ECO-TOURISM: SHUNDE ECOLOGICAL PARK

Dike-pond farming

Characteristics of Dike-pond System

Dike-pond system integrates agriculture and aquaculture into one ecosystem of cultivation which highly suited to flood-prone low-lying areas (Lo, 1996). In these areas, ponds are excavated, and the dug-out soils or muds used to raise the level of the low-lying ground surrounding the ponds, thus forming the dikes. In this way, the danger of flooding is alleviated, while drought can also be regulated. Inside the pond there are draining ditches which allow pond water to be drained if required. The juxtaposition of ponds (water) and dikes (land) makes it possible for the two separate components to interact and function as one ecosystem (Zhong et al, 1993).

Fish are raised in the ponds and crops are grown on the dikes. Feces from the fish, which accumulate at the bottom of the pond, are used as organic fertilizer for the crops growing on the dikes, and crop residues, such as stalks, are used to feed the fish. In this way wastes generated in each system are disposed of efficiently by generating nutrients to sustain production in another component of the system. The ratio of land to water in the system is an important consideration because it affects the energy flows (nutrients) between the two components. In PRD, the typical ratio adopted is 50% dike to 50% pond, or 40% dike to 60% pond, measured in terms of areas. These ratios have come about through long periods of trial and error by the farmers, a typical approach in the development of agricultural technology in China. The usual size of such an integrated dike-pond system is about 0.41 ha (or about 1 acre).

Following the Economic Reforms of 1978, and a greater variety of crops has been grown on the dikes, and new species of fish introduced to the ponds (Lo, 1990). Four basic types of dike-pond systems have emerged:

1. Mulberry and sugar cane dikes with fish ponds;
2. Mulberry and sugar cane dikes with fish ponds in combination with horticulture and paddy rice cultivation;
3. Mulberry and sugar cane dikes with fish ponds in combination with elephant grass, vegetables, and paddy rice cultivation;
4. Predominantly paddy rice and sugar cane cultivation, horticulture, and fish ponds, with dikes not being used at all.

These variations in crop combination reflected differences in the physical environment of the delta and the accessibility of the sites from the market(s).