head formation stages
 AICRIP results show increased grain number (25-45), filled spike
lets and significant increase in grain yield by 4-8% of cultures
IET 20979, IET 21007 and IET 21014.
520
510
500
Influence
of
Boron
application on rice yield
(g/sq.m) (11 locations,
AICRIP, 2009)
490
480
470
460
Control
0.2 ppm
0.4 ppm
0.8 ppm
Manganese deficiency in rice wheat system
 Manganese deficiency in rice is sporadic and increasing in wheat in Punjab in R-W
system (after 7-10 years) in highly permeable alkaline soils low in OM
 Also in highly degraded, acid sulfate and acid upland soils, and alkaline / calcareous
soils with low OM and reducible Mn
 Symptoms on rice are pale grayish green interveinal chlorosis from tip to base of
young leaves with necrotic brown spots developing later.
Management
Soil application - MnSO4.4H2O @ 40-50 kg/ha (less economical)
Foliar spray 3-4 times @ 0.5-1.0% MnSO4 solution (5-15 kg Mn /ha) at tillering stage in
about 200 L water per ha.
Durum wheat more susceptible than aestivum wheat.
 Apply farmyard manure or straw incorporation
 Chelates are less effective because Fe and Cu displace Mn.
Residual response (kg/ha) to secondary and
micro- nutrient applied in rice under RWCS
Site
S
Zn
B
Mn
Cu
Ranchi
Modipuram
Kanpur
R.S. Pura
Pantnagar
Ludhiana
Average
48
1350
511
191
505
167
462
48
960
286
183
90
313
580
471
96
382
600
57
36
231
277
119
173
PDCSR and IPNI Research, Modipuram
Approved micronutrient fertilizers under FCO
Materials
Element/Forms
Content (%)
Zinc sulphate.
Zn
21.0
Manganese Sulphate*
Mn
30.5
Ammonium Molybdate
Mo
52.0
Borax (For soil application)
B
10.5
Solubor (Foliar spray)
B
19.0
Copper Sulphate*
Cu
24.0
Ferrous & Ferric
19.0 & 0.50
Zn
33.0
Zn + P
19.5
Chelated Zn (EDTA form)
Zn
12.0
Chelated Fe (EDTA form)
Fe
12.0
B+P2O5
0.18B +16.0
Zn+N
2.0 Zn + 43.0 N
Ferrous sulfate
Zinc Sulphate mono-hydrate
Zinc Phosphate Zn3(PO4)2.4H2O
Boronated super phosphate
Zincated urea
*S % in ZnSO4.7H2O-15%, MnSO4.4H2O -17%, CuSO4.5H2O-13%, FeSO4.7H2O-19%
Iron toxicity in rice
 Tiny brown spots from tips to leaf base of older leaves, reddish
brown, purplish bronzing, yellow orange discoloration
 Commonly observed at maximum tillering / heading stage
 Reduces yields by12-100%.
 Reported in Orissa (42%), West Bengal, Chattisgarh, Jharkhand,
Kerala, NE and NW hills, HP, Karnataka, North costal AP, in acid
and acid sulfate soils rich in reducible iron, light textured,
moderate to high SOM, and low CEC.
Management of Fe toxicity
 Plant rice tolerant varieties (e.g., Mahsuri, Phalguna,
MTU 1010, IET 20550).
Seed treatment (DSR) with Ca peroxide @ 50–100%
seed wt.
Delaying planting until peak in Fe2+ concentration has
passed (> 10–20 DAF)
 Intermittent irrigation and midseason drainage at
mid-tillering stage (25–30 DAT/DAS),
Balanced use of fertilizers (NPK or NPK + lime),
additional K, P, and Mg fertilizers.
Sulfide toxicity
 S toxicity occurs in degraded, low active Fe status, poorly drained
organic soils, acid- sulfate soils.
 Deficiency of K and unbalanced crop nutrient status, excessive
application of urban or industrial sewage aggravate sulfide toxicity
Symptoms
 Reduced nutrient uptake due to decreased root respiration
 Interveinal chlorosis of emerging leaves, coarse, sparse, and
blackened roots,
 Toxicity occurs at >0.07 mg H2S per L in soil solution
Management
 Midseason drainage at mid tillering stage (25–30 DAT/DAS),
 Avoiding flooding and maintain moist conditions for 7–10 days
 Apply K, P, lime and Mg fertilizers, and Fe (salts, oxides) to
immobilize H2S .
 Avoid large quantities of organic matter application
 Dry plough field after harvest to oxidize S and Fe
Aluminium toxicity
Symptoms




Orange-yellow
interveinal
chlorosis of younger leaves
Poor growth stunted plants
Yellow to white mottling of
interveins, followed by leaf tip
death and leaf margin scorch
Necrosis of chlorotic areas
occurs if Al toxicity is severe
Occurrence


Al toxicity is major constraint in
acid upland soils of pH <5.2 with
large exchangeable Al content
in NEH, Jharkhand, WB, Assam,
Acid sulfate soils when grown
as upland crop few weeks
before flooding
Al toxicity management
 Planting tolerant cultivars which accumulate less Al and
absorb Ca and P efficiently e.g. IR43,CO37 and Basmati
370
 Liming of soil with CaCO3 preferably dolomite lime to
supply Mg @ 2-4 t/ha to neutralize soil acidity and
replace exchangeable Al.
 Correct sub soil acidity by leaching soluble source of Ca
like gypsum / phosphogypsum / SSP / lime
 Incorporate 1 t/ha of reactive rock phosphate to supply P
 Planting Al-tolerant cultivars such as IR43, CO 37, and
Basmati 370 which complex soluble Al by root
exhudates and accumulate P, Mg and Ca
 Soil mulching and / or green manuring / organic
manuring prevents water loss and phytotoxicity
Boron toxicity
Occurs in arid and semi arid regions, high in
temperature, in volcanic soils
Use of B-rich groundwater, sewage and
municipal wastes or borax
Critical toxicity limits of B in soils - > 4 mg/
kg (0.05N HCl) or > 5 mg B per kg (hotwater soluble B) or > 2 mg B per L in
irrigation water.
Symptoms
Plants show brownish leaf tips and dark
brown elliptical spots on leaves
Management
Deep plowing during off season and
leaching, use of surface water with low B
content or dilution, Growing tolerant
varieties like IR42, IR46, IR48, IR54,
Si deficiency
Rice absorbs ~100 kg Si per ton of grain.
Si-deficient plants are susceptible to lodging with soft, droopy
leaves and culms, Lower leaves with yellow / brown necrotic,
 Critical concentration for Si - 40 mg Si per kg soil (1 M Na acetate
4.0 pH)
Si deficiency occurs in old and strongly weathered, leached acid
soils, and due to removal of rice straw , excessive use of N.
Si deficiency is not yet common in intensive irrigated rice systems
of tropical Asia.
Management of Si deficiency
 Recycling rice straw (5–6% Si), and rice husks (10%), applying rice
hull ash and balanced nutrient use of NPK
 Apply granular silicate fertilizers for rapid correction- Ca silicate:
120–200 kg/ha; K silicate: 40–60 kg/ha
 Apply basic slag @2-3 t/ha once in two years, or fly ash (23% Si)
use is beneficial
 Foliar spray Si @0.1-0.2% with sodium silicate improve Si nutrition
Efficient genotypes for nutrient
stress situation
Stress
Genotypes
Low N
Low P
Swarna, Sarjoo-52, Bejhary, Pranava,
Salivahana
Rasi, RPA 5929, MTU 2400, Vikramarya
Low Zn
CSR 10, Sarjoo-52, Vikas, IR-30864
Fe toxicity
Mahsuri, Phalguna, Dhanrasi
Low nutrient use efficiency in rice
Nutrient
Efficiency (%)
N
30-40
P
15-20
K
40-50
Zn
2-5
Fe
1-2
S
20-25
Distribution of Sulphur Deficiency (240 Districts)
A
B
C
A- 45% Districts having > 40% soil samples deficient in S
B- 40% Districts having 20-40% soil samples deficient in S
C- 15% Districts having < 20% soil samples deficient in S
Micronutrient
B
AVAILABILITY INDICES FOR
MICRONUTRIENTS
Indices
Hot water soluble
Critical level (ppm)
Range
Mean
0.1-2.0
0.7
Cu
Mehilch No.1
DTPA + CaCl2 (pH 7.3)
AB-DTPA (pH 7.6)
0.1-10
0.12-2.5
3.0
0.8
1.8
Fe
DTPA + CaCl2 (pH 7.3)
AB-DTPA (pH 7.6)
2.4-5.0
4.0
4.0
Mn
Mehilch No.1
DTPA + CaCl2 (pH 7.3)
0.03 M H3PO4
AB-DTPA (pH 7.6)
4-8
1.0-2.0
0-20
7.0
1.4
10
1.8
Mo
(NH4)2C2O4 (pH 3.3)
0.04-0.2
-
Zn
0.1N HCl
Mehlich No.1
DTPA + CaCl2 (pH 7.3)
AB-DTPA (pH 7.6)
2.0-10.0
0.5-3.0
0.25-2.0
5
1.1
0.8
1.5
Major management-related
concerns in Agricultural Production
 Increasing
food demand >300 Mt. by 2025; Rice -
>130 Mt
 Low and imbalanced use of fertilizers and OM negative balance, soil nutrient depletion, low NUE
and declining soil quality
 Blanket fertilizer management over large domains
 Increasing area under water and management
induced soil degradation
 Stagnation/ deceleration in productivity growth in
intensive rice crop systems
 Changing pest and disease intensity and scenario