Abstract
To suggest the weed management technique for environment friendly rice cultivation, we investigated occurrence patterns of weeds, the actual condition of weed management, and rice yield at the environment friendly agricultural complex located in Honam and Chungnam regions. The practical performance of weed management was relatively satisfactory in decreasing order of agricultural technique with golden-apple-snail (GAS) > agricultural technique with duck (Duck) > agricultural technique with rice bran (RB) > agricultural technique with soft-shelled turtle (ST). In the rice fields employed by agricultural technique with GAS, the dominant weeds were Echinochloa crus-galli, Ludwigia prostrata, Monochoria vaginalis, Sagittaria trifolia, and Aneilema keisak. However, E. crus-galli, M. vaginalis, L. prostrata, Aeschynomene indica and Bidens frondosa were found as dominant weeds at the fields using the Duck and E. crus-galli, M. vaginalis, L. prostrata, Polyganum hydropiper and Eleocharis kuroguwai at the fields using RB. In comparison of rice yield ($5.2\;MT\;ha^{-1}$) obtained from the conventional cultivation using herbicides, about 93% was reached by Duck, about 91% by GAS, about 92% by RB, and about 78% by ST. When rice qualities obtained from environment friendly rice cultivation were compared with those from the conventional cultivation, the producing rates of perfect kernel, immature kernel, immature opaque kernel, cracked rice, and damaged kernel were lower in the former cultivation, whereas contents of protein, amylose, and fatty acid were similar in the two cultivation methods. The problems found in the environment friendly agriculture were poor plowing and harrowing, carless irrigation management, and geological poor condition as cultivation area with cold water. These have caused severe infestation of weeds, frequent incident of disease and insect pest, and rice lodging. This resulted in reduction of rice yield as high as about 32 to 79% as compared with the conventional cultivation using herbicides.
친환경 벼 재배를 위한 효과적인 잡초관리 방법을 제시하고자 호남 및 충남지역에 위치한 친환경 농업단지에서 있는 농가포장을 대상으로 잡초 발생 양상, 관리 실태 및 쌀 수량 등을 조사하였다. 친환경 농업지역의 잡초방제 관리실태는 왕우렁이농법> 오리농법> 쌀겨농법> 자라농법 순으로 감소하였다. 친환경 농법별우점 초종은 왕우렁이농법에서 피, 여뀌바늘, 물달개비, 벗풀, 사마귀풀이, 오리농법에서 피, 물달개비, 여뀌바늘, 자귀풀, 미국가막사리가, 쌀겨농법에서 피, 물달개비, 여뀌바늘, 여뀌, 올방개 등이었다. 친환경 농법별 쌀 수량은 제초제 처리 농가($5.2\;MT\;ha^{-1}$)와 비교하여 오리농법 93%, 왕우렁이농법 91%, 쌀겨농법 92%, 자라농법 78%이었다. 쌀 품위 중 완전립율, 사미, 착색립, 동할미, 피해립 등은 관행재배보다 낮았으며, 단백질, 아밀로스, 지방산은 관행재배와 유사하였다. 친환경 농업지구 관리 문제점은 논토양 정지 불균일, 배수관리 소홀, 냉수재배지 등 지형적 불리한 조건으로 잡초가 다발하거나 병해충 발생 및 도복 등으로 인하여 수량이 관행재배 대비 약 32~79%가 감소되었다. 따라서 논에서 친환경 농법으로 재배를 할 경우 지형적으로 불리한 지역에서 친환경 농법은 배제되어야 하며 균평작업을 통하여 토양 표면을 일정하게 유지시키는 것이 매우 중요한 것으로 확인 되었다.
