논문 상세보기
pp.189-194
추파연맥-옥수수 이모작 작부체계에서 헤어리벳치 녹비 이용의 가능성 및 그 효과를 검정하기 위해 1999년 및 2000년의 2년간 작물시험장 발포장에서 옥수수 수확 후 9월 초순 연맥과 헤어리벳치를 혼파하여 11월 초순 일차적으로 사초를 수확하고 난 후 월동한 벳치를 옥수수의 녹비로 이용하였을 때의 효과를 조사하였는데 다음과 같은 결과를 얻었다. 옥수수 단작에서 벳치단파에 따른 옥수수에 대한 2년 평균 벳치녹비량 6.7cm/ha의 효과는 연맥이모작의 옥수수 질소표준비와 거의 동일하였다. 연맥과 혼파시의 벳치의 녹비 및 녹비질소량은 벳치 단파시의 40%에 불과하여 옥수수 6엽기에 조사한 토양질산태 질소량도 벳치-녹비구 및 연맥-표준질소구보다 반 이하로 감소하였고 식물체 질소함량이 많이 감소하여 출사기 옥수수 질소흡수량이 40-50kg/ha 감소하였다. 그러나 옥수수 6엽기에서의 토양질산태 질소가 무질소비료구의 2배 정도였으며 시험 2년차에는 추비질소가 필요없이 토양 질산태 질소수준인 25mg/kg에 거의 접근하였으며, 출사기에서의 옥수수 질소흡수량이 무질소비료구보다 약 30-40kg/ha 증가하였다. 시험 1년차 연맥+베치-녹비구의 옥수수 전건물중은 벳치-녹비구 및 연맥-표준질소구보다 종실중이 다소 감소하여 약 2 ton/ha 정도의 수량 감소가 있었지만 시험 2년차는 동일하였다. 옥수수 1년차에 약 60kg/ha, 2년차에 20kg/ha 감소하였으며, 연맥-무질소구에 비해서는 1년차 30kg/ha, 2년차 45kg/ha 정도 증가하여 질소화학비료 50-100kg/ha 대체효과를 얻을 수 있었으며, 뚜렷한 녹비의 2년 누적효과를 볼 수 있었다. 따라서 옥수수의 단작시의 헤어리벳치녹비보다는 효과가 적지만 연맥 이모작시에도 연맥과의 혼파에 의한 헤어리벳치의 녹비 및 질소비료 절감효과도 충분히 크며 녹비의 누적효과도 기대할 수 있을 것으로 판단되었다.olice billeting area, sports area, and rear rest area. The entrance space, Podori plaza, and symbolic court on the south-west part of the site represent the publicity of the site as the concept of "open space." On the contrary, considering the specialty of police affairs, the north-east part of the site, which contains the police billeting area and rest area, were designed to maintain security by using the concept of "closed space." To express an identity of the KPA, ′Podori′, a police mascot, the plaza was designed and is suppose to function as the hub of the community. In the front section of the plaza, a symmetrical planting pattern, centering the strong axis, was introduced to strengthen its symbolic meaning. Traditional window frames such as the pattern of ′Pisal-jige′and ′′Umulsal-jige′ were used for the paving system which is applied as the environment friendly design. Site facilities and furnitrue were placed at every i
It is possible to use hairy vetch as green manure for corn not only in corn single cropping but also in double cropping system of corn and fall oats. Fall oats and hairy vetch were mixed-sown after corn harvest and harvested as forage in the early of November, and then hairy vetch stubble was over-wintered and incorporated into soil at corn planting as green manure without N fertilizer (FO+HV-GM). Other treatments were fall oats without N fertilizer on corn (FO-0N) and with N fertilizer 200kg/ha on corn (FO-200N), hairy vetch green manure without N fertilizer on corn (HV-GM), and fell winter follow without N fertilizer on corn (WF-0N). Soil nitrate content, corn growth and nitrogen uptakes, and yield of corn were measured and compared during 2-year experimental seasons. Dry matter and N amount of hairy vetch at the plot of FO+HV-GM were 60% less than those at the plot of HV-GM. The N effect of hairy vetch green manure on corn at the plot of HV-GM was similar to that at FO-200N plot for two years. Soil nitrate at the plot of FO+HV-GM was below the half of those at plots of HV-GM and FO-200N at 6-leaf stage of corn. N uptake of corn at the plot of FO+HV-GM at silking stage was 30% less than those at plot of HV-GM and FO-200N. However, soil nitrate at 6-leaf stage of corn and the amount of nitrogen uptake of corn at silking stage increased two times and 30-40 kg/ha, respectively, compared with those at the plot of FO-0N. Corn yield at FO+HV-GM decreased about 2 ton/ha due to the decrease of corn grain weight in the first year compared with plot of HV-GM and FO-200N, but its difference was not shown in succeeding second year. Corn N uptake at FO+HV-GM decreased 60 kg/ha and 20 kg/ha in 1999 and 2000, compared with plot of HV-GM and FO-200N, respectively, but increased 30kg/ha and 45kg/ha compared with the plot of FO-0N in 1999, 2000, respectively. Therefore, it is estimated that hairy vetch green manure in fall oats-corn double cropping system can reduce nitrogen chemical fertilizer on corn as much as 50-100 kg/ha although its N effect is much lower than the N effect of hairy vetch green manure in corn single cropping of which N effect is over 200 kg/ha.
