The Research On The Ecological Coupling Mode Of Planting And Feeding In The Paddy Field In Qujing City

The technology of raising fish in the rice field has become an important measure to increase the output and quality of paddy rice, and the ecologically economic efficiency. In recent years, the mode of raising duck in the rice field, which doubles the harvest of rice and duck, has been confirmed successful by the experimental result; and the compound pattern of raising fish and duck in the rice field achieved success through four years' experiment (1990 - 1994) in Chongqing. It has been spread widely. However, while raising duck outside in the rice paddy, the research of raising the eel and green duckweed on the rice field has not been reported in the media.Based on the experimental study of the comparison between the pattern of four kind of ecology plants and raising (raising duck in the rice paddy, raising eel in the rice paddy, duck and eel cultivation in the rice paddy, and raising duckweed on the rice paddy) and the local conventional rice planting (comparison), it indicates that:1. In the soil ecology aspect, On the mode of rice-duck-eel: Soil bulk density decreased 0.024g/cm~3. The quantity of the soil aggregate (> 0.25mm) increases 3.37%. The quantity of micro-aggregate (< 0.001mm) decreased 1.89%. The dispersion coefficient decreased 6.43%. The structure coefficient increases 6.43%. The organic matter increases 0.91 g/kg. Total-N increases 0.6 g/kg. Available-N increases 25.34 mg/kg. Available-P increases 4.41 mg/kg. Available-K increases 45.99 mg/kg; On the mode of rice-duck-eel-duckweed: Soil bulk density decreased 0.053g/cm~3. The quantity of the soil aggregate (> 0.25mm) increases 5.07%. The quantity of micro-aggregate (< 0.001mm) decreased 2.26%. The dispersion coefficient decreased 6.61%. The structure coefficient increases 8.86%. The organic matter increases 1.01g/kg. Total-N increases 1.23 g/kg. Available-N increases 50.21mg/kg. Available-P increases 6.23mg/kg. Available-K increases 53.5mg/kg.. The physics and chemistry character of the soil is improved greatly.2. In the rice paddy ecology aspect, On the mode of rice-duck as respectively been reduced by 97% and 86%; insect pest has equally been reduced by 94% and 98%; he mode of rice-duck-eel disease rate has been reduced by 97%; On duck-fish-duckweed cultivation in rice field; disease rate has equally fallen to the lowest.3. In the economic efficiency aspect, duck-eel cultivation and duck-fish-duckweed cultivation in the rice field, good rice rate has respectively been increased by 7.3% and 9.4%; because it is the ecologyrice, the rice unit price enhances 0.20 Yuan/kg; its net income of each 667m2 increases respectively 235.75 Yuan and 552.96 Yuan. From the comparison between investment and produces, duck-fish-duckweed cultivation in the rice field is the best. Its order of rank is: the rice field duck-fish-duckweed cultivation (2.00) > rice (1.97) > rice-duck (1.88) > eel cultivation (1.82) > duck-eel cultivation (1.74).4. In the social efficiency aspect, it is advantageous to the industrial structure adjustment. It enriches the agricultural product supply in the market and enhances farmer's ability to resist the market risk.This experiment shows that the mode of rice-duck-eel or the mode of rice-duck-eel-duckweed in the rice field is an extremely remarkable rice paddy comprehensive utilization pattern, which is ecological, economical and full of social efficiency.