Weeds are the major hindrance in the adoption of conservation agriculture in a rice wheat cropping system. There exists a conflict in the agronomic and soil requirements between a conventional rice production system and the following wheat crop. Puddling in the conventional rice productions system helps in controlling weeds in rice and following crops, but disturbs the soil structure resulting in poor stand establishment of the following wheat crop. This study was conducted to monitor the soil properties, weed dynamics and stand establishment of wheat grown by conventional and conservation tillage options after different rice production systems. Maximum soil bulk density and root penetration resistance was observed after a conventional flooded rice system with the lowest values in aerobic rice culture. Wheat stand establishment was impeded following flooded rice system; however this was quite better after the aerobic rice. However, after flooded rice, wheat stand establishment was improved with deep tillage. Hydropriming was better in improving the stand establishment than osmopriming. Weed biomass was highest after the aerobic rice; however it was a minimum after the flooded rice. Amongst the tillage systems in wheat, maximum weed flora was observed in zero tillage; however that was a minimum in bed sowing. Conservation agriculture may help in improving the stand establishment in rice wheat cropping system by improving soil physical properties, but weeds are still a major threat to adopting this form of agriculture.

고랭지 경사밭의 토양보전을 위해서 고랭지 배추재배지에 애기기린초, 범의귀, 지면패랭이, 긴병꽃풀 등 4종의 지피성 동반작물의 도입가능성을 경사도 5, 15 및 30%의 라이시미터에서 평가하였다. 애기기린초를 제외한 지피성 동반작물은 배추의 생육에 영향을 미치지 않았다. 배추와 동반작물에 의한 정식 이후의 피복률 변화는 동반작물보다는 배추생장에 의해 주도되었으며, 초기의 생장속도가 빨랐던 긴병꽃풀과 애기기린초 동반작물 재배구에서 초기 피복률 상승이 빠른 반면, 고온기 생장속도가 느린 범의귀와 지면패랭이는 급속한 피복도 증가를 보이지 않았다. 각각의 동반작물의 줄기와 잎의 절단 경도는 범의귀와 애기기린초가 낮은 반면, 긴병꽃풀과 지면패랭이는 매우 높아 내답압성이 우수하였다. 지피성 동반작물과 배추는 광 및 양분 경합성은 거의 없었다. 지피성 동반작물 재배구에서 배추 수관 아래 기온 및 지온은 배추 단독구보다 각각 1℃내외, 0.5~1℃ 낮았으며, 습도는 8% 정도 높았다. 4종 지피성 동반작물을 토양보전성, 경관성, 내성, 생육 등을 고려하여 각 평가요소별 가중치를 두어 평가한 결과, 지면패랭이〉긴병꽃풀〉〉범의귀〉애기기린초의 순으로 높았고, 이중 지면패랭이가 가장 우수하였다.

Our research work aimed to evaluate cover crop effects of winter rye on soil characteristics, soil conservation, and yield productivities on potato fields with 15% slope during a fallowed period. There were two controls of bared field without any cultivation and conventional potato cultivation without winter rye. Potato cultivation increased soil pH, organic matter, available phosphate, and exchangeable cation regardless of cover crop cultivation. Sub-soil, particularly, all components of soil chemical properties showed higher value in winter rye cultivation than conventional cultivation. Higher soil density was observed on cover crop cultivation than conventional cultivation resulting from root residues of the cover crop both topsoil and subsoil. Cover crop residues positively affected plant growth and reduced the amount of soil erosion by holding the soil. Although severe soil erosion was seen in conventional cultivation, winter rye cultivation declined soil erosion by 47% during the fallow period on potato slope fields. Distinct soil bacterial communities were detected among treatments and some OTU(Operational Taxonomic Unit)s showed significantly higher abundance in winter rye treatment. Total yield and commercial rate demonstrated no significant differences while higher tuber phosphate, K+, and Mg2+ contents were observed in winter rye cultivation.

Environment-friendly soybean planting system has been being required in the upland field with high slope and heavy rain in summer season. Changes of weed amount and soybean yield by rye cover crop and conservation tillage were investigated. Soil-disturbing at conservation tillage before soybean planting increased numbers and dry weights of weeds germinated in late spring such as Echinochloa crusgalli P. Beauv (barnyardgrass) and Portulaca oleracea L. (common purslane) regardless of herbicide spray even though the weed, Chenopodium ficifolium Smith germinated before soil-disturbing were higher at non-disturbing soil. Higher weed amounts at plots of strip-tillage (30cm rototilling) compared to minimum tillage (10cm rototilling) was mainly due to the weed increase by soil-disturbing. Soybean yields at plots with rye cover crop, particularly early maturity rye cover crop, were lower than those at plots without rye cover crop, which was due to lower soybean seedling stand by heavy rye residue. More researches are required for the higher soybean yield at the minimum tillage with rye cover crop in which weed amounts were low.