Efficient Management of Micronutrients in Rice

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Efficient Management of Micronutrients in Rice

• K. V. Rao
• Principal Scientist (Soil Science)
• Directorate of Rice Research

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Fertilizer nutrient consumption and balance in
Indian Agriculture
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Zone wise consumption ratio of nutrients
(NPK)2007-2008
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Emerging Nutrient Deficiencies
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Critical limits and extent of deficiency in
Indian soils
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Deficiency of Boron in Indian soils
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Deficiency of Sulfur in different states
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(No Transcript)
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Soil/water resources and rice production

• Rice production demand by 2025 125 Mt
• Rice is cultivated in gt 44 M. ha of variety
  (15) of soils and
• consume gt 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 (gt
  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

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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 24 WAT.

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ZINC MANAGEMENT

• Regular application of OM (FYM, PM, BG slurry,
  Compost) _at_ 5-10 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 lt
  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

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Response of crops to zinc fertilization in India
Source M.V. Singh (1997, 1999a), AICRP
Micronutrients , IISS, Bhopal
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Effect of zinc and gypsum application on yield of
rice in sodic soils(t/ha)
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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.
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• Management of Fe deficiency
• Sources-
• Ferrous sulphate (19-20.5Fe), Fe-EDTA
  (9-12Fe), Fe-
• EDDHA (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
  1FeSO4.7H20
• /FeNH4SO4 (pH 5.2) solution

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Sulfur Nutrition in Rice
Rice field showing S deficiency symptoms
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.,

Reduced plant height and tillering
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• 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

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• 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.

Influence of Boron application on rice yield
(g/sq.m) (11 locations, AICRIP, 2009)
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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 _at_ 40-50 kg/ha (less
  economical)
• Foliar spray 3-4 times _at_ 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.

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Residual response (kg/ha) to secondary and micro-
nutrient applied in rice under RWCS
PDCSR and IPNI Research, Modipuram
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Approved micronutrient fertilizers under FCO
S in ZnSO4.7H2O-15, MnSO4.4H2O -17,
CuSO4.5H2O-13, FeSO4.7H2O-19
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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.

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• Management of Fe toxicity
• Plant rice tolerant varieties (e.g., Mahsuri,
  Phalguna,
• MTU 1010, IET 20550).
• Seed treatment (DSR) with Ca peroxide _at_ 50100
• seed wt.
• Delaying planting until peak in Fe2
  concentration has
• passed (gt 1020 DAF)
• Intermittent irrigation and midseason drainage
  at
• mid-tillering stage (2530 DAT/DAS),
• Balanced use of fertilizers (NPK or NPK lime),
• additional K, P, and Mg fertilizers.

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• 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 gt0.07 mg H2S per L in
  soil solution
• Management
• Midseason drainage at mid tillering stage
  (2530 DAT/DAS),
• Avoiding flooding and maintain moist
  conditions for 710 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

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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 lt5.2 with large exchangeable Al
  content in NEH, Jharkhand, WB, Assam,
• Acid sulfate soils when grown as upland crop few
  weeks before flooding

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• 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 _at_ 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

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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 - gt 4 mg/ kg (0.05N HCl) or gt 5 mg B per
kg (hot-water soluble B) or gt 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,
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• 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 (56 Si), and rice husks
  (10), applying rice
• hull ash and balanced nutrient use of NPK
• Apply granular silicate fertilizers for rapid
  correction- Ca silicate
• 120200 kg/ha K silicate 4060 kg/ha
• Apply basic slag _at_2-3 t/ha once in two years, or
  fly ash (23 Si)
• use is beneficial
• Foliar spray Si _at_0.1-0.2 with sodium silicate
  improve Si nutrition

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Efficient genotypes for nutrient stress situation
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Thank You
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Low nutrient use efficiency in rice
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Distribution of Sulphur Deficiency (240
Districts)
A- 45 Districts having gt 40 soil samples
deficient in S B- 40 Districts having 20-40
soil samples deficient in S C- 15 Districts
having lt 20 soil samples deficient in S
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AVAILABILITY INDICES FOR MICRONUTRIENTS
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Major management-related concerns in Agricultural
Production

• Increasing food demand gt300 Mt. by 2025 Rice -
  gt130 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