Deshraj Singh Suman

Introduction
Agriculture and Environment
 Food production in India has increased from 69 million tonnes in 1965 to 264.4 million
tonnes in 2013 – 14, cereals productivity has increased from almost 10 to 30 q ha-1.
 If the yield improvement would not have taken place, we would at present have required
another 70 million hectares land to produce the food grains to meet our requirements. Since
land is finite, this additional land would have come from deforestation.
The most imminent of the environmental changes of the earth is the increase in the
atmospheric temperature due to increased levels of CO2 and other GHGs.
The quantity of rainfall and its occurrence has also become more uncertain. In certain
places, climatic extremes such as drought, floods, rainfall distributions and snowmelt have
increased.
The sea level has risen by 10 – 20 cm depending upon the region. Similarly, snow cover is
also believed to be gradually decreasing.
The global mean annual temperature at the end of the 20th century was almost 0.5 to 0.7° C
above that recorded at the end of the 19th century. It is projected that the average temperature
of the air would rise by 1.9 to 4.6° C over the next 100 years.
Natural calamities viz. more floods, frequent droughts and forest fires, decrease in
agricultural and aquacultural productivity, displacement of coastal dwellers by sea level rise
and intense tropical cyclones, and the degradation of mangroves are projected to be some of
the likely consequences of such environmental changes in Asia. 3

Before Green Revolution
Agriculture and Environment4
Starvation

Father of the Global Green Revolution
Nobel laureate Dr. Norman Ernst Borlaug

Father of Green Revolution in India
Dr. M. S. Swaminathan

1. High yielding varieties
2. Irrigation facilities 3. Chemical use
Major reasons of green revolution

To identify existing and emerging constraints limiting productivity
and opportunity for sustainable increase in the future, It is important to
understand agriculture-environment interactions in totality. This would
include identification of the key environmental problems from an agricultural
perspective, impact of these on agriculture, impact agricultural activities on
the environment, and restoration of environment by agriculture.
The objectives of the seminar are to discuss:
1. The current environment issues and their impact on Indian
agriculture.
2. Tools and indices for environmental impact assessment.
3. Approaches for environmental restoration. And
4. Initiatives and legislations for combating environmental change.
Cont...

Environmental issues and their impact on agriculture
The major environmental issues that Indian
agriculture is currently confronting stem from
global climate change because of emission of
GHGs, water, soil, air pollution emanating from
industry, transport, fertilizer application and
persistent organic pollutants: and loss of
biodiversity.
1. Global climate change
2. Emission of green house gases (GHGs)
3. Water pollution
4. Soil pollution
5. Air pollution
6. Loss of biodiversity Agriculture and Environment9

Global climate change
Over the past decades, the gaseous composition of the
atmosphere has undergone a significant change mainly through
1. increased industrial emissions,
2. fossil fuel combustion,
3. widespread and deforestation and
4. burning of biomass, as well as
5. changes in land use and land management practices.
These anthropogenic activities has resulted in an
increased emission of naturally occurring radioactive gases, e.g.
carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O),
popularly known as the ‘green house gases’. These GHGs trap
outgoing infrared radiations from the earth’s surface and thus
raise temperature.
10

Cont...
Parameters CO2 CH4 N2O
Chlorofluoro-
carbons
Avg. conc. 100 years ago
(ppbV)
2,90,000 900 270 0
Current conc. (ppbV) 3,80,000 1,774 319 3 - 5
Projected conc. in the year
2030 (ppbV)
4,00,000-
5,00,000
2,800 –
3,000
400 – 500 3 – 6
Atmospheric life time (years) 5 – 200 9 – 15 114 75
Global warming potential
(100 years relative to CO2)
1 25 298 4,750-10,900
Table : Abundance and lifetime of GHGs in the atmosphere
11

Agriculture and EnvironmentEmission of green house gases (GHGs)
13

Contribution of major sectors to emission of GHGs in India
14
Energy
61%
Waste
2%
Industrial
process
8%
Agriculture
28%
Land use
change
1%

Emission of green house gases (GHGs)
Carbon dioxide (CO2)
Sources:
1. Decay of organic matter
2. Forest fires
3. Volcanoes
4. Burning of fossil fuels
5. Deforestation & land-use change
6. Plant, oceans and atmospheric reactions
18

Methane (CH4)
Methane is about 25 times more effective than
CO2 as a heat trapping gas.
Sources:
1. Wetlands (Mars)
2. Organic decay
3. Termites
4. Natural gas & Oil extraction
5. Biomass burning
6. Rice cultivation
7. Cattle
8. Soil
19

Methane (CH4)
Primary source of methane from
agriculture include
1.Animal digestive process
2.Rice cultivation
3.Manure storage & handling
20
Cont...

Methane (CH4)
Methane is formed in soil through metabolic activities
of a small but highly specific bacterial group
called methanogens.
Their activity increases in submerged, anaerobic
conditions developed in wetland rice fields, which
limit the transport of oxygen into the soil, and
the microbial activities render water saturated
soil practically devoid of oxygen. The upland,
aerobic soil does not produce methane. Water
management, therefore plays a major role in
methane emission.
21

Nitrous oxide (N2O)
As a GHG, nitrous oxide is 298 times effective
than CO2.
Sources:
1. Forests
2. Grasslands
3. Oceans
4. Soils
5. Nitrogenous fertilizers
6. Burning of biomass
7. Fossil fuels
While it is removed by oxidation in the atmosphere.
22

Nitrous oxide (N2O)
Soil contributes about 65 % of total N2O
emission.
Primary source of Nitrous oxide (N2O)
from agriculture include:
1. Soil cultivation
2. Fertilizer & manure application
3. Burning organic material & Fossil fuels
4. Nitrification
5. Denitrifiction
From an agriculture perspective, Nitrous oxide
(N2O) emission from soil represents a loss soil
nitrogen, reducing the nitrogen use efficiency (NUE).
23

Crop residues
1%
Enteric
fermentation
59%Emission from
soils
12%
Manure
management
5%
Rice cultivation
23%
Relative contribution of sub-sectors of
agriculture to emission in India
24

Water pollution
About 3 million ha land in the country is covered under water reservoirs.
In some parts of country, freshwater resources are getting polluted due
to discharge in them of effluents from industry and urban sewage
as well as leaching and runoff of chemicals used in agriculture. Such
polluted water when used for irrigation can be harmful to crops.
Sources:
Point source : Organics or metal entering surface water discharge from
municipalities or industrial complexes
Non point source : Diffuse sources as a result of urban, industrial area
or rural run off, e.g. sediments and pesticides or nitrates, due to
surface run off from agricultural farms.
Increasing application of fertilizers and pesticides in
agriculture can often result in their leaching or run off
to water bodies. This is largely in areas where fertilizer
application is high, irrigations are frequent, soil texture
is sandy and water table is shallow.
25

Table : Quality parameters of freshwater for different uses. @ CPCB
26
Use Drinking water
without
conventional
treatment
Outdoor
bathing
Drinking
water with
conventional
treatment
Propagation of
wild life,
fisheries
Irrigation,
industrial cooling,
controlled waste
disposal
Class A B C D E
Parameters Values
Total coliform organisms per 100 ml <50 <500 <5000
pH 6.5 – 8.5 6.5 – 8.5 6 – 9 6.5 – 8.5 6.5 – 8.5
EC <2.25
SAR <26
Dissolved oxygen (mg lit-1) >6 >5 >4 >4
BOD (mg lit-1) <2 <3 <3
Total dissolved solids (mg lit-1) <500 <2100
Free ammonia as (N) (mg lit-1) 1.2
Chlorides (Cl) (mg lit-1) <250 <600
Boron (B) (mg lit-1) 2
Colour (Hazen unit) <10
Sulphates (SO4) (mg lit-1) 400 1000
Nitrate (NO3) (mg lit-1) 45 20
Arsenic (As) (mg lit-1) 0.05
Iron (Fe) (mg lit-1) 0.3
Fluorides (F) (mg lit-1) 1.5
Lead (Pb) (mg lit-1) 0.1
Copper (Cu) (mg lit-1) 1.5
Zinc (Zn) (mg lit-1) 15

Table. Permissible limits for industrial effluent discharge on land for
irrigation.
Sr.
No.
Parameters Permissible limits
1. pH 5.5 – 9.0
2. Biological Oxygen Demand (BOD) for 5 days at 20º C 100
3. Suspended solids (mg litre-1) 200
4. Total dissolved inorganic solids (mg litre-1) 2100
5. Oil and grease (mg litre-1) 10
6. Cyanides (mg litre-1) 0.2
7. Arsenic (mg litre-1) 0.2
8. Chlorides (mg litre-1) 600
9. Boron (mg litre-1) 2
10. Sulphate (mg litre-1) 1000
11. Sodium (%) 60
12. Alpha emitters (milli curie ml-1) 10 – 8
13. Beta emitters (Curie ml-1) 10 – 7

Water pollution Agriculture and Environment
28

Effect on water
 Water become unfit for
drinking.
 The runoff of
agrochemicals into
streams, lakes, and other
surface waters can
increase the growth of
algae.
 Eutrophication- Change in
quality and composition
of aquatic ecosystems by
accumulation of
excessive chemicals in
water bodies.

 Polluted water
leading to the
death of fish and
other aquatic
animals.
 Excessive use of
agrochemicals has
led to the
contamination of
groundwater .

Pesticide pathway entering water
 There are four major
routes through which
pesticides reach the
water: it may drift
outside of the intended
area when it is sprayed,
it may percolate, or
leach, through the soil,
it may be carried to the
water as runoff, or it
may be spilled, for
example accidentally or
through neglect. They
may also be carried to
water by eroding soil.

Soil pollution
The quality, i.e. fitness for use, resilience to change and ability
to recover, of Indian soils is getting gradually eroded at farm and
ecosystem level. The major threats to soil quality which involves
physical, biological and chemical properties, emerge from:
1. Loss of organic carbon
2. Erosion
3. Nutrient imbalance
4. Compaction
5. Salinization
6. Water logging
7. Decline in biodiversity
8. Urbanization
9. Contamination with heavy metals & pesticides
10. Adverse impact of climate change

Soil pollution
Deteriorated soil quality is affecting Indian agriculture adversely
through:
1. Yield loss
2. Low input use efficiency
3. Poor crop quality
4. Reduced farmer’s income & profitability
5. Environmental pollution
6. Climate change
 Nearly one third of rice-wheat farmers apply as much as 180 kg
fertilizer N ha-1 to each rice and wheat crop against the local
recommendation of 120 kg N ha-1.
 About 3.1 Mha of India’s agricultural land is waterlogged because of
inadequate drainage, improper balance in the ground water and
surface water use and seepage and percolation from unlined
channels. Agriculture and Environment33

 The problem of water logging in most serious in Haryana, Punjab,
West Bengal, Andhra Pradesh and Maharashtra.
 Stress due to salinity and alkalinity impair soil’s essential ecosystem
functions, resilience and ultimately soil quality.
 In saline soils, plant growth is affected because of accumulation of
salts in excess amount causing osmotic stress, toxic effect to some plants
and nutritional imbalance to some.
 About 4.1 Mha of India’s land is affected by salinity. It is serious
problem in Uttar Pradesh and Gujrat.
 The problem of alkali soils, on the other hand, is because of excess of
exchangeable sodium percentage (ESP).
 Alkalinity with high pH, excess ESP and high CaCO3 adversely
affects physical properties of the soil, prevent mineralization of organic
matter and causes volatilization loss of applied fertilizer N as NH3.
Soil pollution

Soil pollution through water erosion
35

Driving forces and threats affecting soil
quality and strategies for mitigation
Driving forces :
Socio-economic (Agriculture, transport, energy)
Ecological (Climate change, environmental pollution)
Function of soil :
1. Production of biomass 2. Physical structure
3. Filtering and buffering 4. Source of new material
5. Biological habitat 6. Geogenic and cultural habitat
Threats:
Loss of organic matter
Erosion
Nutrient imbalance
Compaction
Salinization
Decline in biodiversity
Contamination
Urbanization
Mitigation:
Carbon sequestration
Conservation Agriculture
Integrated Nutrient Mgt.
Erosion control
Diversification
Amelioration
Impact :
Yield loss
Poor crop quality
Pollution
Low input
efficiency
Reduced income
Climate change
36

Soil health
 Soil health is the
capacity of soil to
function within
ecosystem and land
use boundaries, to
sustain productivity
maintain
environmental
quality, and
promote plant and
animal health.

CHARACTERISTICS OF HEALTHY SOILS
 Good soil tilth.
 Sufficient depth.
 Sufficient but not excess of nutrients.
 Small population of plant pathogens and
insects.
 Good drainage.
 Large population of beneficial organisms.
 Low weed pressure.
 Free of chemicals and toxins
 Resistant to degradation.

Negative impacts of agrochemicals on soil health
 Kills beneficial organisms.
 Increase in nitrate levels of soils.
 Damage natural make up of soil.
 Alters the pH.
 Decrease soil quality.
 Poor soil physical condition.
 Toxic to microbes.
 Toxicity of nutrients.
 Kills earthworms.
 Growth regulators:
 Residual effect in agricultural commodies
 Toxic to soil organisms.

Fertilizer pollution
 Fertilizer use efficiency in Indian agriculture is quite low even with
good management practices.
Efficiency of N fertilizer use - 40 %
P use efficiency - 20 %
K use efficiency - 50 %
Micronutrient use efficiency - 2 %
 Many fertilizers, phosphate fertilizers, in particular, containing
varying amounts of trace elements such as arsenic (As), cadmium (Cd),
chromium (Cr), mercury (Hg), nickel (Ni) and lead (Pb).
 These harmful elements may accumulate in soil and cause long term
effects on the crop yield & quality and damage of soil microbes.
 through food and feed, they may also get into human and livestock
and cause health problems, if the accumulation exceeds the threshold
level.

42Imbalance use of fertilizers and other chemicals

Impaired soil health : Through the imbalance use of fertilizers and other
chemicals in agriculture affects the soil physical, chemical and biological
properties.

Impaired human health : The infamous incidences if “itai itai” and
“minamata” diseases due to cadmium and mercury toxicity, respectively, are the
examples of potential threat of heavy metal pollution.

Table : Environmental problems associated with fertilizer use and mitigation
strategies.
Environmental
problem
Causative mechanism Mitigation strategies
Ground water
contamination
Nitrate leaching Judicious use of fertilizers,
increasing efficiencies,
nitrification inhibitors, coated
fertilizer use
Eutrophication Erosion and surface run off Reduce surface run off, water
harvesting, controlled irrigation,
control erosion
Methaemoglobinemia Nitric acid originating from
reaction of N oxides with
moisture in atmosphere,
ammonia volatilization
Reduce ammonia volatilization
loss, decrease the pH of soil,
increase CEC, use fertilizer
formulations and inhibitors.
Stratospheric ozone
depletion
Nitrous oxide emission
from depletion and global
warming
Use of nitrification inhibitor and
soil urease inhibitor, increase N-
use efficiency

Persistent organic pollutants (POPs)
United Nations Environment Programme (UNEP) in 1995
identified 12 compounds, known as the ‘dirty dozen’ which included :
Organo-chlorine pesticides Industrial chemicals Industrial by-products
1. Aldrin Hexachlorobenzene
(HCB)
Dioxins
2. Chlordane Polychlorinated
biphenyl (PCB)
Furans
3. DDT
4. Dieldrin
5. Endrin
6. Heptachlor
7. Mirex
8. Toxaphene

POPs
 Nearly 60,000 tonnes of pesticides are entering the Indian
environment each year of which 1/3rd is used in public-health
programmes and 2/3rd in agriculture.
 The BHC, DDT and Malathion account for the bulk.
 Residues of some of the highly persistence pesticides (DDT, HCH,
Aldrin) have been found in various food, fodder, feed items.
 Part of applied pesticides, irrespective of crop, applicator or the
formulation, ultimately finds its way into the soil, water and food
chain.
 Long term effects of pesticides residues in the human body
include carcinogenicity, reduced life span & fertility, increased
cholesterol, high infant mortality and varied metabolic and genetic
disorders.

POPs
Persistence Half-life Pesticides
Non-persistent 1 – 2 weeks 2, 4-D, Diquat, Endothal
Slightly
persistent
2 – 6 weeks
Dicamba, Dalapan, EPTC,
Monuron, TCA
Moderately
persistent
<6 months
Atrazine, Monuron, Linuron,
Simazin, Terbacil, Trifluralin
Highly
persistent
>6 months DDT, HCH, Endosulfan, Aldrin
Table : Persistence of a few selected pesticides in soil.

Global level Agrochemical
consumption and use

POPs

Kerala’s Endosulfan tragedy
 The UNO classifies
Endosulfan as highly
dangerous insect killer
and banned in 62
countries.
 Endosulfan, a highly
toxic organochlorine
pesticide was sprayed
in the cashew
plantations in
Kasaragod District
sine 1976, till 2001
regularly three times
every year.

Air pollution
 Air pollution refers to the presence of various contaminants such as
gases, dust, fumes, mist, soot, tar, vapors and suspended particulate
matter in the air to the level which affects normal biological processes of
humans, animals, plants and other microorganisms or interfere with
comfortable enjoyment of life and property.
 The major air pollutants of concern in respect to agriculture are
sulphur dioxide (SO2), nitrogen oxides (NOx), hydrogen fluoride (HF),
peroxy acetyl nitrate (PAN), ozone (O3), hydrocarbon (HC), ethylene
(C2H4), ammonia (NH3) and suspended particulate matter (SPM).
 These gaseous pollutants and heavy metals enter plants mainly
through stomata and roots which disrupt photosynthetic, respiratory and
other biochemical and structural systems of plants and finally affect the
quantity and quality of crops with or without showing physiological
disorders.

Air pollution
 Compared to other cereals and food grain crops, vegetables are more
prone to gaseous and metallic pollutants as most of the vegetables are
succulents and physiologically more active.
 Another form of SO2 injuries appear on the plants resulting from its
conversion into acid rain and vegetables are more affected with it than
other crop plants.
 Amongst the vegetables, the leafy ones, such as spinach, fenugreek,
mustard, cauliflower and tomato are more affected as compared to hardy
vegetables viz., brinjal and beans.
 Mechanical threshing of crops, especially wheat, leads to increased
particulate matter in air which can cause respiratory diseases and aalergy
in rural areas.
 Burning of crop residues , such as rice straw in North-Western India,
also results in widespread air pollution. Asian brown cloud or haze is a
consequence of such a pollution.

 About 60 % and 82 % of rice straw produced in the North-
western stares of Haryana and Punjab, respectively, are
burned in the fields lading to release of soot particles and
smoke causing human health problems such as asthma,
emission of green house gases and loss of plant nutrients such
as N, P, K and S.
 Almost entire amounts of C and N, 25 % of P, 50 % of S
and 20 % of K present in straw are lost due to burning.
 Therefore burning of crop residues should be avoided and
alternate measures of disposal of residues should be found out.
Table : Threshold limits of different air pollutants on vegetation
Air pollution
Pollutants SO2 O3 PAN NOx HF C2H4 NH3
Threshold
(ppm)
0.3 0.04 0.01 2.5 0.0001 0.05 10 - 20

Effect on air
 Pesticides can contribute to
air pollution.
 Pesticide drift occurs when
pesticides suspended in the
air as particles are carried
by wind to other areas.
 Weather conditions at the
time of application as well as
temperature and relative
humidity change the spread
of the pesticide in the air.

 Low relative
humidity and high
temperature result
in more spray
evaporating.
 The polluted air is
inhaled by humans
end with up with
different diseases.

 The aerial spraying of
Endosulfan was allegedly
undertaken to contain the
menace of the tea
mosquito bug.
 By 1990s health disorders
of very serious nature
among the human
population came to the
lime light.
 Children were found to be
the worst affected with
congenital anomalies,
mental retardation,
physical deformities,
cerebral palsy, epilepsy
etc
58

Air pollution

Ozone pollution
 Ozone is deposited on the plant canopies, enters the leaf through
stomata and decreases net photosynthesis via oxidative damage to
cell membranes, especially to chloroplasts and consequently reduces
dry matter production.
 Noticeable effects of ozone pollution to the leaves of the crops
include changes in shape , discoloration and necrosis.
 Reduction in nutrient content of vegetable crops (Fe in spinach &
β-carotene in carrot) is also observed.
 Ozone has a significant climate change impact by adversely
affecting plant’s ability to remove CO2 from the atmosphere by
reducing CO2 uptake leading to more accumulation of CO2 in the
atmosphere.

Loss of biodiversity
 India is endowed with diverse ecosystems as tropical rain forests,
temperate forest, alpine vegetation, wetlands and mangroves.
However, some reasons are responsible for loss of bio-
diversity
1. Over-exploitation,
2. Habitat destruction,
3. Pollution and
4. Species extinction
 Continuous use of fertilizers & pesticides, mechanization,
monoculture, adoption of limited number of high-yielding crop
varieties and hybrids, limited crops and farm animal diversification
in the last few decades have gradually led to the genetic and species
erosion in some agricultural lands.
 Increasing use tractors in agriculture and transportation has
resulted in losses of cattle diversity and population in our country.

Environmental risk from genetically modifies organisms (GMOs)
 Herbicide tolerance (HT) and insect resistance (Bt) have been
successfully engineered into corn, cotton, soybeans and canola.
 In India, so far, only Bt cotton is approved for this purpose.
The environmental risk due to releasing of GMOs could be due
to:
1. Risk invasiveness
2. Direct and indirect non-target effects on beneficial and
native organisms
3. Occurrence of new viral diseases
4. Loss of crop bio-diversity
 Transgenic plants can also increase removal of toxic heavy
metals from polluted soil & water and sequester these into plant
tissue, or can transform pollutions into less toxic forms.

Human health
 Direct effect
 Indirect effect
Air
Water
Food chain
Ingestion

 Pesticides can enter the body
through inhalation of aerosols,
dust and vapour that contain
pesticides; through oral exposure
by consuming food/water; and
through skin exposure by direct
contact.
 The effects of pesticides on
human health depend on the
toxicity of the chemical and the
length and magnitude of
exposure.
 Farm workers and their family
experience the greatest exposure
to agricultural pesticides through
direct contact.
Pesticides entering human body

 Pesticide exposure can
cause a variety of adverse
health effects, ranging
from simple irritation of
the skin and eyes.
 It also affects the
nervous system, mimicking
hormones causing
reproductive problems,
and also causing cancer.
 Children are more
susceptible and sensitive
to pesticides, because
they are still developing
and have a weaker immune
system than adults.

The ideal pesticide and the nightmare
insect pest
 The ideal pest-killing chemical has
these qualities:
 Kill only target pest.
 Not cause genetic resistance in the
target organism.
 Disappear or break down into harmless
chemicals after doing its job.
 Be more cost-effective than doing
nothing. It would stay exactly where it
was put and not move around in the
environment.
 There is no such thing!

Environmental Impact Assessment (EIA)
 To assess the environmental impact of agriculture on the
scale of farming region, six methods are used depending on
the objectives :
1. Environmental risk mapping
2. Life cycle analysis
3. Environmental impact assessment
4. Multi-agent system
5. Linear programming
6. Agro-environmental indicators

Indices for Environmental Monitoring
1. Air quality index (AQI)
2. Biocide residue index (BRI)
3. Ecological footprint
4. Environmental sustainability index (ESI)
5. Environmental performance index (EPI)
6. Environmental vulnerability index (EVI)
7. Global warming potential (GWP)
8. P index
9. T value (Soil loss tolerance)
10. Soil quality indicator (SQI)
11. Soil sustainability index (SSI)
12. Soil threat index (STI)
13. Sustainable yield index (SYI)
14. Water quality index

Impaired environment can be restored by some
tools :
1. Carbon sequestration
2. Conservation agriculture
3. Crop diversification
4. Amelioration of polluted environment
5. Renewable source of energy
6. Bio-diesel crops
7. Agricultural waste management
Environmental restoration

Environmental restoration
Carbon sequestration :
 Organic carbon content of soil is the single most important parameter
affecting soil quality. Therefore, carbon sequestration has high potential
in improving soil quality.
 Besides, it reduces GHGs emission, environmental pollution and
enhancing bio-diversity resulting in increased productivity.
 Carbon can be sequestered in soil by increasing C input and/or
decreasing their decomposition.
 Soil management strategies for carbon sequestration include three
approaches :
1. Management of soils to maintain existing levels of organic
matter such as reduced tillage and no tillage practices.
2. To manage carbon degraded soils to restore depleted soil
organic matter level. Wastelands in India are over 100 Mha of which 70
% are carbon degraded.
3. To manage soils to enlarge soil organic matter pools by
improving soil fertility. Agriculture and Environment72

Carbon sequestration :
 Increase in SOC by 1 Mg ha-1 can result in increase in grain yield by
30 – 50 kg ha-1 of rice, wheat, millets and beans and 100 – 140 kg ha-1 of
maize and sorghum with adoption of appropriate soil and crop
management practices.
Table : Extend of soil degradation in India and potential of carbon
sequestration in these soils, if restoration is undertaken
Degradation Area (Mha) SOC sequestration
potential (Tg/yr)
Water erosion 32.8 2.6 – 3.9
Wind erosion 10.8 0.4 – 0.7
Soil fertility decline 29.4 3.5 – 4.4
Water logging 3.1 0.1 - 0.2
Salinization 4.1 0.5 – 0.6
Desertification 68.1 2.7 – 4.1
Total 148.3 9.8 – 13.9

Conservation Agriculture
 CA that features little or no soil disturbance,
no burning of crop residues,
direct seeding into previously untilled soil,
crop rotations,
permanent soil cover particularly through the
retention of crop residues has made considerable progress in the USA,
Latin America, Australia, China and South & Central Asia.
 In India, Resource conservation technologies (RCTs) involving zero
or minimum tillage with direct seeding and bed planting with residue
mulch are being advocated as the alternatives to the conventional rice-
wheat systems and for improving sustainability.
 The RCTs are more resource efficient : reduced nutrient loss,
increased soil organic C content, use less inputs, improved production
and income and reduced GHG emission compared to the conventional
practices

Table : Potential benefits of RCTs in terms of agriculture sustainability and
climate change mitigation relative to conventional practices
RCTs Potential benefits relative to conventional practices
Zero tillage Reduce water use, C sequestration, increased yield and income,
reduced fuel consumption, reduced GHG emission, more
tolerant to heat stress
Laser-aided land leveling Reduced water use, more efficient tractor use, reduced fuel
consumption, reduced GHG emission, increased area for
cultivation
Direct drill seeding to rice Less requirement of water, saves time, post harvest condition
of field is better for succeeding crop, deeper root growth and
better tolerance to water and heat stress, reduced methane
emission
Diversification Efficient use of water, increased income, increased nutritional
security, conserve soil fertility, reduced risk
Raised bed planting Less water use, improved drainage, better residue management,
less lodging of crops, more tolerant to water stress
Leaf colour chart (LCC) Reduced N fertilizer requirement, reduced N loss, and
environmental pollution, reduced N2O emission

Crop diversification
 Diversification i.e. growing a range of crops suited to different
sowing and harvesting times, assists in achieving sustainable
productivity by allowing farmers to employ biological cycles to
minimize inputs , maximize yields, conserve resource base and
reduce risk from both environmental and economic factors.
 To reserve the downward trend of sustainable productivity,
substantial change in the current cropping system is required,
including reducing tillage and improving organic matter status.
 Fortunately, the farmers of the rice-wheat belt have take taken
the initiative to diversify their farming systems by including short
duration crops e.g. potato, soybean, moongbean, cowpea, pea,
mustard and maize in different combinations.

Pollution amelioration
 Environment (soil & water) polluted by substances hazardous to plant
growth and human can be rectified by bio-remediation i.e. using
biological agents to reclaim soil and water.
 Microbes are generally useful for assisting in reclamation of sites with
heavy metal problems. Several fungi are also good in accumulation of
heavy metals, Cd, Cu, Hg, Pb, Zn & others. Rhizopus arrhizus is, for
example, useful in treating uranium and thorium.
 Higher terrestrial plants can also be used for environmental
restoration, the process called phyto-remediation.
 The ability of fungi to transform a wide variety of hazardous
chemicals has aroused interest in using them in bio-remediation. The
fungi are unique among microorganisms because they secrete a variety of
extra-cellular enzymes that facilitate decomposition of some pollutants
like Pentachlorophenyl and creosote in soil.
 Bacteria are also good degraders of toxic pesticides such as
halocarbons. Agriculture and Environment77

Renewable sources of energy
 Renewable energy sources are the important means of supplementing
conventional fossil fuels, which are invariably accompanied with
environmental problems of local and global dimensions.
 Bio-fuel including wood fuel, charcoal, biogas, ethanol, agriculture
waste, crop residues and energy crops have been considered as the
sources, which could be used as substitute to the environment fuel.
 The liquid biofuel , usually in the form of alcohol, can be produced
from the plant carbohydrates after enzymatic hydrolysis and
fermentation. Unlike fossil fuels, ethanol is a renewable energy source
produced through fermentation of sugar
 Although fungi, bacteria and yeast can be used for fermentation and
commonly used to ferment glucose to ethanol in the bakery.
 Theoretically, 100 g of glucose will produce 51.4 g of ethanol (Net
gain of <48 g ethanol/ 100 g glucose) and 48.8 g of carbon dioxide.

Bio-diesel
 Non edible oil from Jatropha curcas (Ratanjot) and Pongamia
pinnata (Karanj) can also be used for biodiesel production. The Jatropha
seeds contain 30 – 35 % of non edible oil. However, commercial
viability of Jatropha cultivation is yet to be established.
 Oil from crops such as rapeseed & mustard, sunflower, olive,
soybean, canola, cotton seed, palm, coconut, peanut and jojoba can be
used for biodiesel production.
 Currently, soybean is the primary feedstock in the US for biodiesel
production.
 Another feedstock for biodiesel is aquatic unicellular green algae with
high growth rate and high oil content (over 50 %). Under good
conditions these algae can double their biomass in less than 24 hours.

Agricultural waste management
 Agricultural residues are generally considered as wastes. Some of these
residues though are used for cattle feed, livestock bedding, thatching material for
houses and a source of domestic energy.
 The remaining residues are generally left unattended as such to decompose or
sometimes even burnt.
 Such practices not only result in waste of the nutrients in the residues but also
contribute to air pollution and global warming.
 Fruits, vegetable, sugar, paper and pulp industries leave lot of crop residues,
which need to be disposed of. Since demand of processed food is increasing, in
future more such wastes will be generated.
 Typically biogas evolved from cattle dung based plant is composed of (by
volume) 50 – 60 % methane, 30 – 40 % CO2, 0.5 – 1 % hydrogen, and 4 – 6 %
nitrogen.
 The anaerobically digested slurry produced from biogas plant contains 1.4 –
1.8 % N, 0.4 – 0.8 % P, 0.7 – 1.0 % K, 20 – 25 % organic carbon, 1 – 3 % Ca, 1 –
2 % Mg and about 1 % S with a C:N 15 – 20.

Initiatives for combating Global Environment Change
Organization
United Nations Environment Programme (UNEP), 1972 (Nairobi, Kenya)
 Inter-Governmental Panel on Climate Change (IPCC), 1988 (Washington, DC)
 World Meteorological Organization (WMO), 1950 Geneva (Switzerland)
 United Nation Framework Convention on Climate Change (UNFCCC),
 The United Nations Conference on Environment and Development (UNCED), 3-14 June, 1992, Rio de Janeiro
 Global Environment Facility (GEF)
Environmental legislation
 The Water (Prevention and Control of Pollution) Act, (1974)
 The Air (Prevention and Control of Pollution) Act, (1981)
 The Environment (Protection) Act, (1986)
 The Air (Prevention and Control of Pollution) Amendment Act, (1987)
 Hazardous Waste (Management and Handling) Rules, (1989)
 The Municipal Solid Wastes (Management and Handling) Rules, (2000)
 The Ozone Depleting Substances (Regulation and Control) Rules, (2000)
 The Biological Diversity Act, (2002)

Table : 1 Growth parameters of Abelmoschus esculentus (okra plant) by the
combination of different treatments.
Treatment
72 Days after sowing (Mean + SD)
Plant height
Stem
circumstances
(mm)
No. of leaves
per plant
T1 Control 62.1 + 0.7 2.0 + 0.05 10.6 + 0.5
T2 FYM 100 % 64.2 + 0.4 2.3 + 0.05 11.6 + 0.5
T3 VC 100 % 69.7 + 0.1 2.5 + 0.05 12.8 + 0.2
T4 CF 100 % 73.1 + 0.2 3.0 + 0.05 15.6 + 0.1
T5 VC 75 % + CF 25 % 72.0 + 0.1 2.6 + 0.05 13.6 + 0.5
T6 VC 75 % + FYM 25 % 68.5 + 0.3 2.5 + 0.05 12.6 + 0.5
T7 VC 50 % + FYM 50 % 66.9 + 0.5 2.4 + 0.05 12.3 + 0.2
T8 VC 50 % + CF 50 % 70.1 + 0.3 2.8 + 0.05 14.6 + 0.5
P value >0.05 >0.05 >0.05
Significance S S S
Jalgaon, Maharashtra Attarde et al., 2012

Table : 2 Post harvest parameters of Abelmoschus esculentus (okra plant)
by the combination of different treatments.
Treatment
72 Days after sowing (Mean + SD)
Fresh plant
(g)
Dry plant
(g)
Fresh pods
(g)
Dry pods
(g)
T1 Control 51.5 + 0.2 10.7 + 0.5 15.4 + 0.4 1.1 + 0.1
T2 FYM 100 % 56.0 + 0.2 15.9 + 0.3 22.1 + 0.4 1.6 + 0.05
T3 VC 100 % 68.0 + 0.1 18.5 + 0.3 25.5 + 0.5 2.4 + 0.1
T4 CF 100 % 72.4 + 0.1 21.3 + 0.6 18.2 + 0.2 1.3 + 0.05
T5 VC 75 % + CF 25 % 63.8 + 0.1 16.0 + 0.4 20.2 + 0.5 1.7 + 0.05
T6 VC 75 % + FYM 25 % 59.5 + 0.4 16.8 + 0.3 24.6 + 0.3 2.1 + 0.05
T7 VC 50 % + FYM 50 % 58.9 + 0.7 13.8 + 0.8 23.1 + 0.3 1.8 + 0.05
T8 VC 50 % + CF 50 % 60.7 + 0.4 15.1 + 0.2 19.4 + 0.7 1.4 + 0.05
P value >0.05 >0.05 >0.05 >0.05
Significance S S S S
Jalgaon, Maharashtra Attarde et al., 2012

Table : 3 Mean variables of cowpea (V. unguiculata) and common bean (P. vulgaris)
in function of different fertilizations.
Treatment
Plant height
(cm)
Stem diameter
(mm)
Chlorophyll
a
Chlorophyll
b
Total
chlorophyll
Leaf biofertilizer 35.17 9.76 35.17 9.76 44.94
Organic compost 37.95 11.59 37.95 11.59 49.55
Mineral fertilizer 35.22 8.99 35.22 8.99 44.22
Without fertilizer 34.59 9.02 34.59 9.02 43.61
Mean 35.73 9.84 35.73 9.84 45.58
CV (%) 6.86 18.62 6.86 18.62 8.35
Brazil Cavalcante et al., 2016

Table : 4 Mean variables of cowpea (V. unguiculata) and common bean (P. vulgaris)
in function of different fertilizations.
Treatment No. of pods
No. of seeds/
pod
Pod length
(cm)
100 seed
weight (g)
Productivity
(kg ha-1)
Leaf biofertilizer 21.18 14.44 14.44 21.18 2355.78
Organic compost 21.42 14.65 14.65 21.42 3060.00
Mineral fertilizer 8.27 14.57 14.57 8.27 2779.57
Without fertilizer 18.07 13.03 13.03 18.07 2145.28
Mean 17.23 14.17 14.17 17.23 2585.16
CV (%) 11.34 5.84 5.84 11.34 18.82
Brazil Cavalcante et al., 2016

Table : 5 Effect of chemical fertilizer and bio fertilizer on plant height (cm) and no. of
grains per plant of rice.
87
Allahabad, India Alam & Seth, 2012
Treatment Pot No. Plant height (cm) Avg. plant height
(cm)
No. of grains/plant Avg No. of
grains/plant
No Treatment
(Pot Control)
1 78.5
78.7
271
244
2 79.0 222
3 75.0 145
4 79.5 189
5 81.5 395
Chemical
Fertilizer
(NPK)
6 81.0
84.7
594
610
7 87.5 670
8 85.0 480
9 83.0 617
10 87.0 691
Bio-fertilizer
(BGA)
11 96.5
91.8
910
893
12 82.0 791
13 94.0 1009
14 91.0 989
15 95.5 769

Table : 6 Grain yield (kg ha-1) of rice across biological and chemical fertilizers.
88
Lahijan, Iran Azin Nasrollah Zadeh, 2014
Treatments Ist year IInd year Average
Biological fertilizer (M)
No Fertilizer (M1) 2924 2972 2948
10 ton/ ha cow dung (M2) 2854 3050 2952
20 ton/ ha cow dung (M3) 3081 2879 2980
5 ton/ ha azolla compost (M4) 3440 3334 3387
Mean 3074.75 3058.75 3066.75
Chemical fertilizers (S)
No fertilizer (S1) 2408 2638 2523
40 kg N/ha (S2) 3158 2982 3070
60 kg N/ha (S3) 3314 3258 3286
80 kg N/ha (S4) 3420 3326 3373
Mean 3075 3051 3063

Conclusion
1._Organic substitutes viz. FYM, manures, composts, verm-icomposts, biofertilizers,
green manures in organic farming found better for both the dimensions ecology (safe to
atmosphere, soil and human health) as well as for economy after 1 or 2 years.
2. Conservation agriculture is proposed safe and conserving the available natural
resources through stubble mulch (soil cover), zero / minimum tillage and better
utilization of agriculture waste materials.
3. Maximum utilization of eco-friendly fuel substitutes viz. biodiesel and biogas for the
reduction of hazardous chemical emission in the ecosystem.
4. Crop should be diversified land fallow should be kept in the cropping system suitable
to the particular ecosystem based on the local demands.
5. Organic matter should be incorporated timely for the better soil biology, chemistry
and physics.
6. Phyto-remediation - problematic soils can be remedised with the help of augmentation
of microbes, organic matter and vegetation over soil.
7. Integration of available farm enterprises can be implemented for the conservation
and better utilization of available natural resource without impairment to ecology and
economy.

Is it really possible to grow
crops without agrochemicals ?

Deshraj Singh Suman

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