Integration of Aquaculture and Agriculture:
A Route to Sustainable Farming Systems

The ways farmers use natural resources can no longer meet the demand for food and income,let alone the need for environmental conservation. Certainly, present farming systems will not meet projected food needs for the 21st century. We need more research that combines ecology and production knowledge and integrates many diverse enterprises at the farm level.

New ways of farming that regenerate environments and generate income must be designed, tested and implemented by large numbers of farmers. Important components of such systems will be biological diversification and nutrient recycling. Where there is sufficient water the integration of aquaculture and forestry into farms provides an appropriate starting point for the design of regenerative farming systems.

Many of today's farming methods degrade the environment. Poverty forces farmers to adopt non-sustainable systems. Slash-and-burn cropping which was once sustainable now contributes to an estimated 10 million hectares of deforestation yearly worldwide. Some 142 million hectares of rainfed crop land in Southern and Sudano-Sahelian Africa have become "desertified," as have an estimated 150 million ha in South Asia. Salinization irrigated land affects 5 million ha in South Asia.

Farmers understand the impact of their practices on the environment. But their farming practices are an indication of their lack of alternatives to earn a living. This situation poses a challenge to find affordable technologies to improve soil and water resources and to enable farmers to use these resources more efficiently.

The need for new sustainable farming systems has been recognized for decades but there is a general lack of vision as to how they might be developed. One major reason for this is the "tunnel vision" of researchers locked into their narrow disciplines and sectoral issues.

Farming-Systems Research and Extension

Farming-systems thinking is rare. However, recent developments in Farming Systems Research and Extension (FSRE), particularly in agroecosystems analysis, allow scientists to see opportunities for intensifying resource use and regenerating environments through the integration of agriculture and aquaculture. Aquaculture provides a way to use agricultural waste to regenerate marginal lands. Fish convert plant and animal waste into high-quality protein and enrich pond mud for use on crop land.

The value of this kind of analysis is exemplified in the International Center for Living Aquatic Resource Management (ICLARM) collaborative research in Malawi and India.

Malawi

Farmers in Zomba district, Malawi, identified six land types from mountain to river plain. An agroecosystem analyst arranged the land types in sequence to form a "composite" transect listing all enterprises, soils and water characteristics. Floodplain lands are divided by types and according to use, and further subdivided according to whether they are cultivated or not. Crop and livestock enterprises vary accordingly. Fishponds are constructed on wetlands and homestead land where a water source permits.

Zomba's agroecosystem transect suggests many points for joining land and pond "crops." Pond mud would revitalize vegetable plots. Pond water could irrigate vegetables and water animals. Animal manure, along with crop residues, weeds, tree leaves, and rotten fruit and vegetables could fertilize ponds as well as the soil. Other crop by-products like maize and rice brans could be fed to fish. Occasionally one finds a farmer who is exploring these connections. Some have upgraded diminished wetland into orchards, fishponds, fodder and vegetable plots. In essence they are intensifying the use of natural resources in a sustainable manner through species diversification and nutrient recycling. Productivity increases, farmers' incomes rise, soils are improved and the water is kept clean.

India

Land-type transects described by farmers from Dhobigama, India, suggest several ways to link farm and pond. For example, uplands are not only where people live and livestock shelter but also where fruit trees and fish are raised. Cereals, pulses and vegetables are grown on sandy loams of the cultivated uplands. With few exceptions, terraces of bunded rice cover the remaining land types. Where the water table is low enough, these silty loams and clay loams support many crops after rice, and livestock graze them during the off-season. In the flood-prone land, migratory fish are often caught.

Similar to the Malawian farmers, a Dhobigama farmer, who was dissatisfied with poor productivity, upgraded his own flood-prone land. He dug out the flooded area and made several mounds nearly 2 m high and 4 m wide and planted fruit and sesso trees on them. While the trees were still small, undercropped vegetables provided an immediate income. In the ditches, which now had more assured water, the farmer was interested in raising fish.

Such seemingly great potential for intensifying the use of marginal lands in this manner raises the question: Why are FSRE and agroecosystem tools so underutilized?

Perhaps the most important reason is the institutional structure in which agricultural research and development is conducted. FSRE requires social and biological scientists to work alongside each other, yet these scientists are separated by the disciplinary structure of universities. Moreover, interdisciplinary teams require all members to have a working knowledge of the other disciplines but education programs rarely offer appropriate courses. Agroecosystem analysis and the new farming systems it inspires require integration of crops, livestock, fish and forestry but these commodities are separated at national and international levels. Institutional barriers inhibit the growth of expertise, the flow of funds and the use of FSRE and agroecosystem tools.

Even the leading scientists concerned with a holistic treatment of farming systems often omit whole enterprises from their analyses. Indeed, most studies reflect the bias of the lead discipline. Thus, fish biologists working on integrated agriculture/aqua-culture systems concern themselves mainly with the fish, the pond and the use of agricultural residues to feed the fish. We can conclude that a contributing factor to the lack of new farming systems development is the attitude of scientists.

To make degraded land productive and farmers' incomes larger, new farming systems must promote integration of crops, vegetables, trees, livestock and fish, and exploit all opportunities for nutrient recycling and other synergisms between enterprises. One component's by-products must be another's inputs. Scientific procedures for quantifying, analyzing and experimenting with farming systems of this breadth and complexity are sorely lacking.

Even if new farming systems of such complexity can be synthesized it is the farmers who must implement them. Model integrated farms developed on research stations are rarely adopted. Few FSRE initiatives get sufficiently large number of adopters to show a real impact. Operational procedures for mass farmer participation in an evolutionary research process with alternative goals and pathways are badly needed. ICLARM would appreciate readers' ideas on the needed procedures identified in this article.

Condensed from an article by Clive Lightfoot, Integration of Aquaculture and Agriculture: A Route to Sustainable Farming Systems. 1990, Naga, The ICLARM Quarterly, January.

Contact:

Clive Lightfoot
ICLARM
MC P.O. Box 1501
Makati, Metro Manila, Philippines
Fax: (63-1)816-3183
Telex: 64794 ICLARM PN (ETPI)