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Drought and its mitigation strategies in agriculture SEMINAR on COLLEGE OF AGRICULTURE, DEPARTMENT OF AGRONOMY PRESENTED BY: Soumya Ranjan Bhuyan I.D No.-160111022 MAJOR ADVISOR Dr. Manish Bhan Asst. Professor Agronomy SEMINAR INCHARGE Dr.M.L Kewat Professor,Agronomy

Soumya drought and its mitigation

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Page 1: Soumya drought and its mitigation

Drought and its mitigation strategies

in agriculture

SEMINAR

on

COLLEGE OF AGRICULTURE, DEPARTMENT OF AGRONOMY

PRESENTED BY:Soumya Ranjan BhuyanI.D No.-160111022

MAJOR ADVISORDr. Manish BhanAsst. ProfessorAgronomy

SEMINAR INCHARGEDr.M.L KewatProfessor,Agronomy

Page 2: Soumya drought and its mitigation

Sequence of presentation

Introduction

Concept of drought

Mitigation techniques

Mitigation through crop management practices

Soil and water conservation techniques

Conclusion

Page 3: Soumya drought and its mitigation

INTRODUCTION

INTRODUCTION

Page 4: Soumya drought and its mitigation

Source-NICRA,2014

Page 5: Soumya drought and its mitigation
Page 6: Soumya drought and its mitigation

Drought is a situation when the actual seasonal rainfall is deficient

by more than twice the mean deviation (Ramdas,1960)

Drought is defined by deviation from the normal rainfall, it can

happen in all rainfall regions. It also occurs in high rainfall area

but severity or frequency may vary.

Drought is considered to be a strictly meteorological phenomenon.

It is also a complex phenomenon whose severity depends on the

precipitation amount, its time and space distribution, evapo-

transpiration and on hydrological factors.

Definition

Page 7: Soumya drought and its mitigation

Classification of drought

Meteorological drought: It is defined as a situation when there is a25% decrease in average rainfall for a given period oftime(IMD,Pune)

Hydrological drought: Depletion of surface water and consequentlydrying of reservoirs, tanks etc. It results in deficiency of water forall sectors using water.

Agricultural drought: It is the result of soil moisture stress due toimbalance between available soil moisture and evapotranspirationdemand of a crop.

Socio-economic drought: This is associated with the supply &demand of some economic goods. This drought should be linkedhot only to precipitation but also trends of fluctuations in demand.

Page 8: Soumya drought and its mitigation

Classification of drought

Meteorological drought

Hydrological drought

Agricultural drought

Page 9: Soumya drought and its mitigation

o Shortage of water

o Desertification

o Death of livestock

o Lack of water for irrigation

o Reduced crop yield

o Migration of people

o Scarcity of seed

Consequence of drought

Page 10: Soumya drought and its mitigation

Effects of drought on plants

o Loss of turgidity

o Photosynthesis

o Increase in number of stomata

o ABA accumulation

o Rolling and wilting of leaves

o Reduced tillering

o Forced maturity

o Reduction in productivity

Page 11: Soumya drought and its mitigation

Table 1: Economic yield reduction by drought stress in some

representative field crops

Crop Growth stage Yield reduction

Barley Seed filling 49 – 57%

Maize Grain filling 79 – 81%

Maize Reproductive 63 – 87%

Maize Vegetative 25 – 60%

Rice Reproductive (severe stress)53 – 92%

Dryland farming - Crops and Techniques for Arid Regions

-R. Crosswell and F.W. Martin

Page 12: Soumya drought and its mitigation

Drought stress resistance mechanism in plants

Plants optimize the morphology, physiology and metabolism of

their organs and cells.

The reactions of the plants to water stress differs significantly at

various organizational levels depending upon intensity and

duration of stress as well as plant species and its stage of

development

Page 13: Soumya drought and its mitigation

Adaptations

Drought escape Drought resistance

Drought toleranceDrought avoidance

Water conservation More water uptake

Mitigating drought High tolerance to drought

Principles of agronomy Yellamanda Reddy and Shankara Reddy

Page 14: Soumya drought and its mitigation

Stress avoidance : is the ability of plant to maintain high tissue water

potential under drought conditions.

Stress tolerance : is a plant’s stability to maintain its normal

functions even at low tissue water potentials.

Stress resistance

Stress

tolerance

Stress

avoidance

Page 15: Soumya drought and its mitigation

Stress avoidance is usually achieved through morphological

changes in the plant :

Reduced stomatal conductance

Decreased leaf area

Development of extensive root systems

Increased root/shoot ratios

Stress tolerance is achieved by mitigating stress and high

degree of tolerance by plants.

Page 16: Soumya drought and its mitigation

Mitigation strategies

Mitigation of Stress by Crop

Management

Soil and moisture conservation

measures

Page 17: Soumya drought and its mitigation

Mitigation by crop management practices

Selection of crops/varieties

Seed hardening

Sowing of crops

Page 18: Soumya drought and its mitigation

Selection of crops/varieties

Short duration

Early vigour

Deep root system

Dwarf plant with erect leaves and stems

Moderate tillering

Lesser period between flowering and maturity

Moderate dormancy

Wider adoptability

Source-Venketeshwarlu,2009.Indian Journal of Agricultural Science

Page 19: Soumya drought and its mitigation

Relative drought tolerant crops

RABI KHARIF LEGUMES

• Oats• Barley• Triticale

• Sorghum• Pearl millet• Kodo millet• Green gram• Black gram• Niger

•Soybean•Groundnut•Chickpea•Cowpea•Pigeon pea

Page 20: Soumya drought and its mitigation

• Pearl millet: CZIC 923,HHB 67,HHB 68,GHB 183,GHB 1399,etc

• Cluster bean: Maru guar, FS 277,HG 75, HG182,I-IGS 365,RGC 936, PLG119, PLG 85,Suvidha, Navcen,etc

• Mung bean: Asha,K 851,RMG 131,etc

• Moth bean: RMO 40,Marp moth,Jadia,Jawala,PCMO 880,T 88, CAZRI moth-l,etc.

Relatively drought tolerant crop varieties

Source-CAZRI,2000 .Strategy to combat drought and famine in the Indian arid zone

Page 21: Soumya drought and its mitigation

Seed hardening

Seed hardening:

Seed hardening refers to the technique of subjecting seeds to

soaking in water or appropriate chemical solutions and drying

in shade.

It helps the plant to survive during initial moisture stress

conditions.

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Treatments Seed yield

(g plant -1)

100 seed weight

(g)

Harvest index

(%)Seed yield

(q ha -1 )

T1 : Control 9.12 26.64 41.1 19.04

T2 : Water soaking 11.11 28.69 42.0 19.41

T3 : CaC12 (1%) 11.58 29.22 47.1 19.12

T4 : CaC12 (2%) 19.15 30.77 53.1 26.32

T5: KH2PO4 (1%) 13.48 26.66 44.0 22.02

T6:KNO3 (100 ppm) 13.77 30.33 43.6 23.73

T7:KCI (100 ppm) 12.85 24.89 46.2 20.65

T8: Sodium

molybdate (100 ppm)

12.63 24.52 48.6 21.71

T9: Zinc sulphate (100

ppm)

13.2 26.32 48.7 22.34

T10 : Cycocel (1000

ppm)

16.10 27.70 49.2 23.54

T11:Succinic acid (20

ppm)

14.67 27.20 47.5 23.44

T12: Ascorbic acid (20

ppm)

12.96 26.63 46.6 22.45

S E 0.62 0.73 2.05 1.16

CD at (5%) 1.81 2.11 5.95 3.38

Table 2 : Influence of seed hardening chemicals on yield and yield

traits in chickpea.

Dharwad Manjunath (2010)

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Management at sowing

Time of sowing

An increasing in yield has been found by advancing the date of

sowing of kharif and rabi crops.

Advantages

o Better moisture availability

o Good seedling vigour

o Longer growing season

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soil and water conservation method

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Soil and water conservation methods

In-situ moisture conservation practices

Water harvesting structures

Mulching

Anti-transpirants

Adopting modern irrigation techniques

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In-situ moisture conservation practices

Land shaping (if the soil depth permits), contour cultivation, field/contour

bunding, tie ridging , digging of trenches, ridges and furrow system of

sowing, raised on sunken beds are important practices for conserving and

managing rain water for realising higher productivity.

Compartmental bunding

Conservation furrow

Broad bed and furrow

Ridges and furrow

Contour bunding

Graded bunding

Dead furrow

Inter plot rainwater harvesting

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Performance of chickpea varieties as influenced by compartmental bunding at

farmers fields

Bellary Patil et al.,(2015)

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TREATMENTS 30 DAS 60 DAS 90 DAS 120 DAS 150 DAS AT HARVEST

Broad Bed and Furrow

(BBF)

30.67 28.01 30.19 26.72 21.96 13.80

Farmer Practice (Flat

bed-FB)

23.59 24.92 25.44 23.82 19.16 11.94

S.Em+ 0.98 0.07 0.13 0.19 0.09 0.22

CD (P=0.05) 5.94 0.45 0.80 1.13 0.55 1.36

Table 6 : Soil moisture content (%) as influenced in- situ moisture conservation

practices at 45-60 cm soil depth

Alisaheb et al,(2015)

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Water harvesting structures

Water harvesting is the process of collecting rainfall and/or runoff

from a larger catchments area to be used in a smaller target area

(Oweis et. al., 1999). The collected runoff water may be either

directly applied to an adjacent field as supplemental life saving

irrigation of crops during moisture stress condition.

Some of the water harvesting structures are:

• Cisterns/ tankas/ kund• Khadin• Village ponds (Nadis/ tobas)• Series of check dams on natural streams• Percolation tanks

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Cisterns/ tankas/ kundUnderground storage cisterns/ tanka /kund is the most common rainwater harvesting system

in the Indian arid zone.Tanka is constructed by digging a circular hole of 3.00 to 4.25 m

diameters and plastering the base and sides with 6-mm thick lime mortar or 3mm thick

cement.

Khadin:Khadin system of water harvesting and moisture conservation is well suited in deep soil plots

surrounded by some sort of natural catchment zone. Even during severe drought years,

khadins may be used for getting a successful crop on stored soil profile moisture.

Page 32: Soumya drought and its mitigation

Village ponds (Nadis/ tobas):

Nadis /tobas are small to medium sized excavated

or embanked village ponds, for harvesting

precipitation. These ponds can provide water for life

saving irrrigation to crop during drought stress.

Check dams:

In this system the artificial recharge is made to

restrict the surface run off through streams and by

making additional water available for percolation.

Percolation tanks:

Percolation tanks are generally constructed on the

small streams or rivulets with adequate catchment

for impounding surface runoff. These tanks are used

entirely for recharging the aquifer through

percolation

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MULCHING

o Any material used (spread) at surface or vertically in

soil to assist soil and water conservation and soil

productivity is called much. And process of applying

mulches to soil is known as mulching.

o Mulching helps in conserving moisture, lowering soil

temperatures around plant roots, reducing weed

growth, etc thus helps crops during moisture stress

conditions.

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Types of mulches

1.Plastic films:They help in maintaining higher water content in

soil resulted from reduced evaporation, induced

infiltration, reduced transpiration from weeds or

combination of all these factors.

Examples-Polythene, polyvinyl,etc.

2.Crop residues or stubble mulch:

Crop residues and other plant waste products corn,

and sawdust) are widely used as mulch. These

materials are cheep and often readily available. The

permit water to enter in the soil easily, when

maintain at adequate level. These materials result

in increased water content and reduced

evaporation.

Examples- Straw, cloves, leaves,etc.

Page 35: Soumya drought and its mitigation

3.Saw dust mulch:

Mulching with sawdust is a common practice.

Sawdust is acidic, making it a good mulch choice

for acid-loving plants.They have high water

absorption capacity.

4.Soil or Dust mulch:

If the surface of the soil is loosened, it acts as

mulch for reducing evaporation. This loose

surface of soil is called soil mulch or dust mulch.

Inter-culturing creates soil mulch in growing

crops and helps in closing deep cracks in

Vertisols.

5.Vertical mulch:

Vertical mulch is a technique which consists of

digging suitable trenches across the slope and

thus making more surface are a available for

water absorption.

Fig. Vertical mulching

Fig. Saw dust mulching

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EFFECTS OF STRAW MULCH ON MAIZE AND WHEAT

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ANTI-TRANSPIRANTS

Anti-transpirants are the materials or chemicals that applied to

transpiring plant surfaces for reducing water loss from the plant. The

purpose of ATs is to maintain the growth and productivity under

stress conditions and it is never recommended for high productivity /

unit area.

The severity of intermittent drought of 6-10 days during critical

stages of the crop can reasonably be avoided by the use of

antitranspirants and thus crops can be save

Mainly four types of anti-transpirants:

1. Stomatal closing type

2. Film forming type

3. Reflectance type

4. Growth retardant

Page 38: Soumya drought and its mitigation

Stomatal closing type:

Most of the transpiration occur through the stomata on the leaf surface. They induce

stomatal closing or decrease size and number of stomata which subsequently reduce the

photosynthesis.

Examples:

• Phenyl Mercuric Acetate (PMA)

• Atrazine

Film forming type:

Plastic and waxy material which form a thin colourless film over the leaf surface and result

in a physical barrier. These glossy films then reduce water loss on plants while at the same

time allow them to breathe normally.

Examples:

• Hexadecanol (Higher alcohols)

• Cetyl alcohol

• Methanol

• Paclobutrazol

• Brassinolide

• Resorcinol

Page 39: Soumya drought and its mitigation

Reflecting type:

They are white materials which form a coating on the leaves and increase the leaf

reflectance (albedo). By reflecting the radiation, vapour pressure gradient and thus reduce

transpiration.

Examples:

• Kaoline(5%)

• China Clay

• Calcium bicarbonate

• Lime water

Growth retardant:

These chemicals reduce shoot growth and increase root growth and thus enable the plants

to resist drought. They may also induce stomatal closure.

Examples:

• cycocel

Page 40: Soumya drought and its mitigation

Modern irrigation techniques

Sprinkler and drip irrigation methods are most suitable moisture stress

conditions. These methods help in water conservation. The conveyance losses

of water are practically negligible, and risk of soil erosion is low as the

application rate is low.

Sprinkler system is most suitable for narrow-spacing crops grown on undulating

light textured soils. The drip irrigation system is not affected by high wind velocity

as it applies water directly in the root zone. This method of irrigation is more

suitable for wider spacing crops and orchards. As the irrigation is given directly

near the root zone in drip system and whole soil surface is not wetted. wasteful

loss of water is minimized.

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Contingency crop planning Late onset of monsoon : Transplanting

Alternate crops/varieties

Dry spells during crop periods : Ratooning and thinning

Mulching

Spraying of urea(2%)

Weed control

Water harvesting and life saving irrigation

Early withdrawal of monsoon : Harvesting at physiological maturity

Short duration varieties

Strategies adopted for mitigating dry spells during crop periods

can be done

S.R Reddy, Principles of Agronomy

Page 42: Soumya drought and its mitigation

SOME OTHER LONG TERM

STRATEGIES TO MITIGATE

DROUGHT

Page 43: Soumya drought and its mitigation

Long-range forecast :

It is in purview of IMD and accurate oceanographic pre-monsoon

conditions.Besides, date of onset and withdrawal of monsoon, accurate

forecast about amount and distribution of rainfall in ensuing kharif

season would be of great value for planners as well as farmers to

develop contingent plans, rather a all season weather coat, for

drought.as well as floods.

IRS P-4 satellite with Oceansat OCM, MSMR sensor may prove of

great value in studying ocean situation. Great emphasis is to be laid in

future on long-range forecasts to combat drought.

These forecasts are given for the benefit of farmers for planning their

agricultural operations and crop selection and for planners for advance

planning in case of an anticipated flood or drought

Source- CAZRI,2000. Strategy to combat drought and famine

Page 44: Soumya drought and its mitigation

ALTERNATE LAND USE SYSTEM

Practicing alternate land use such as agro-forestry, agro-

horticulture and silvi-pasture would provide long-term

drought proofing in the Indian arid zone.

Page 45: Soumya drought and its mitigation

• Crop improvement for drought tolerance or escape, seed priming,

early sowing, soil conservation practices including tillage which

conserve moisture, in-situ moisture conservation practices and

water harvesting and use of antitranspirants and reflectants are

some of the mitigation strategies

• Breeding for drought resistance crop varieties i.e development of

transgenic plants for drought tolerance

• Adoption of long term strategies like integration of small

reservoirs with major reservoirs, integrated basin planning, etc.

• Long range rainfall forecast can prove as a warning tool for

drought mitigation

Conclusion

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