The Characterization of Cover Plant Communities under a Paddy Environment in the Inland Valleys of Ghana

Abstract

Paddy rice requires relatively large amounts of water. Its field irrigation provides a stable supply of water in rice fields and contributes in increasing the rice yield. In the inland valleys of Ghana, a reinforcement technology for irrigation facilities in paddy fields is being developed by planting native plant species on the ground surface of irrigation and drainage canals and levees. In order to sustain long term reinforcement, it is important to maintain and manage the vegetation appropriately. Concerning the characterization of native plant communities, the bare canal crowns were invaded in succeeding order by Cynodon dactylon, Chrysopogon aciculatus, and Stenotaphrum secundatum. Concerning the community structures, Stenotaphrum secundatum showed the highest above-ground plant fresh weight and Chrysopogon aciculatus the highest root fresh weight. Moreover, the root systems of the three plants were concentrated within the 10 cm soil surface layer. In an established community which was left unmanaged for one year, there was an invasion of weeds with the Cynodon dactylon communities being fewest and their total fresh weight the lowest as compared with the other two communities. These results demonstrate the validity of the maintenance and management schedule of plant communities such as the timing of planting, replanting, manual weeding, cutlass slashing and so on, and the clarifying of the characteristics of the established plant communities in terms of structure and stability.