sustainable agriculture

Farming Systems and

Sustainable Agriculture

INTRODUCTION TO SUSTAINABLE AGRICULTURE

        Over the history of human settlements on the planet earth,

agriculture has transformed in tune with the growing population and its

challenging needs. The transformation has been quite remarkable since

the end of World War  II. Food  and fibre productivity spared up due to

adoption of new technologies viz, HYV, from mechanization, increased

fertilizer & pesticide use, specialized farming  practices, water resource

development & improved irrigation practices and Government policies

that favored maximizing  production. It was in the early 1960s, the Green

Revolution took shape in developing countries, especially India. It led to

the attainment of self- sufficiency in food grain production. This has

been described by Donald plunkett (1993), scientific adviser to the

CGIAR, as the greatest agricultural transformation in the history of

humankind, and most of it has taken place during our lifetime. The

change was brought about the rise of Science-based agriculture which

permitted higher and more stable food production, ensuring food stability

and security for a constantly growing world population’. A major

problem was that these benefits have been poorly distributed’. Many

people have missed out and hunger still persists in many parts of the

world.  Estimates by the FAO and WHO (1992) and the Hunger Project

(1991) suggest that around 1 billion people in the world have diets that

are ‘too poor to abstain the energy required for healthy growth of

children and minimal activity of adults’. The causes are complex and it is

not entirely the fault of overall availability of food. Nonetheless, the

process of agricultural modernization has been an important contributing

factor, in that the technologies have been more readily available to the

better-off.

    Modern agriculture begins on the research station, where researchers

have access to all i.e., necessary inputs of fertilizers, pesticides and

labour at all the appropriate times. But when the package is extended to

farmers, even the best performing farms cannot match the yields the

researchers get. For high productivity per hectare, farmers, need access

to the whole package – modern seeds, water, labour, capital or credit,

fertilizers and pesticides. Many poorer farming households simply

cannot adopt the whole package. If one element is missing, the seed

delivery system fails or the fertilizer arrives late, or there is insufficient

irrigation water, then yields may not be much better than those for

traditional varieties. Even if farmers want to use external resources, very

often delivery systems are unable to supply them on time.

     Where production has been improved through these modern

technologies, all too often there have been adverse environmental and

social impacts in both the advanced and developing countries including

India. These include the following:

 Adverse effects of modern high- input agriculture           

• Overuse of natural resources, causing depletion of groundwater,

and loss of forests, wild habitats, and of their capacity to absorb

water, causing waterlogging and increased salinity:

• Contamination of the atmosphere by ammonia, nitrous oxide,

methane and the products of burning, which play a role in ozone

depletion, global warming and atmospheric pollution:

• Contamination of food and fodder by residues of pesticides,

nitrates and antibiotics.

• Contamination of water by pesticides, nitrates, soil and livestock

water, causing harm to wildlife, disruption of ecosystems and

possible health problems in drinking water;

• Build up of resistance to pesticides in pests and diseases

including herbicide resistance in weeds

• Damage of farm and natural resources by pesticides, causing

harm to farm workers and public, disruption of ecosystems and

harm to wildlife.

•  Erosion of genetic diversity – the tendency in agriculture to

standardize and specialize by focusing on modern varieties,

causing the displacement of traditional varieties and breeds:

•  New health hazards for workers in the agrochemical and foodprocessing

industries

Added  to the above adverse effects, the increasing human as well as

cattle population is imposing intense pressure on available natural

resources. Accordingly, a challenge has emerged that required a new

vision, holistic approaches for ecosystem management and renewed

partnership between science and society.

        In December 1983, the UN General Assembly established the

World Commission on Environment and Development. In 1987, on  27

of April, at the queen Elizabeth Hall in London, the Prime  Minister of

Norway, Mrs. Brundtland, who is also the Chairman of the World

Commission of Environment and development, released the publication

of “ Our Common Future” by the World Commission on Environment

and Development (WCED) and said: “ Securing our common future will

require new energy and openness, fresh insights, and an ability to look

beyond the narrow bounds of national frontiers and separate Scientific

disciplines. The young are better at such vision than we, who are too

often constrained by the traditions of former, more fragmented World.

We must tap their energy, their openness, their ability to see the

interdependence of issues…” She suggests that we must adopt a new

paradigm based on a completely new value system. “ Our generation has

too often been willing to use the resources of the future to meet our own

short- term goals. It is a debt we can never repay. If we fail to change our

ways, these young men and women will suffer more than we, and they

and their children will be denied their fundamental right to a healthy

productive, life-enhancing environment.” Her speech made it clear that

we are consuming resources, which must be transferred to the next

generation. We must recognize that, because resources are limited, we

need a sustainable way of life.

       Almost at the same time the realization of prime importance of

staple food production for achieving food security for future generations

has brought the concept of “Sustainable Agriculture” to the forefront and

began to take shape in the following three points.

1. The interrelatedness of all the farming systems including the       

farmer and the family.

2. The importance of many biological balances in the system.  

3. The need to maximize desired biological relationships in the system

and minimize the use of materials and practices that disrupt these

relations. 

Sustainability of agricultural systems has become a global concern today

and many definitions so Sustainable Agriculture have become available.

  Definition of Sustainable Agriculture

Sustainable Agriculture refers to a range of strategies for addressing

many problems that effect agriculture. Such problems include loss of soil

productivity from excessive soil erosion and associated plant nutrient

losses, surface and ground water pollution from pesticides, fertilizers and

sediments, impending shortages of non- renewable resources, and low

farm income from depressed commodity prices and high production

costs. Furthermore, “Sustainable” implies a time dimension and the

capacity of a farming system to endure indefinitely.                   

                                                                                                                                        

(Lockertz, 1988)

The successful management of resources for agriculture to satisfy

changing human needs while maintaining or enhancing the (Natural

resource- base and avoiding environmental degradation)                  

(TAC-CGIAR, 1988)  

A sustainable Agriculture is a system of agriculture that is committed to

maintain and preserve the agriculture base of soil, water , and

atmosphere ensuring future generations the capacity to feed themselves

with an adequate supply of safe and wholesome food’                  

(Gracet,  1990)

‘A Sustainable Agriculture system is one that can indefinitely meet

demands for food and fibre at socially acceptable, economic and

environment cost’

         (Crosson, 1992)

A broad and commonly accepted definition of sustainable

Agriculture is as follows:

Sustainable Agriculture refers to an agricultural production and

distribution system that:

• Achieves the integration of natural biological cycles and controls

• Protects and renews soil fertility and the natural resource base

• Reduces the use of nonrenewable resources and purchased 

( external or off-farm) production inputs

• Optimizes the management and use of on- farm inputs

• Provides on adequate and dependable farm income

• Promotes opportunity in family farming and farm communities,

and

• Minimizes adverse impacts on health, safety, wildlife, water

quality and the environment       

 Current concept of sustainable agriculture

 A Current concept of sustainable Agriculture in the United States

showing the ends and the means of achieving them through low- input

methods and skilled management is shown in Fig.1.1.

    The ultimate goal or the ends of sustainable agriculture is to develop

farming systems that are productive and profitable, conserve the natural

resource base, protect the environment, and enhance health and safety,

and to do so over the long-term. The means of achieving this is low input

methods and skilled management, which seek to optimize the

management and use of internal production inputs (i.e., on-farm

resources) in ways that provide acceptable levels of sustainable crop

yields and livestock production and result in economically profitable

returns. This approach emphasizes such cultural and management

practices as crop rotations, recycling of animal manures, and

conservation tillage to control soil erosion and nutrient losses and to

maintain or enhance soil productivity.

Low-input farming systems seek to minimize the use of external

production inputs (i.e., off-farm resources), such as purchased fertilizers

and pesticides, wherever and whenever feasible and practicable: to lower

production costs: to avoid pollution of surface and groundwater: to

reduce pesticide residues in food: to reduce a farmer’s overall risk:; and

to increase both short-term and long-term farm profitability. Another

reason for the focus on low- input farming systems is that most highinput

systems,

sooner or later,

would probably fail because they are not

either

economically

or environmentally

sustainable over the long-term.

p

Productive and

Profitable

Conserves

Resources and

protects the

environment

Low input

methods and

skilled

management

 

_____________________________________________________

1. Reduceduse of synthetic                7. Crop rotations

2. chemical inputs                          8.Use of Organic wastes

3. Biological pest control                    9.Crop- livestock  

                                                     diversification

    

Enhances health

and safety

4. Soil and water conservation

practices 

                                                10.  Mechanical cultivation                         

5. Use of animal and green             11. Naturallyoccurring

manures

                                          processes                                                              

6. Biotechnology                                                                                 

   

 Goals of sustainable Agriculture

A sustainable Agriculture, therefore, is any system of food or fiber

production that systematically pursues the following goals:

• A more thorough incorporation of natural processes such as

nutrient cycling nitrogen fixation and pest-predator relationships

into agricultural production processes:

• A reduction in the use of those off-farm, external and nonrenewable

inputs

with the greatest potential to damage the

environment

or harm the health of

farmers and consumers,

and

more

targeted

use of the remaining

inputs used with a view to

minimizing

variable costs:

• The full participation of farmers and rural people in all processes

of problem analysis and technology development, adoption and

extension.

• A more equitable access to predictive resources and opportunities,

and progress towards more socially just forms of  Agriculture:

• A greater productive use of the biological and genetic potential of

plant and animal species:

• A greater productive use of local knowledge and practices,

including innovation in approaches not yet fully understood by

scientists or widely adopted by farmers:

• An increase in self-reliance among farmers and rural people

• An improvement in the match between cropping patterns and the

productive potential and environmental constraints of climate and

landscape to ensure long-term sustainability of current production

levels: and 

• Profitable and efficient production with an emphasis on integrated

form management: and the conservation of soil, water, energy and

biological resources

 Elements of sustainability

 There are many ways to improve the sustainability of a given

farming system, and these vary from region to region, However, there

are some common sets of practices among farmers trying to take a

more sustainable approach, in part through greater use of on-farm or

local resources  each contributing in some way to long- term

profitability, environmental stewardship and rural quality of life.

a) Soil conservation- Many soil conservation methods, including

contour cultivates contour bunding, graded bunding, vegetative barriers,

strip cropping cover cropping, reduced tillage etc help prevent loss of

soil due to wind and water  erosion

 b) Crop diversity- Growing a greater variety of crops on a farm can

help reduce risks from extremes in weather, market conditions or crop

pests. Increased diversity crops and other plants, such as trees and

shrubs, also can contribute to soil conservation, wildlife habitat and

increased populations of beneficial insects

c) Nutrient management- Proper management of nitrogen and other

plant nutrients con improve the soil and protect environment. Increased

use of farm nutrient sources such as manure and leguminous cover crops,

also reduces purchased fertilizer costs.

d) Integrated pest management (IPM)- IPM  is a sustainable approach

to managing pests by combining biological, cultural, physical and

chemical tools in way that minimizes economic, health and

environmental risks.

e) Cover crops- Growing  plant such as sun hemp, horse gram,

pillipesara in the off season after harvesting a grain or vegetable crop can

provide several benefits, including weed suppression, erosion control,

and improved soil nutrients and soil quality .

f) Rotational grazing- New management- intensive grazing systems

take animals out barn into the pasture  to provide high-quality forage and

reduced feed cost .

g) Water quality & water conservation- Water conservation and

protection have important part of Agricultural stewardship. Many

practices have been develop conserve Viz., deep ploughing, mulching,

micro irrigation techniques etc.., protect quality of drinking and surface

water .

h) Agro forestry- Trees and other woody perennials are often

underutilized on ----covers a range of practices Viz., ogi-silvicuture,

silive-pastoral, agri-silvi-pagri-horticulture, horti/silvipastoral, alley

cropping, tree farming , lay farm that help conserve, soil and water.

i) Marketing- Farmers across the country are finding that improved

marketing -----way to enhance profitability, direct marketing of

agricultural product from farmers to consumers is becoming much more

common, including through Rythu bazaar rod side stands .

 Status of sustainable Agriculture in India

     The survival and well being of the nation depends on sustainable

development. It is a process of social and economic betterment that

satisfy needs and values of interest groups without foreclosing options.

Suitable Development of India demands access to state of are ‘clean’

technologies and have as strategic role in increasing the capabilities of

the country both o the environment as well as to provide thrust towards

conservation and sustainable agriculture. Current research programmes

towards sustainable agriculture are as follows:

1. Resistant crop varieties to soil, climatic and biotic stresses

2. Multiple cropping system for irrigated areas and tree based

    farming system rainfall area.

3. Integrated nutrient management

a. Combined use of organic and inorganic sources of   

      nutrients

b. Use of green manures (Sesbania, Crotalaria etc)

c. Inclusion of pulse crops in crop sequence

d. Use of bio fertilizers

4. Integrated pest management

a. Microbial control

b. Use of botanicals

c. Use of predators

5. Soil and water conservation

a. Watershed management

b. Use of organics as mulch and manure

c. Use of bio-fencing like vettiver

6. Agroforestry systems in dry lands/ sloppy areas and erosion prone 

areas

7. Farm implements to save energy in agriculture

8. Use of non-conventional energy in Agriculture

9. Input use efficiency

a. Water technology

b. Fertilizer technology

10. Plant genetic resource collection and conservation.

      ***

FACTORS AFFECTING ECOLOGICAL BALANCE AND

SUSTANABILITY OF AGRICULTURAL RESOURCES

  Technology generated and implemented for increasing

Agricultural productivity during past three decades resulted in depletion

of natural resource base besides creating several environmental and

ecological problems. In contrast the demand scenario features a growth

rare in food requirements to meet the ever-increasing demand of the

growing population. The total food grain demand of India by 2020 is

estimated at 294 million tones as against the present 224 million tonnes

(2010-11), which has to come from the almost static net cultivated area

of about 142 million ha. This improvement in food grain production has

to be achieved while dealing with the factors affecting the ecological

balance and sustainability of Agricultural resources.

Major factors affecting the ecological balance and sustainability of

agricultural resources are:

a) Land/soil related problems 

• Soil degradatiom

• Deforestation

• Accelerated soil erosion

• Siltation of reserves

• Wind erosion

b) Irrigation related problems

• Rise in groundwater table & water logging

• Soil salinization & alkalization

• Over- exploitation of groundwater 

c) Indiscriminate use of agro-chemicals

• Fertilizer pollution

• Pesticide pollution

d) Environmental pollution

• Greenhouse effect

• Depletion emissions

• Methane emission

• Eutrophication

e) Erosion of genetic biodiversity

 Land/soil related problems

 Soil degradation

Soil degradation refers to decline tin the productive capacity of land due

to decline in soil quality caused through processed induced mainly by

human activities. It is a global problem. The Global Assessment of the

Status of Human-induced soil Degradation (GLASOD) was the first

worldwide comparative analysis focusing specifically on soil

degradation. Worldwide  around 1.96. Billion ha are affected by human-

induced soil degradation, mainly caused by water and wind erosion

(1094 and 548 million ha respectively). Chemical degradation accounted

for 240 million ha, mainly nutrient decline (136 million ha) and

salinization (77 million ha), physical degradation occurred on 83 million

ha, mainly as a result of compaction, sealing and crusting.

It is also a very important problem in India, which shares only 2.4% of

the world’s land resource and supports more than 18% of the world’s

human population and 15% of livestock population. Estimates of soil

degradation are varied depending upon the criteria used.

The soil degradation through different processes is shown in Fig.2.2. The

processes leading to soil degradation are generally triggered by excessive

pressure on land to meet the competing demands of growing population

for food, fodder, fibre and fuel.

Therefore, the direct causes for soil degradation are unsustainable land

use and inappropriate land management. The most common direct causes

include:

  

• Deforestation of fragile lands

• Over cutting and grazing of vegetation

• Extension of cultivation on to lands of low

 capability/potential

• Improper crop rotations

• Unbalanced fertilizer use

• Non-adoption of soil conservation practices

• Inadequacies in planning and management of irrigation resources

• Overdraft of groundwater in excess of capacity to recharge

The strategies for improving soil quality and sustainability include –

skilled management, crop rotation, soil and water conservation,

conservation tillage integrated nutrient management, integrated water

management, integrated pest management and integrated ( crop &

livestock system) farming systems, 

Soil degradation

Physical

Chemical

Compaction

& crusting

Desertification

Erosion and

depletion

Water Wind

Fertility

imbalance

Elemental

Acidification Salinisation

and

alkalization

 Soil degradation through different processes

Biological

Decline in

OM

Toxicant

accumulation

 Soil degradation through different

processes

 Reduction

in macro &

micro

fauna

Wind Erosion

Water erosion