Abstract
A field trial was conducted to establish an economic and environment-conservative rice culture. The yields of the direct-sowed paddy rice cultivated using Chinese milk vetch (Astragalus sinicus L.) as green manure and conventionally transplanted paddy rice cultivated using Chinese milk vetch or azolla (Azolla imbricata (Roxb.) Nakai) were compared with those cultivated using chemical fertilizers. The length of the period from plowing of Chinese milk vetch under the soil to the beginning of irrigation and puddling did not affect any yielding characters in either culture. The yield in the plot with Chinese milk vetch was about 30% lower than that in the plot with chemical fertilizers in the direct-sowed rice and about 10% lower in the conventionally transplanted rice. In this study, azolla did not increase rice yield, and further studies are needed to determine the effective method for application of azolla onto the rice field.
