This document discusses various types of environmental stresses that can affect plant growth including drought, high or low temperatures, excessive soil salinity, and inadequate minerals in the soil. It describes different mechanisms by which plants can adapt to or tolerate drought conditions, such as escaping drought by having a short lifecycle, avoiding stress through stomatal regulation and increased photosynthetic efficiency, and tolerating stress through enhanced water conservation and storage abilities. The document focuses on defining and classifying different types of drought, as well as adaptation strategies employed by crops to survive in drought environments.

1. ABHILASH
2016A55D
Ph.D. Student
Dept. of Agricultural
Meteorology
ASSIGNMENT
Dr. A. K. Dhaka (Prof.)
Dept. of Agronomy
CCS Haryana Agricultural
University, Hisar

2. Stress
 Stress External conditions that adversely affect growth, development, or productivity
 Stresses trigger a wide range of plant responses:
•altered gene expression
•cellular metabolism
•changes in growth rates and crop yields
 These environmental factors affecting plant growth & yield are related to climate, soil &
the plant itself.
 To produce a good yield, it is important that all the environmental factors should be at
optimum levels.
 The factors are of two types:
 Abiotic : Environment, soil & nutrients.
 Biotic: Weeds,insect pests & diseases.
Biotic and abiotic stresses can reduce average plant productivity by 65% to 87%,
depending on the crop

3. Environmental conditions that can cause stress
• WATER-LOGGING
• DROUGHT
• HIGH OR LOW TEMPERATURES
• EXCESSIVE SOIL SALINITY
• INADEQUATE MINERAL IN THE SOIL
• TOO MUCH OR TOO LITTLE LIGHT
• PHYTOTOXIC COMPOUNDS LIKE OZONE

4. Factors that determine plant stress responses
RESISTANCE OR SENSITIVITY OF PLANTS TO STRESS DEPENDS ON:
•THE SPECIES
•THE GENOTYPE
•DEVELOPMENT AGE

5. Moisture
Water is essential for growth and development of plants
from germination to maturity.
Water present in large vacuoles and cells provide
turgidity to tissues.
It is essential for many of the physiological processes
related to
Photosynthesis
Growth of cells, tissues, and organs
Which ultimately forms growth and yield of most of
the crop plants.

6. Moisture Stress
Water is paramount factor in determining distribution of plant species
on earth’s surface.
Where water is present in abundant amount & evenly distributed, plant
growth is lush.
As the precipitation becomes less abundant & less frequent, forests
changes into grasslands first & finally changed into deserts.
Drought, being the most important environmental stress, severely
impairs plant growth and development, limits plant production and the
performance of crop plants, more than any other environmental factor
(Shao et al., 2009).
Parameters to measure water stress:
Leaf water potential (By Quarrie & Jones,1979)
Leaf conductance/leaf permeability to water loss(Jones,1977)
Osmotic adjustments (Morgan,1977)
Plant water status (Turner,1986)

7. • Plant growth and development
• Seed germination and seedling establishment
• Root-shoot ratio
• Photosynthesis
• Carbohydrate and protein metabolism
• Growth regulators
• Reproductive development of plants
• Pathogen and insect-attack
Effects of Water deficit Stress

8. Plant response to water stress:
Water is very essential for plant growth;
PLANT METABOLISM
PHYSIOLOGY
MORPHOLOGY.
The morphological, physiological & biochemical responses to plants to water deficits
generally vary with the severity as well as the duration of the stress.
The critical growth stage of specific crops more sensitive to water stress.
Grain crops are very sensitive to water stress in the 2 weeks immediately preceding
anthesis.(Fageria,1980).
Drought during pod filling in cowpea & at silking stage in maize is very sensitive to
drought (Turk et al.,1980 & Grant,1989).

9. DROUGHT
No universal definition
FAO (1983) defines drought hazard as “the percentage of years
when crop fails from the lack of moisture.”
WMO (1986) “drought means a sustained, extended deficiency in
precipitation”
IMD (1967) “Drought is the consequence of a natural reduction in
the amount of precipitation over an extended period of time, usually
a season or more in length, often associated with other climatic
factors (viz. high temperatures, high winds and low relative
humidity) that can aggravate the severity of the drought event.”
IPCC AR5 (2014) defines drought hazard as “a period of
abnormally dry weather long enough to cause a serious hydrological
imbalance”.

10. Importance of Monitoring and Forecasting of Agricultural Drought
The frequency of drought in India is increasing.
1950-1990 – 10 drought years
since 2000 – 6 drought years (2002, 2004, 2009, 2014 ,2015 and 2016)
68 % of the net sown area in India is prone to drought.
Monitoring and forecasting are part of preparedness that helps in reducing the
impact of drought by following practices:
Selection of crop management practices
Contingency planning
Policy formulation
Crop/ Livestock insurance
Watershed management
Agro-advisories
Monitoring helps in providing relief measures to severely affected areas.

11. Source: National Drought Mitigation Center, University of Nebraska – Lincoln,
Natural Climatic Variability
Precipitation deficiency High temperature, high
winds, low R.H., greater
sunshine, less cloud cover
Soil water deficiency
Plant water stress,
reduced biomass and yield
Reduced stream flow,
inflow to reservoirs, lakes
and ponds
HydrologicalAgriculturalMeteorological
DroughtDroughtDrought
Socio-economic impact
Time(duration)

12. Classes of droughts
National Commission on Agriculture (NCA, 1976) recognized drought as
given below:
1. Meteorological drought: defined as a situation where there is 20%
decrease in the average rainfall for a said period in a region
(IMD, GOI).
2. Hydrological Drought: occurs when there is prolonged
meteorological drought resulting into marked depletion of
surface water and consequent drying of water reservoirs like,
lakes, rivers, ponds, streams, etc.
3. Agricultural Drought: occurs when soil moisture and rainfall are
inadequate during the growing season to support a healthy
growing crop. When it occurs at any critical stage of crop growth,
it is most critical.

13.  Adaptation is defined as the activities by individuals,
groups and governments that aim “to reduce the
vulnerability of human or natural systems from the
impacts of climate change and climate-related risks,
by maintaining or increasing adaptive capacity and
systems resilience.
Adaptive capacity: ability of a system to adjust to
climate change (climate variability and extremes) to
moderate potential damages, to take advantage of
opportunities, or to cope with the consequences.
Vulnerability : degree to which a system or society is
susceptible to, and unable to cope with adverse effects of
climate change, including climate variability and
extremes.
Resilience: ability to absorb disturbances, to be
changed and then to re-organize and still have the same
identity (retain the same basic structure and ways of
functioning).
Adaptation of crops to drought environment

14. Adaptation is heritable modification in structure or function
that increase the probability of an organism surviving and
reproducing in a particular environment.
Adaptation of an organism to an environment depends on
possession of an optimum combination of characters that
minimize the deleterious effects and maximize the
advantageous effects.
For ex., plants growing in dry habitat accumulated various
modifications of characters with adaptive values, such as,
thick cuticle, extensive root system, low osmotic potential,
tolerance of dehydration etc.
Adaptation of crops to drought environment

16. Adaptation of crops to drought environment
Crops survive and grow under moisture stress conditions mainly by
two ways:
(A) Escaping drought:-Evading the periods of drought is the simplest
means of adaptation of plants to dry conditions. Many desert plants have
an extremely short life period (5 to 6 weeks) which is confined to the
rainy season/period, called ephemerals e.g., cowpea, green gram, black
gram. Certain varieties of pearl millet mature within 60 days after
sowing.
(B) Drought resistance:- Plants can adopt to drought either by avoiding
stress or by tolerating stress due to different mechanisms.

17. Avoiding stress
It is the ability to maintain a favorable water balance & turgidly
even when exposed to drought condition, thereby avoiding stress &
its consequences.
It can be achieved either by
(a) conserving water by restricting transpiration before or as soon as
stress is experienced
(b) (b) accelerating water uptake sufficiently so as to replenish the
lost water.

18. Mechanism to conserve water
(i) Stomatal mechanism:- Drought resistance varieties open their stomata more
rapidly in the early morning when moisture stress is at minimum & photosynthesis
can proceed with the least loss of water.
(ii) Increased photosynthetic efficiency:- In C4 plants, the carboxylating enzymes
namely phosphoenolpyruvic acid carboxylase has very high affinity for CO2 &
high potential activity. Therefore for the same amount of Stomatal opening, C4
plants have higher photosynthetic rate than C3 plants. In addition , C4 plants can
translocate photosynthates more rapidly. The C4 plants are sorghum, maize,
pearlmillet, sugarcane etc. the plants with CAM type of photosynthesis are
pineapple & agave.
(iii) Lipid deposits on leaves:- Some plants like soybean, sorghum, etc., reduce water
loss by depositing lipids on plant surfaces under moisture stress.
(iv) Leaf surface:- Leaves with thick cuticle, waxy surface & spines are common and
effective.

19. Mechanism to conserve water
(v). Reduction in leaf area:- In grasses, the leaves roll or curl due to moisture stress &
thus reduce the area exposed to solar radiation resulting in low transpiration.
Leguminous plants show parahelionastic movement i.e., the leaves are oriented
parallel to sun rays thus avoiding the load of solar radiation. The leaflets are
horizontal to the sun rays during morning & evening. However, when the solar
radiation is high, the leaves fold & reduce transpiration. Moisture stressed
groundnut plants reduce radiation load during midday by about 60 to 70% due to
folding of leaves. Senescence or dropping of leaves is another mechanism for
reducing leaf area but premature senescence of leaves causes reduction in yield.
(vi) Effect of awns:- Awned varieties give more yield under drought condition
compared to awnless varieties. Awns contribute about 12% of photosynthates to
grain.
(vii) Water storage in plants:- Water storage may confer an adaptive mechanism in
pineapple in dry condition because its transpiration rate is very low compared to
most of the crop plants.

20. Mechanism to improve water uptake
Drought avoidance is promoted by well developed deep root system with high
efficiency to extract water from deeper layers of soil.
This mechanism is desirable only if there is sufficient soil moisture in deeper layers for
extraction.
Water uptake can be improved by several mechanisms:
(i) Efficient root system:- It is an important morphological adaptation that helps in
drought resistance without losing productivity. Genetic variability in root length is
observed in soybean, wheat & tomato.
(ii) Root-shoot ratio:- If the roots are more compared to transpiring shoots, water
balance can be maintained.
(iii) Increase in liquid phase conductance :- Lowering of resistance to water can be
achieved by increasing either diameter of xylem vessels or their number.

21. Drought tolerance
Drought tolerance can be defined as tolerance of the plants to a level of
stress at which 50% of the cells die. Drought tolerance is either by
mitigating stress or by showing high degree of tolerance.
(I) Mitigating stress:- By resisting dehydration & maintenance of higher
osmotic pressure by accumulating higher amounts of solutes. The leaves
with thick cuticle resist cell collapse.
(ii) High degree of tolerance:- Death of cells occur either due to
reduction in photosynthesis or protein synthesis. The plants capable of
keeping the stomata partially open can photosynthesize & survive. Young
leaves are more resistant to drought than older leaves due to higher
protein content. In many species of perennial plants, the above ground
parts die-off during drought & underground parts such as rhizomes,
bulbs, tubers etc., remain alive but dormant.

22. Drought evaluation
Identifying drought resistant plants with desirable attributes requires the knowledge of
developmental, morphological, anatomical and physiological attributes that contribute
to crop adaptation in arid & semi-arid environments.
(a) Developmental mechanism:- In crop plants, greatest advances in breeding for
water limited environments have been achieved by shortening life cycle. Small amount
of indeterminacy, branching & tillering is essential for flexibility for varying ecological
conditions.
(b) Anatomical adaptation:- Reduction of resistance to water flow can be achieved by
increasing either the diameter of the xylem vessels or their number.
(c ) Remobilization of reserves:- There are two sources of assimilate supply for grain
development of cereals & legumes i.e.from photosynthesis before anthesis & after
anthesis. Under normal conditions, contribution of pre-anthesis assimilates to grain is
less than 20% in the most plants except in rice where it ranges from 20 to 40 %. But
under moisture stress condition, it may be upto 50 to 75%. Limited success in
identifying wheat or barley lines which transfer more pre-anthesis assimilates to the
grain under stress than under non-stress conditions.

23. Drought evaluation
(d) Morphological adaptations:-
(1) Change in leaf angle e.g., most of the legumes & sunflower show this foliar movement.
(2) Reduced size of shoots.
(3) Increase in size of root system.
(4) Thicker cuticle & cell walls, with more lipids on the transpiring surfaces.
(5) Better developed palisade mesophyll.
(6) Weaker development of sponge mesophyll.
(7) Smaller intercellular spaces.
(8) Smaller xylem cells, but greater proportion of heavily lignified tissues.
(9) Smaller cells in the leaves, which in turn results in:
(i) Smaller blades or blade segments.
(ii) Stomata smaller & closer together.
(iii) Smaller vein-lets.
(iv) More hairs per unit area.

24. Drought evaluation
(e) Physiological adaptations:-
(1) More rapid rate of photosynthesis per unit area.
(2) More rapid rate of transpiration per unit area, although net transpiration per plant
may be reduced.
(3) Lower starch to sugar ratio.
(4) Higher osmotic pressure.
(5) Lower protoplasmic viscosity.
(6) Increased protoplasmic permeability.
(7) Greater resistant to wilting.
(8) Earlier flowering & fruiting.
(9) Increasing the percentage of bound water per unit dry weight of tissue.

25. Flooding Stress
Also known as O2 deficiency, water logging & anaerobiosis.
All involve a depletion in O2 & build up of CO2, ethylene & other potentially
toxic gases.
Once soil becomes waterlogged, airspace is displaced with water.
Oxygen replenishment in the soil is very inefficient because of the slow
diffusion of atmospheric O2 into waterlogged soil.
Ethylene concentration also increases in waterlogged plants. It also reduces the
soil redox potential, changes soil pH & increase the concentration of toxic ions,
metals,fatty acids, phenolic compounds & ethylene found in the soil.

26. Flooding Stress
Physiological & biochemical responses of plants to water logging:
The physiological & biochemical effects of water logging include change in
respiratory metabolism, root permeability,water & mineral uptake,N2 fixation &
endogenous hormones. In tomato & sunflower, epinasty (downward growth of
petioles)takes place due to water logging.
• Various terms such as anoxia, anaerobiosis, waterlogging and flooding have been
used in the literature for excess water in the soil.
• All these terms involve a depletion of oxygen and accumulation of carbon dioxide,
ethylene and other potentially toxic gases which exert adverse effect on plant
growth and development.
• FAO/UNESCO (1973) defined waterlogged areas as those where soils are
temporarily saturated or where the groundwater table is too shallow such that
capillary rise of water encroaches upon the crop root zone and may even reach the
soil surface.

27. CAUSES OF WATERLOGGING
Poor natural drainage as a consequence of unfavourable topography or
unfavourable sub-soil geology like existence of hardpan at shallow depths.
Heavy storm rainfall coupled with poor natural drainage.
Spilling of rivers resulting in submergence of agricultural lands.
Heavy losses of water due to seepage from canals, distributaries and
watercourses.
Poor on-farm water management resulting in poor application efficiencies.
Development activities such as construction of roads, bridges, railway lines and
buildings resulting in choking of natural drainage.
Poor maintenance of existing drainage system and outlets.
Deforestation and poor upkeep of watersheds.

28. IRRIGATION INDUCED WATERLOGGING
The water logging in irrigation commands could appear in the following forms:
Surface ponding of water: Due to water stagnation on the land surface as a result of inadequate surface drainage.
Rise in water table: Due to ground water levels rising and remaining in the root zone to adversely affect the crops.
 The problem of rising water table is more serious in arid and semi arid areas of our country.
 Water table has been rising at 0.6m per year in command areas of Western Yamuna Canal.
 Even in the driest part of the country as in Rajasthan, a steep rise in water table has been reported varying from
0.6m per annum in Ganga canal areas to 1.0m per annum in Indira Canal areas.
 These reports confirm the fact that once canal irrigation is introduced the water table rise is inevitable.
 Since the inception of canal irrigation, the annual rise in water table in sizable canal command areas of Central
and Western districts of Haryana viz, Sirsa, Hisar, Bhiwani, Rohtak and Jind has been at the rate of 15 to 90cm.
 By 1997, nearly 16% area of the state had come in the danger zone with water table within 2.5m and in the
vicinity of canals it has come very close to the surface.
 At CCS HAU farm, where water table was more than 15m deep in 1967 at the time of introduction of irrigation
under Bhakra Canal system has now come very close to the ground surface at a depth of less than 2m.

29. EFFECTS OF WATERLOGGING ON SOIL PROPERTIES
(a) Effect on physical properties:
 Lack of aeration in crop root zone
 Difficulty in soil workability
 Deterioration of soil structure
 Leaching of nutrients like nitrogen
(b) Effect on biological properties:
 Reduction in microbial activities
 Decrease in population of aerobes in favour of anaerobes resulting in root
rot in many crops

30. EFFECTS OF WATERLOGGING ON SOIL PROPERTIES
(c) Effect on chemical properties:
 Depletion of molecular oxygen
 Decrease in redox potential of soil
 Increase in pH of acid soils and decrease in pH of calcarious and sodic soils
 Increase in specific conductance
 Reduction of Fe3+ to Fe+2 and Mn4+ to Mn2+
 Reduction of NO-
3 and NO-
2 to N2 and N2O, i.e. denitrification
 Reduction of SO4 to S2-
 Increase in supply and availability of N
 Increase in availability of P, Si and Mo
 Decrease in concentrations of water soluble Zn and Cu
 Generation of CO2, CH4, and toxic reduction products such as organic acids
and H2S

31. RESPONSE OF PLANTS TO WATERLOGGING
 One of the most rapid, visible responses of plants, such as
tomato and sunflower to waterlogging is the downward growth
of the petioles known as epinasty.
 This epinastic movement of the leaves is caused by more rapid
expansion of the cells on upper side of the petiole than of those
on the lower side.
 Epinasty is not associated with wilting or low leaf water
potential, since it is a growth process that requires turgor for
leaf expansion.
 It is reported that this type of behaviour of plants is related to
ethylene production in water logged soils.

32. ALLEVIATING EFFECTS OF WATERLOGGING
1. Adequate Drainage: Adequate drainage system removes excess water from crop root zone and
provides favourable conditions for crop growth. Various benefits of drainage are given below:
 Improves aeration of water logged soils
 Improves soil structure and infiltration capacity and maintain the desirable temperatures.
 Provides optimum conditions for tillage over a long range of time.
 Promotes increased leaching of salts and prevents their accumulation in the plough layer of
the soil
2. Selecting Appropriate crop:
 Rice and finger millet may be preferred for water logged soils during kharif season.
 Wheat may be preferred to other winter crops during kharif season.
3. Seed Rate: In saline water logged areas, about 25% higher seed rate should be used to
compensate the reduction in yield due to poor germination and poor tillering.
4. Planting Techniques: Planting should be done on mounds or ridges or raised beds so that the crop
escapes complete submergence.
5. Fertilizer Management: Use nearly 25% higher dose of N than the normal recommended dose to
compensate leaching and denitrification loses.

33. Adaptation of Plants in Water logged areas
1) Low osmotic pressure of cells saves from absorption of unwanted water.
2) Mucilage on the surface of aquatic plants protects from bacteria and fungus.
3) Absence of cuticle and waxes on body of plants.
4) Aerenchyma presence which provides Buoyancy to the plant and store the O2 produced in
Photosynthesis & Chlorenchyma tissues are well developed.
5) Chloroplasts on epidermis for better photosynthesis.
6) Mechanical tissues like Sclerenchyma are either absent or less developed which make plants
soft.
8) Conducting tissues like Xylem and Phloem are poorly developed.
9) Root system of hydrophytes are either absent or reduced. At the place of root tips, root pockets
are present which are filled by air.
10) The leaves are Astomatic in suspended and submerged plants as whole plant body exchanges
gases. The floating plants have Epistomatic nature leaves ,it means stomatas are present on
upper surface of leaves only.
11) Most of the hydrophytes are vegetatively reproduced.

34. Temperature stress:
Temperature controls
RATE OF PHOTOSYNTHESIS
RESPIRATION
INFLUENCES FLOWERING
PHOTOSYNTHATE DISTRIBUTION
MATURITY.
Different crops & even varieties of the same crop species, require
specific temperature ranges for the best performance.
Two types of stresses:
HYPERTHERMIA/HIGH TEMPERATURE INJURY
HYPOTHERMIA/FREEZING INJURY

35. HYPERTHERMIA/HIGH TEMPERATURE INJURY
Due to high temperature many cytological changes occur like
COAGULATION OF THE PROTOPLASM
CYTOLYSIS
NUCLEAR CHANGES
ALTERED MITOSIS
INHIBITION OF PROTOPLASMIC STEAMING
INCREASED PROTOPLASMIC VISCOSITY
LOSS OF MEMBRANE SEMIPERMEABILITY.
Due to high temperature many biochemical changes occur like
•REDUCTION IN PROTEIN CONTENT
•CHLOROPHYLL CONTENT
•NUCLEIC ACID CONTENT
Management: By manipulating date of sowing, application of light and frequent irrigation.

36. Results show that maize yields are expected to be negatively affected by climate change, while
the impacts on wheat and soybean are generally positive, unless CO2 fertilisation effects have
been overestimated. (Deryng et al, 2014)

37. HYPOTHERMIA/FREEZING INJURY
Super cooling of the cell & its external solution often precedes freezing.
Dehydration from the extracellular freezing eventually causes severe
contraction of the cell & sometimes collapse of the protoplast. The injuries
induced by the dehydration include decreased cell volume below some
critical level, decreased separation of functional macromolecules, increased
intercellular & extracellular solute concentration, solute
precipitation,adverse ph changes & gas exchange interference from ice
itself.
Plant response to temperature:
Temperature influences:
1. Seed germination & emergence
2. Root growth
3. Water & nutrient absorption
4. Growth & yield
Management: Apply light irrigation in the evening, making smoke during night hours,
cover plants with shade of straw leaving space on south side for sun light during day
time.

38. Response of temperature in growth:
1. Root temperature affected root extension, means radius,root
surface area, numbers & length of root hairs of Barley & oil seed
rape.
2. Root length of Barley increased with temperature in range of 3-
250C, by a factor of 27 after 20 days.
3. Temperature influences portioning of growth between shoot &
root.

39. Response of temperature in yield
1. An increase in seed growth rate of Soyabean from 6.1-6.9
mg/seed/day as temperature increased from 18/13 to 27/220 C but
no further change as temperature increased to 33/280 C (Egli &
Wardlaw,1980)
2. Kernel growth duration of wheat from approximately 60 days at
temperature 15/100 C to approximately 25 days at 30/250C
(Sofield et al.,1977).
3. Sorghum’s kernel growth duration decreased from
approximately 45 days at 21/160 C to 15 days at 36/310C
(Chaudhary & Wardlaw,1978).

40. Solar radiation stress
•Solar radiation controls metamorphosis & production in crop plants.
•It affects the type of growth,synthesis of food materials,differentiation
of tissues & organs & maturity of various crops.
•Photosynthesis can not take place without light.
•Carbohydrate accumulation is associated with high radiation intensity.
Radiation & growth phase:
•The critical periods in relation to solar radiation are the reproductive &
ripening growth stages.
•High irradiance at any stage after panicle initiation was associated with
higher yields in both older & modern varieties of rice.

41. Salinity stress
Salinity is the presence of an excessive concentration of soluble salts
that suppresses plant growth.
Salinity occurs normally in arid & semiarid regions where rainfall is
insufficient to leach salts from the root zone.
Plant response to salinity:
1. Affected plants are stunted & have smaller dark green leaves.
2. Many physiological & biochemical effects of salinity are turgor reduction,
inhibition of membrane function or enzyme activity, inhibition of photosynthesis,
induction of ion deficiency from inadequate transport & increased use of metabolic
energy for processes involved in maintenance of tolerance.
3. Uptake & utilization of mineral nutrients by plants are adversely affected under
high salt concentration.
4. Reduction in root permeability & the consequent decrease in water & nutrient
uptake.
5. N2 fixation is reduced due to limited nodule formation by reducing population of
Rhizobium.

42. Soil Type ECe (dS/m) ESP (%) pH
Saline >4 <15 <8.5
Saline-
sodic
>4 >15 < 8.5
Sodic <4 >15 >8.5
Characteristics of salt affected soils

43. Soil erosion stress
Water & soil erosion has long been associated with agriculture
throughout the world.
When land is cleared of natural vegetations, the natural protection of soil
is lost & soil erosion takes place at great speeds.
The principle causes of erosion are deforestation, overgrazing of pasture
lands & poor use of shifting cultivation practices.
Effect on yield:
Soil erosion removes essential plant nutrients that are mostly
concentrated on topsoil layers.
Erosion reduces soil water holding capacity, decrease organic matter
content & consequently decreases crop yield.
Soil erosion also causes a change in soil profile & reduces the yield.

44. • Mulch farming
• Planting the cover crops
• No tillage (Zero tillage) farming
• Appropriate crop rotation
• Contour farming
• Construction of terraces and diversions bases
in sloppy lands.
• Keeping the land under pastures
Control measures to reduce soil erosion

45. Maintenance of soil cover is the key to controlling erosion in agricultural lands.
It prevents erosion by maintaining the soil in a condition that absorbs rainfall.
Any runoff that does result will be impeded by the cover and is less likely to
concentrate into an erosive force.
Erosion risk is significantly reduced when there is more than 30% soil cover.
Total cover is achievable for many grazing and cropping systems.

46. SYMBOL OF TRUST