Farming system and environment - Hill Agrichillagric.ac.in/edu/coa/agronomy/lect/agron-4711/Lecture 11 Farming... · agricultural practices will help in addressing socio-economic

LECTURE 1 1

Farming system and environment

SS RANA

SR SCIENTIST

Major issues

� Food security, livelihood security, water security, naturalresources conservation and environment protection,climate change and globalization have emerged as majorissues worldwide.

� Sustainable development is the only way to promoterational utilization of resources and environmentalprotection without hampering economic growth.

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rational utilization of resources and environmentalprotection without hampering economic growth.

� Promoting sustainable development through sustainableagricultural practices will help in addressing socio-economic as well as environmental issuessimultaneously.

� Within the broad concept of sustainable agriculture"Integrated Farming Systems" hold special position.


Integrated farming systems: Environmental Sustainability in Full Circle

� In farming system an inter-related set ofenterprises is taken up so that the “waste”from one component becomes an input foranother part of the system.

� Since it utilizes wastes as resources, we not only

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� Since it utilizes wastes as resources, we not onlyeliminate wastes but we also ensure overall increasein productivity for the whole agricultural systems.Also wastes as resource reduces cost of productionand increase income of the farmer.

� We avoid the environmental impacts caused bywastes from intensive activities.


BMPs

� Best Management Practice (BMP), involves the mostefficient use of all inputs, including fertilizers,herbicides, seed varieties, and precision agriculturaltechniques (Goulding et al, 2008). Fertilizers havebeen central to this approach, which has resulted in atremendous increase in productivity over that last 40

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tremendous increase in productivity over that last 40years. For example, the efficient use of improvedfertilizers, combined with new varieties of wheat andthe successful use of crop protection chemicals, hasincreased grain yields from 3 tonnes per hectare toapproximately 10 to 11 tonnes per hectare today(Goulding et al, 2008).


� Moreover the current market economic incentives facingmany farmers are likely to encourage excess fertilizerapplication (Scott, 2005). It is generally recognized thatif eventually the adoption of market prices for mostagricultural goods without any subsidies became areality, in order to be competitive with the lower

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reality, in order to be competitive with the lowerproduction costs of developing countries in SouthAmerica, Asia, Eastern Europe and the Former SovietUnion, the pressure to intensify even the most UNITEDKINGDOM intensive production systems will as wellbecome reality despite the negative consequences on theenvironment (Goulding et al, 2008).


� However, the increased use of chemicals either fertilizersor pesticides in agriculture intensive systems isassociated with hidden costs due to environmentalpollution – in soil, water and atmosphere –,consequently has amplified the negative social effects onthe natural environment (eg. Shaink et al, 2002; Scott,

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the natural environment (eg. Shaink et al, 2002; Scott,2005 ). This argument is supported by an analysis of theexternalities from UNITED KINGDOM agriculture madeby Hartridge and Pearce (2001), finding that negativeexternalities amount to at least £1 billion, and positiveexternalities offset approximately half of these negativeeffects (negative/positive external).


The effect of fertilizers on the environment

� The relatively cheap price of N in relation to its yieldimprovement benefits, has been a central contributoryfactor in determining its overuse and consequently theenvironmental impacts.

� Agricultural emissions of nitrous oxide have fallen by13% over the 10 years up to 2005 and the trend iscontinuing (DEFRA, 2007).

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13% over the 10 years up to 2005 and the trend iscontinuing (DEFRA, 2007).

� However despite this reduction, the major directemissions of greenhouse gases (GHGs) are fromagriculture methane (CH4) caused by entericfermentation by ruminant livestock and manuremanagement, and nitrous oxide (N2O) from soils(Gibbons, 2005).


� Methane has a global warming potential (GWP) 21times greater than carbon dioxide while nitrous oxideGWP is considered 296 times that of the same mass ofcarbon dioxide (Houghton et al., 2001), consequentlyfairly small concentrations of these gas are sufficient to

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fairly small concentrations of these gas are sufficient toinduce drastic changes in the atmosphere.

� N2O contributes about 7% of the greenhouse gasemissions in terms of the GWP (Winiwarter, 2005).

� N2O is ranked third in importance behind carbon dioxide(CO2) and methane (CH4) (Winiwarter, 2005).


� N2O is a very stable compound in the atmosphere,with a mean lifetime of 120 years, so the emissionswill have an effect on the global concentrations in theatmosphere for many decades (Seinfeld and Pandis1998).

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1998).

� N2O is able to strongly absorb infrared light, thus italso exerts a considerable effect on the earth’sradiation absorption.

� Therefore, is obvious the magnitude of N fertilizationemissions has a dramatic effect on the environment.


� Approximately 1% of the anthropogenic N input intoagricultural systems is emitted as nitrous oxide, withagriculture as a whole contributing to 66% of totalUNITED KINGDOM nitrous oxide emissions in 2006,95% of it via direct emissions from agricultural soils(IPCC, 2006).

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(IPCC, 2006).

� In addition, fertilizer manufacturing is energy-intensive(Rounsevell and Reay, 2009).

� Carbon dioxide emissions from ammonia production –most of which is for fertilizer use – made up 0.3% (1.6million tonnes) of UNITED KINGDOM CO2 emissions in2006 (DEFRA, 2006).


� We cannot simply exclude or limit the application ofN to meaningless values. We should instead open anew channel of discussion in order to improve orformulate new policies in an enhanced cost-efficientway that decreases damaging effects on the

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way that decreases damaging effects on theenvironment and improves farms’ profits. This canonly be achieved if each of determinants of fertilizerapplication are well understood.


Livestock production systems and the main environmental challenges

� Based on the degree of integration with crops and itsrelation to land, the world's livestock sector has beenclassified into three broad livestock production systems(Sere and Steinfeld, 1996), i.e.

� grazing,

mixed farming and

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� mixed farming and

� industrial systems.

� For land-based production forms, i.e. grazing and mixedfarming systems, a sub-division is then required to allowfor differences caused by agro-ecological conditions andthe ways in which livestock affect the natural resourcebase.


Grazing systems

� Agro-ecological conditions strongly define the nature and scope of livestock-environment interactions in grazing systems. Therefore there is distinction between arid, semiarid and sub humid, humid and temperate grazing systems. In principle, grazing

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temperate grazing systems. In principle, grazing systems are closed systems, where the waste product (manure) is used within the system and does not present a burden on the environment.


� Resource degradation, especially of land andbiodiversity, is now developing in many of the world'sgrazing areas. For the most part this is occurring where,as a result of external pressures, traditionally well-managed common lands are becoming open access areas.In such open access situations, the interests of individualusers conflict with those of the community, causing what

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users conflict with those of the community, causing whateconomists call "market failures". In these "free for all"situations, degradation is most severe. On the otherhand, the grazing systems also offer potential forbiodiversity enhancement. Identifying institutions andincentives to correct the market failures and enhance thelivestock-environment synergies is thus one of thebiggest challenges in this system.


Farming system and environment 15

Mixed farming systems

� In mixed farming systems, crops and livestock production are integrated on the same farm. Globally, mixed farming systems produce the largest share of total meat (54%), and milk (90%).

� Resource use in mixed farming is often highly self-

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� Resource use in mixed farming is often highly self-reliant as nutrients and energy flow from crops to livestock and back. By definition, such a closed system offers positive incentives to compensate for environmental effects ("internalize the environmental costs"), making them less damaging or more beneficial to natural resource base.


Industrial systems

� These systems cover industrial types of production and small-scale urban or pert-urban production in developing countries.Both monogastric (pig and poultry) and ruminant productionsystems exist. They provide 37% of the total global meatproduction. These systems are open both in physical andeconomic terms. They depend on outside supplies of feed,energy and other inputs. These systems are strongly market

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energy and other inputs. These systems are strongly marketdriven, making them less resilient to market upheavals thanother systems. Because of their many interfaces with theoutside world, these systems, if not properly controlled, offermany opportunities to neglect ("externalize") theirenvironmental costs. The challenge is to identify theregulations and incentives which force the polluter tointernalize the environmental costs, at a minimum cost to theconsumer.


Global overlays

� In addition to the site-specific and production system relatedimpacts of livestock, such as land degradation in the arid zones,deforestation in the humid zones or livestock-wildlife interactions inthe savannas, there are a number of effects which transcend thespecificity of production systems. These are the global overlays,which include the environmental aspects of feed production, theemission of greenhouse gases, the erosion of wild and domesticgenetic resources, and the management of waste. As in the

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genetic resources, and the management of waste. As in theindustrial system, some of these impacts (for example, processingwaste) can be traced to one polluter (called "point sourcepollution"), and can therefore be controlled with appropriateregulation at the source. The other impacts cannot easily be tracedto one polluter ("non-source pollution"), and the challenge is thento find the incentives to encourage all producers to reduce theseemissions.


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Farming system and environment - Hill Agrichillagric.ac.in/edu/coa/agronomy/lect/agron-4711/Lecture 11 Farming... · agricultural practices will help in addressing socio-economic