본 연구는 호밀→옥수수→연맥 작부조합에서 소 및 돼지액상분뇨를 시용수준을 달리하여 연용하였을 때 각 작물의 건물수량, 질산태질소 함량 및 토양특성 변화를 구명하고자 수행하였다. 전체적인 건물수량 비교에서는 소 및 돼지액상분뇨구 모두 시용수준을 100% 이상 증량 시용하였을 때 대조구(화학비료표준구) 보다 높았으며, 식물체 중 질산태질소 함량은 호밀 및 옥수수의 경우 전체 시험구 모두 0.15% 이

Wind load is known to be one of major forces to influence the stability of agricultural structures. General flow fields were calculated to determine flow characteristics over the envelop of the following three types of greenhouses with arched roof : single span, twin span greenhouses, and two single span greenhouses apart 3m inbetween. Pressure coefficients along the envelop of greenhouse were numerically calculated by the k-ε turbulence model, which lead to determine wind forces on it. Curvilinear coordinate for an arched roof and the upwind scheme were adopted for the study. The calculated pressure coefficients were validated with the avaliable data of Japanese Standard and NGAM Standard. The Magnitude of calculated forces over the envelop was not in good accordance with data except the windward wall. Even tile data of Japanese and NGAM Standard for validation deviated a lot from each other in quantity and quality. Such discrepancy may be attributed to different geometric and/or flow configuration conditions for experiments, or the insenstivity of the k-ε turbulence model to recirculation flow.

A sundry system is one of popular systems for composting livestock manure, of which main honest is to utilize unlimited, clean, and free solar radiation. A sundry system with a composter of two horizontal screw-type concrete ducts at different height, was constructed and operated for three days for each test in May, 1993, to evaluate its composting performance. Four treatments of the mixture ratio of swine manure and saw dust (manure : sawdust= 1 : 1.25, 1 : 1, 1 : 0.7, 1 : 0.5) were implemented to evaluate the effect of the mixture ratio on degradation of the composting materials of a sundry system with a screw-type composter. Maximum temperature of the composting materials was over 50℃ at D1 or D2 (one or two days after operation starts) for each test. Mean C/N ratio and water contents of the materials were reduced by more than 15 and 20％, respectively. Microbial density of each test showed a typical variation with the lapse of the composting time. Mesophilic microorganism seemed to play more important role on degradation of the materials than thermophilic. A sundry system with a screw-type composter can be considered as a feasible system on basis of maturity data. The conclusion was completely reverse from that of Choi et at., although both adopted a sundry system. A further study is recommended to pursue the cause of better performance of the screw-type composter, whether it was due to affirmative weather or more efficient composter.

Environmental impact assessment survey reflecting farmers` opinion on the residence and production space in rural settlement area by ORD showed that more than 86% of respondents thought their reservoirs and waterways (small rivers) were getting seriously contaminated primarily by garbage and livestock manure. A typical rural settlement unit was taken to assess the impact of improper management of livestock manure in the farms on the water quality of small river flowing down along the villages where swine and dairy farms were situated in Daejook 2, 3-ri, Seolseong-myun, Icheon-gun. Nitrogen compounds such as NO3-N, NO2-N, NH3-N, and phosphorus compound HxPO4, DO, BOD5, COD, and microbial density were analyzed to evaluate water quality at five test sites designated along the water stream. Tests showed. for example, BOD5 at site 4 was average 9.2mg/l which was about 3~8 times higher than that of observation site 2 and 3, at which most livestock houses were situated. This is a clear evidence that the nutrients of livestock manure illegally discharged to small river can lead to an eutrophication of the river at downstream. A soil absorption system with aeration could be one of alternatives to treat the contaminated wastewater by livestock manure. The place at downstream, inbetween observation site 1 and 2, could be the best construction site for the treatment facility from the standpoint of the overall treatment efficiency, An enclosed composting system can also be regarded as a good alternative for treatment of the sludge which is the by-product of the soil absorption system operation.