It has been accepted by decision makers across the globe that sustainable development is the only way to promote rational utilization of resources and environmental protection without hampering economic growth. Different countries around the world are promoting sustainable development through sustainable agricultural practices which will help them in addressing socio-economic as well as environmental issues simultaneously.

Within the broad concept of sustainable agriculture "Integrated Farming Systems" hold special position as in this system nothing is wasted, the byproduct of one system becomes the input for other. Integrated farming is an integrated approach to farming as compared to existing monoculture approaches. It refers to agricultural systems that integrate livestock and crop production. Moreover, the system help poor small farmers, who have very small land holding for crop production and a few heads of livestock to diversify farm production, increase cash income, improve quality and quantity of food produced and exploitation of unutilized resources.

Components of integration in a farming system are parkland systems, trees on bunds, wind breaks, silvi-pasture system, agro-horticulture system, block plantations, economic shrubs, live fences, crops with green leaf manure species (mixed/intercrops), integrated animal based systems (fisheries, dairy, piggery, small ruminants, poultry, apiary).

This write up enumerates some examples of the integrated farming systems being practiced in Asian countries.

Case Study 1: Bio-diverse Multi-tier System

Rainfed agriculture is being adversely affected by four-fold problems of land degradation, degeneration of bio-diversity due to open grazing, climate change, and poverty driven over utilization of natural resources. All these problems together lead to increasing challenges for sustainability of dryland crop production.

These problems can be reversed, stopped, or at least reduced by adopting economy driven enterprises within the farming system and thus farmers can have higher and staggered income from the small land holding. A bio-diverse multi-tier system of farming, a kind of integrated cropping system, can thus be the answer. This system envisages a coupling of multipurpose trees, horticultural plants, health herbs, food/ oilseeds/ pulses, etc., with livestock rearing. The tangible benefit from this system could be the efficient nutrient and hydrological cycling, which can impart resilience by building soil quality with time. The staggered income is envisaged from the annual crops and livestock periodically from the horticultural plants of short duration species on long duration from woody species and from the bi/tri annual species and others in the system.

Over a period of time farming systems have evolved in semiarid tropics to suit the requirements for maintaining soil fertility and production related issues. The soil and water conservation measures coupled with vegetative cover on the agricultural lands can provide fodder and fuel, shade and shelter, wind break effect through vegetative barriers, sustain livestock etc., in order to provide livelihood security to the farmers.

Case Study 2: Crop- Livestock- Fish Farming

Asia has been the cradle of integrated crop-livestock-fish farming systems, which have evolved since the inception of human civilization particularly when human settlements started moving inland leaving the river banks. Though there are several successful practices of integrated fish farming in Asian countries including India, the system of farming using synergizing scientific integration of agriculture, aquaculture and livestock farming are not yet wide-spread in the region. Further, large-scale integration of carp culture with irrigation and sewage utilization are to be viewed seriously both for economic and ecological reasons (Sinha, 1979).

The wet land of paddy-field is congenial to many fish both for spawning and for pasture. Those breeding in paddy fields have adhesive eggs and are normally laid on green plants to facilitate more oxygen for developing embryo whereas shallow water spawners and the nest builders get favourable conditions of breeding in paddy fields. The flooded field has considerable quantities of putrifying plants giving rise to enormous amount of plankton and in fact serves as a richly laid table for fry and fingerlings. The fish while controlling the excessive growth of plankton, which compete with the paddy, also control zootecton, insects, molluscs, the submerged and floating weeds harbouring the above and adversely affecting paddy. Fish fertilize through its fecal matter and also overturns the submerged soil normally under reduced stage thus making available more nutrient and oxygen to the root of paddy, acting like a biological plough (Sinha, 1985).

Evolved on the principles of productive recycling of farm wastes, fish- livestock farming systems are recognized as highly assured technologies for fish cultivation. In these technologies, predetermined quantum of livestock waste obtained by rearing the livestock in the pond area is applied in pond to raise the fish crop without any other additional supply of nutrients. Similarly, with the integrated poultry - fish farming system, the fish crop is integrated using only poultry droppings or dip litter by rearing the poultry either directly over the pond or on the pond embankment.

Case Study 3: Dyke-Pond Systems

In many parts of Asia, the productive use of land and water resources has been integrated by transforming wetlands into ponds separated by cultivable ridges. Overall integrated farming systems that include semi-intensive aquaculture are less risky for the resource-poor farmer than intensive fish farms, because of their efficiency derived from synergism, their diversity of produce, and their environmental soundness. In many traditional systems aquaculture goes beyond fish production and cash income as pond water and pond biota perform many ecological, social, and cultural services on an integrated farm. Thus aquaculture and water management act as an engine driving the sustainability of the entire farming system (Lightfoot 1990).

An example of integrated agriculture–aquaculture system is the dyke-pond system, which has existed for centuries in South China. The history of the dyke-pond system may be traced back to the middle of the ninth century in the Pearl River delta region of China.

The dyke - pond system serves two major functions: (a) achievement of a general ecosystem balance through the harmonization of well-coordinated activities and functions embedded in the ecosystem, and (b) transformation and regeneration of organic substances based on a multi-layer trophic eco-system structure, which helps contribute successfully to sustainable economic development. The system contains two interrelated systems of dyke and pond; the dyke is the land ecosystem for the growth of crop whereas the pond is the water ecosystem, consisting of fish and aquatic plants. The dyke-pond system can be of various kinds depending on the crops planted on the dyke such as mulberry dyke-fishpond, sugar cane dyke-fishpond, banana dyke-fishpond, and so on. The input and output of material and energy in the dyke-pond system are basically balanced. (Ruddle & Chung, 1988 and Korn, 1996).

Experience showed that the economic return from the integrated mulberry dyke-fish pond system were greater than those obtained from cultivating fruit trees or rice on the dyke. It was found that such integrated management is beneficial to mulberry and fish, as well as for development of sericulture. Moreover, pond mud enriched with silkworm excrement and other wastes can be used to fertilize the pond and feed the fish. Mulberry leaves are fed to the silkworms, whose excreta are used as fish food, and the fertile pond mud, consisting of fish excreta, organic matter, and chemical elements, is brought up from the bottom and used as manure for the mulberry trees.

In this system, the mulberry tree represents the first trophic level. Photosynthesis takes place in its leaves, which are fed to the silkworms for yarn production (the primary consumers) whose excreta and chrysalises are in turn fed to fish (the secondary consumers). The aquatic organisms in the pond are the reduction agents that decompose fish excreta and algae, break down the organic matter in the pond, and produce nitrogen, phosphorus, and potassium. The pond supplies the dyke with the fertile mud, which after decomposition is used as a primary source of fertilizer for the mulberry trees.

Moreover, the leaf fodder of mulberry is reported to be rich in crude protein, ether extract, calcium, ascorbic acid, potassium, iron and thus can be profitably utilized as a supplement to poor quality roughages (Singh and Harinder). Mulberry leaves can also be used in poultry ration. Incorporation of shade dried mulberry leaves in layer’s mash to the extent of 6 per cent showed an increase in egg production with desirable yolk colour without any adverse effect on body weight and egg quality (Narayana & Setty, 1977). Mulberry leaves, owing to their high carotene content, can form a valuable source of vitamin A for the health of poultry birds and increased egg production.

In India such integrated systems have not been systematically evolved so far, however in many places, the pond mud is used for terrestrial crop and pond embankment for papaya, coconut, banana plantation and at times for growing vegetables.

Way forward

Further research and field demonstrations are required to develop suitable models for efficient integrated farming systems relevant to the specific region. For technology transfer and making farmers aware about the technology capacity building trainings and appropriate communication strategy is required. q

References:

• B. Singh .and Harinder P. S. Makkar. The Potential of Mulberry Tree Foliage as an Animal Feed Supplement in India (available at http://www.fao.org/docrep/005/x9895e/x9895e0d.htm as on 3 May 2010).

• Bio-Diverse Farming System Models for Dryland Agriculture, Central Research Institute for Dryland Agriculture Hyderabad (available at http://www.crida.ernet.in/AICRPDA/Bio-Diverse.pdf as on 5 May 2010).

• H. L. Sun, S. K. Cheng, and Q. W. Min. Regional Sustainable Development Review: China. Encyclopedia of Life Support Systems (EOLSS).

• Korn, M. 1996. The dyke-pond concept: sustainable agriculture and nutrient recycling in China. Ambio 25(1): 6-13.

• Mae-Wan Ho. Sustainable Agriculture. Green Energies and the Circular Economy. International Workshop on Sustainable Food and Agriculture, Beijing 13-15 March 2010. (available at http://www.i-sis.org.uk/greeningChinaSustain ableAgriculture.php as on 4 May, 2010).

• Miguel A. Altieri. Agro ecology: Environmentally Sound and Socially Just Alternatives to the Industrial Farming Model. University of California, Berkeley. (available at http://www.agroeco.org/doc/Altieri-Alternatives%20to%20industrial 20model-part%201.pdf as on 3 May 2010).

• Mulberry dyke fish pond model, China: a sustainable traditional method of land-water ecosystem. Good Practices Inventory. Asia-Pacific Environmental Innovation Strategies (APEIS). 2004 (available at http://enviroscope.iges.or.jp/contents/APEIS/RISPO/inventory/db/pdf/0152.pdf as on 5 May 2010)

• Narayana, H. And Setty, S.V.S., 1977. Studies on the incorporation of mulberry (Morus indica) leaves in layers mash on health, production and egg quality. Indian Journal of Animal Science 47, 212-215.

• Ruddle K. and Chung K.F. 1988. Integrated agriculture-aquaculture in South China: the dyke-pond system of the Zhujiang Delta. Cambridge University Press, Cambridge.

• V. R. P. Sinha (1979). New Trends in Fish Farm Management. In: T.V.R.Pillay & Wm. A. Dill (Eds.), Advances in Aquaculture, Fishing News Books Ltd., England, 123–126.

• V. R. P. Sinha. Integrated Carp Farming in Asian Country. Network of Aquaculture centres in Asia Bangkok, Thailand. September 1985 (available at http://www.fao.org/docrep/field/003/ac236e/ac236e00.htm as on 5 May 2010).

• Y. S. Peng and G. Z. Chen. A Brief Introduction to the Pearl River Estuary Wetland, Southern China. November, 2007. Thailand. (available at http://www.unepscs.org/Wetlands_Training/Wetland%20Case%20Studies%2 0and%20Country%20Reports/30-Wetland-Management-Pearl-River-China.pdf as on 3 May 2010).