Scope of Sustainability
Sustainability in agriculture is studied and expressed by different research workers in different ways, restricting their perception of sustainability in one way or other.
Bhol (1995) from North Carolina reported sustainability of soil use. He recognised the limits of sustained yield as a function of the capacity of soils to contain/release nutrients. he also declared that no soil can sustain constant depletion of critical elements and their is need to compansate such depletion to make soil sustainable.
Canadian workers like Hilborn and Landwig (1993) restricted their scope of sustainability to sustained fish production based on theory of reproductive surplus. they opined that all natural population are capable of net population growth under favourable conditions and sustainability will mean to harvest the surplus population.
Hoffmen and Coroll (1995) stressed on improving the biological basis for long-term agriculture sustainability by emphasising on the management of renewable resources (improvement of soil organic matter enhancing microbial activities, selecting varieties suitable for vesicular arbuscular mycorrhizae species exploitation. Finding better matches between crops and local environment.
Solow (1993) understood sustainability as an obligation to conduct selves so that we leave to the future the option or the capacity to be as well as we are. He added soil and moral angle of making future generation to be equally eligible to generate the benefits fo population from nature as we are.
Goodland (1995) from World Bank reported that sustainable development should integrate social environment and economic sustainability. He also defined that environment sustainability world includes atmosphere, water, soil whose services are referred to as environmental services.
Although the meaning of sustainability can be applied to many aspects of agriculture, more comprehensive and meaningful approach, to widen the scope of sustainability of all the component of the ecosystem for a hormones co-existence sustainability in agriculture refers to the sustainability of crop yields, of net returns, of soil fertility and of eco-system.
Individually, these four types of sustainability means:
Sustainability of net returns: often referred as economic sustainability. It signifies or forms over a long period of time.
- Crop Yield Sustainability: Maintenance of rate of increase of crop yield over a long period of time.
- Soil Fertility Sustainability:- Maintaining the fertility of the soil (in terms of its inherent capacity to produce, store and release the plant nutrients) even after a long period of cultivation.
- Sustainability of eco-system: It means that futures of agro ecosystem (ex: integration between soil fertility and soil microbes) remain unaffected by cultivations of crops for a long period of time.
The sustainability is necessary to be achieved in all four sectors viz. net return, crop yield, soil fertility and ecosystem.
None of them is independent, as a very close relation exists among them.
Some pragmatic scientists and planners go a step ahead to find that more maintenance of crop yields does not signify the growing needs and it is necessary to ensure increasing trend in crop yields. while such pragmatism is certainly desirable, the stark truth of stagnant production is the first to be addressed before any pragmatic strategy. More are, a pragmatic policy of increasing the crop yields has no meaning if the fertility of the soil and condition of eco-system are not conducive to achieve the same. the combination of the pragmatic strategies to increase the crop yields and strategies of sustaining the fertility and condition of the ecosystem are necessary to achieve the overall system of sustainability.
Economic Sustainability: Achieving economic sustainability is crucial because it can motivate the farmers to continue the profession of agriculture, improve has standard of living and ensure that adequate capital is invested in agriculture. But, achieving the economic sustainability is controlled by factors beyond the farm and farmer. for example, he has no control over market forces (demand and supply) as well as price fixed to his product. Hence, inestimable crop yield may not lead necessarily to economic sustainability. In India, farmers are compelled to continue in agriculture because
No alternative profession/employment is available
Necessity to continue agriculture as family profession
Cost of living in his own village is far less than elsewhere
Most farmers may not retain economic sustainability. But they have to continue, with continued low standard of rural living and unachieved economic sustainability, the return from agriculture are more likely to be used for consumable expenditure. (Sometimes even to maintain minimum requirement of food education, shelter and clothing) them as the productive investment to improve the soil fertility and ecosystem. this result in the vicious cycle of unsustained agriculture, as less and lesser investment, leads to weakened soil fertility and disintegrated ecosystem, which leads to ultimately to unsustained crop yields.
One of these resource economic sustainability is of persisted importance with wider implications. for a for more, higher income may be more essential than higher cost yields or sustained fertility/ecosystem.
Economic sustainability is also dependent on the cost of cultivation besides the income generated. Hence, factors to reduce the expenditure are as important as factors to increase the yield. A farmer has to reduce the cost of cultivation in all possible ways to achieve the economic sustainability.
Sustainable crop yields
Although IM remunerative prices and increasing the cost of cultivation can convert a sustained crop yield record into unsustained net return, when the crop yield itself is unsustained, the farmer suffers double losses.
a) due to unsustained net returns
b) negative impact of unsustained yield or gross returns.
Sometimes gross returns are not even able to cover the cost of cultivation resulting into zero or Negative return. Hence, maintaining the crop yield is absolutely essential.
The sustainability of crop yields, although desirable is certainly a complex issue involving complicated negative and positive correlation of several factors. any of these factors may nullify the beneficial effects of other factors. Therefore, the productivity of the crop toggles between the positive and negative side of seeds due to productions factors to settle down at a particular level.
Sustainable soil fertility
Soil fertility is often referred to its capacity to store and supply the plant nutrients to the crop roots. This involves, in its background, release and fixation process of nutrients. all four processes are carried on as an integral system in the soil due to ph yo cel, chemical and biological characteristics. Hence, soil fertility is a compound function of all these characteristics of the soil.
1. The physical characters such as texture, structure, bulk density, water holding capacity, infiltration rate, hydraulic conductivity, pH, chemical characters such as cation exchange capacity, salinity, alkalinity, phosphorus and potassium as well as micronutrients such as zinc, iron, sulphur, calcium, boron and manganese, biological characteristics like population of bacteria, fungi, actinomycetes, arthropods, annelids, vertebrates as well as their species composition are important consideration in soil fertility.
In this background, maintaining soil fertility in long run involves strengthening the capacity of soil to carry out the essential processes of release fixation, storage and supply of nutrients. The practice of applying fertilisers deals with supply process alone and cannot strengthen other processes like the release, storage and fixation because fertilisers are in inorganic form while all these functions are carried out as organic function.
Even the supplying process of nutrients by applying fertilisers is not in time with crop requirement. the available pool of particular nutrients, in fact, inundates the soil medium much beyond the combined capacity of roots and soil to handle when the fertiliser is applied. all unused nutrients are naturally lost in various paths. such as volatilization and leaching. this leads to nutrients scarcity after a lapse of 10-15 days.
On the contrary, the nutrients demands of the crop roots are gradually reaching the peak during the critical stages such as tillering flowering and fruit development. these two contrasting scenarios never match. Hence, applying fertilisers alone has resulted in unsustained fertility of our soils.
In sustaining the soil fertility, the necessary steps should be taken to improve the physical condition of the soil, to strengthen the chemical mechanisms and to support the biological activities of the soil. Any material used to do these and any method adopted to achieve these will find a place in sustainable fertility.
The results of unsustained fertility, which is the product of negligence of maintaining desirable physical chemical and biological condition of the soil are clearly manifested in the yield trends of the crop over years. A quick survey of the crops and their varieties as correlated to their productivity in the last 15 to 20 years clearly indicates that contribution of soil fertility to the productivity is merger and some big nations are nil. The increase in the productivity recorded in last 15 years to 20 years is mostly due to improved varieties/hybrid of the crops.
The productivity of the crops with no drastic improvement programme ( eg. pulses, oilseeds) has most increased varied significantly. But, the increased productivity, due to varietal improvement is not permanent in nature. This is evidenced by many crops (eg. DCH-32 hybrid cotton, CSH-105 sorghum). Unless the fertility of the soil is built to support the crop yield in long run, the termed productivity cannot be obtained. Hence, the sustained soil fertility is indispensable for the future of agricultural production.
Justification to achieve the sustained fertility lies in complete neglect of the biological and physical domains of the soil by present day agriculture. The use of fertilisers has rendered the soil into a non-living medium of flooding the nutrient ions and has neither strengthened the biological activities nor improved the physical properties of the soil. if sustained soil fertility is to be achieved, the holistic strategies of improving all the physical, chemical and biological characters of the soil are necessary to be developed so that all four processes viz, storage supply, release and fixation are strengthened
An agroecosystem is an integral unit of soil water crop living beings existing in harmony with a well-balanced equilibrium of food chains and their related energy balances
An Ecosystem is a large domain embodying fertility domain and crop domain. Hence, the sustainability in ecosystem leads to sustainability of both fertility and crop yield in broader sense over a long period of time. It is absolutely essential to sustain an ecosystem not only for an objective of achieving the sustainable crop yields and fertility but also because of an ecosystem leads to more stability in nature by the establishment of the more integrated relation between components of an eco system. Hazards due to use of synthetic and chemical material nature can only be minimised by the sustainable eco system.
In achieving the sustainability of eco-system below given are considered
Well, being and population harmony of all the biological components like microorganism, arthropods, annelids and vertebrates.
Reduced hazards effects of various chemicals involved in a system in components of ecosystem viz. bio hydro and physical components.
Identifying and strengthening the intricate relationship between natural enemies/predators in an agro ecosystem/to control the pests and diseases of crops
Linkage of Organic farming with sustainability
Organic farming is an impressive than a choice. It is much near to nature and natural processes than chemical Increase. It can achieve greater sustainability than chemical farming.
Sustainability of present level of crop productivity is at stake in may crop with continues use of fertilisers. Sustainable increase in productivity has not been achieved in a few other crops. Both these yield sustainabilities are essentially dependent upon sustainable fertility and ecosystem. The role of organic farming is not restricted to more supply of nutrients (as in case of fertilizers). Its primary role extends to improve soil quality, measured in terms of physical and biological characters.
The source of organic farming are able to naturally fit themselves into an agro ecosystem than chemicals and therefore, are able to mould the soil system to long-term sustainability. The biological basis of sustainable crop yield increases in sustainable fertility and sustainable ecosystem. The increase in productivity or maintenance of productivity of crops can be achieved of fertility and ecosystem are able to be maintained at their best natural forms. Such possibility exists only with the practice of organic farming rather than chemical farming.
Achieving sustainability of ecosystem and soil fertility is a slow process, as the lost equilibria are to be reestablished in organic carbon stat should be gradually improved; soil macroaggregates are to be increased and retained, the food chain of ecosystem are to be reformed. The improvement of crop yields depends upon such changes in eco-system and soil fertility. A sudden improvement in crop yield cannot be expected (like what was recorded by use of fertilisers) as the organic farming methods can improve the ecosystem and soil fertility by the slow process of rebuilding.
The practice of organic farming to achieve sustainability is a holistic approach aimed to improve the crop yields through the sustainability of ecosystem and fertility. Undisputedly, such advocacy is far variance from any short-term recommendation to achieve quick solution such as
Recommending the use of the synthetic pesticide against the pest.
Recommending a fertiliser to correct the nutrient deficiency.
Such recommendation was made in chemical farming only to achieve short-term interest ignoring the natural equilibria and natural components. Repeated use of short-term measures of this nature is the sense of sustainability of fertility and ecosystem. To achieve sustainability, organic methods of nutrient supply and pest control are necessary to be followed notwithstanding that such methods may take more time to achieve results in terms of increased crop yields.
In understanding the linkage between sustainability and organic farming the essentiality of supporting and augmenting natural process in an agroecosystem needs to be realised organic-farming practices strongly make use of natural processes such as natural enemies, predators, food chain etc. for pest control as well as decomposition, N-fixation, structural improvement of soil etc. for supply of nutrients. All these processes are in tune with the holistic improvement of soil fertility and ecosystem which are essential components of sustainability.
The protagonists of chemical farming lose the sight of such holistic approach and end up restricting the meaning of sustainability to crop yield alone. Under such considerations, the organic farming may or may not lead to sustainable in usage in crop yield depending upon the level of soil fertility and eco-balance already achieved under extreme conditions of depleted fertility and impaired eco balance organic farming may reduce crop yield in initial years. Under well-managed conditions, crop yield may be maintained or improved in the concise of time.
The basis of improved crop yield on long-term basis lies in the sustained soil fertility and ecosystem deserves more concern than short-term improvement of crop yields. Organic farming alone has the potentiality to achieve such sustainability, as well as organic farming practices, are in tune with natural processes of an agro ecosystem.
Thus, the linkage between organic farming and sustainability is not strong and complete. It is natural and obvious. Even achieving sustainability (of not only net returns and crop yields) of the whole ecosystem and soil fertility is an option but a national necessity and social requirement. Without sustainability, perhaps the whole production system will collapse gradually.
The time frame to achieve sustainability through organic farming more be varying according to the level of soil fertility and eco-balance available in question. Sustainability of yield may take 4-7 years while sustaining of fertility.