Anaerobic digestion has recently attracted all over the world and Korea also shows no exception. The major benefits of anaerobic digestion are energy production, water pollution control, pathogen reduction and effective manure production. In Korea it was recognized in late sixties that there was a positive need to find alternative energy for farmers household. The main traditional energy sources in rural area were crop residues and forestry products. Therefore Office of Rural Development through its Rural Guidance Bureau disseminated about 29,000 household biogas units from 1969 to 1975 to provide cooking fuel for farmers household and to improve the mode of farmers living standards. The units were welcomed by farmers at that time. Now, however, most of them are not using due to a number of reasons associated with cold winter and some techno-economical problems (in those day, fossil fuel was quite expensive to compare with other prices and since then farmers income was quickly increased). The author studied on bag type household biogas plant to solve some technical problems of existing household biogas plants, but this also has little appeal for the farmers. From 1977 author studied on village scale biogas plant with two pilot plants. From the viewpoint of energy production, COD removal, kill rate of pathogen and fertilizer value, the results obtained from the experiments were quite promising, but the construction cost of the village scale biogas plant was too high for the farmers in Korea. To find most suitable biogas plant for farmers in Korea through the simplifying the biogas digester, the author developed batch-load biogas plant. By feeding coarse crop residues and manures, total solids concentrations of the batch-load biogas plant are about 28 percent which is much higher than continous digester of 5-8 percent. The batch-load biogas plant was welcomed by many farmers in Korea when it was reported on TV and newspapers. The plant was disseminated 154 units in 1982, 766 units in 1983 and 812 units in 1984 as a promissing project. Besides these biogas plant experiments, studies were also conducted 1) to determine gas production rate with agricultural wastes, 2) to evaluate the effect of loading rate, dilution, retention time on biogas production, 3) to project the amount of potencial energy from agricultural wastes.

In order to improve feed values of Korean agricultural by-products, various treatments including physical, chemical, physicochemical and fermentation were suggested in th is review article. Physical treatments such as chopping, grinding and pelleting reduce partiole size of agricultural by-products, and increase passage rate from the rumen, thus may increase voluntary feed intake and weight gain. Digestibility and voluntary feed intake of straw, rice hull and sawdust, also, may be increased by chemical treatment using sodium hydroxide or ammonia. Especially, because nitrogen content of by-products increase and toxic problem is not posed by ammonia treatment, it's practical usage is recommended in Korea. Silage or fermentation treatment using principles of microbial fermentation may improve palatability of low quality by-products. As mentioned above, it is concluded that various treatments suggested are desirable and improve feed value but may raise several problems. Unfortunately, because cost for installation and products is great and processing work is complicate, farmers are not using well these processing methods until now. Therefore, in order to increase the practical usage at farm level, it is thought that many research works be achieved for efficient process which have simple operation and low installation cost.

속성수로서 현재까지 이용연이 그리 넓지 못한 활엽수(闊葉樹)를 이용(利用)한 당화액(糖化液)으로 단세포단백질(單細胞蛋白質) 생산(生産)에 의(依)한 사료화(飼料化) 전환(轉換)에 관(關)한 기초적(基礎的)인 몇가지 실험(實驗)을 한 결과(結果)는 아래와 같다. Aspergillus niger sm-10, Irpex lacteus, Tricoderma viride sm-6 3균주(菌株)의 셀룰라아제 역가(力價)를 비교(比較)해 본 결과(結果) Tricoderma viride sm­6 의 역가(力價)가 가장 높았으며, 이들을 combination하였을 때에는 상조에 의한 역가상승(力價上昇)(Synergistic effect)은 보이지 않았다. T. viride sm-6의 배양학적(培養學的)인 면을 살펴본 결과(結果) 밀기울배지에 질소원으로서 proteose peptone, 유도제 (inducer)로서 Tween 80, cellulose를 첨가(添加)했을때 역가증가(力價增加) 현상(現象)이 나타났으며 이와 같은 배지에서 배양시(培養時) C.M. Cellulose와 Filter paper 분해 효소역가(酵素力價)는 120hr에 최고에 도달(到澾)했다. 기질(基質)에 효소(酵素)를 반응(反應)시켜 당화액(糖化液)을 생성(生成)하는데 있어서 전처리(前處理)를 한 기질(基質)은 대조주에 비해 약 40%의 환원당 증가(增加)를 보였고, 또한 기질입자(基質粒子)가 작을수록 환원당 증가현상(增加現象)을 보였으며 글루코스 등의 당(糖)은 반응액중(反應液中) 적은 농도(濃度)에서도 커다란 feed back inhibition현상을 나타냈다. 기질(基質)을 rehydralysis시에는 약 31%의 환원당 전환율(轉換率)을 보였다. 이때 당화액(糖化液)을 정량해 본 결과(結果) glucose : xylose의 양이 1.77:1로서 glucose의 양이 많았다. 여기에 단세포(單細胞) 단백질(蛋白質)을 생산(生産)할 목적(目的)으로 부식토, 퇴비, 수액, 토양등의 42점의 시료로부터 xylose 자화성 효모(酵母) 13균주(菌株)를 선별하였으며 그때의 우수균주(優秀菌株)로서 3개균주(個菌株)를 선발(選拔)하였다. 이들 분리주의 배양학적(培養學的) 특징(特徵)을 살펴 본 결과(結果)는 다음과 같다. 1. 분리주중(分離株中) CHS-2, CHS-3, ST-40, CHS -12, CHS-13 균주(菌株)가 당화액(糖化液)을 잘 자화함을 알았다. 2. 분리균주중(分離菌株中) CHS-13 균주(菌株)의 생육도(生育度)가 가장 양호하였으며 초기 최적 pH는 4.4이었으며 최적온도(最適溫度)는 $30^{\circ}C$이었다. 3. CHS-3 균주(菌株)의 specific growth rate는 $0.23\;h^{-1}$, generation time 은 3.01h이었다. 4. CHS -13균주(菌株)의 기질소비율(基質消費率)은 81%이었다. 5. CHS-13 균주(菌株)의 형태학적(形態學的) 배양학적(培養學的) 특성(特性)을 조사(調査)한 결과(結果) Candida guilliermondii var. guilliermondii 로 동정(同定)되었다. 6. CHS-13 균주(菌株)를 당화액(糖化液)에 배양(培養)시켰을 때 Lowry-protein 함량은 $0.72\;mg/m{\ell}$ 이었으며 , yeast extract 첨가(添加)하여 배양시(培養時)는 yeast extract 농도(濃度)가 증가(增加)함에 따라 단백질(蛋白質) 함량(含量)도 증가(增加)하였다. 7. CHS-13 균주(菌株)의 RNA 함량(含量)은 $4.92{\times}10^{-2 }\;mg/m{\ell}$이었으며 yeast extract 농도(濃度)가 증가(增加)함에 따라 증가(增加)하다가 농도(濃度) 0.2%에서 최대함량(最大含量)을 나타내고 그후는 감소(減少)하였다.

양송이 재배(栽培)에 있에서 볏짚을 주재료(主材料)로 사용(使用)할때의 퇴비재료(堆肥材料)의 배합(配合), 야외퇴적(野外堆積) 및 후발효(後醱酵)에 관(關)한 시험(試驗)과 볏짚을 이용(利用)한 느타리버섯 재배(栽培)에 관(關)한 연구(硏究)를 수행(遂行)한 바 그 결과(結果)를 요약(要約)하변 다음과 같다. 가) 합성퇴비배지(合成堆肥培地)의 탄소원(炭素源)으로서 볏짚은 보리짚과 밀짚보다 발효(醱酵)가 신속(迅速)하고 퇴비(堆肥)의 전질소함량(全窒素含量)이 높으며, 배지(培地)의 질(質)이 양호(良好)하여 양송이 자실체수량(子實體收量)이 현저(顯著)히 높았다. 나) 보리짚퇴비(堆肥)는 볏짚퇴비(堆肥)보다 생산성(生産性)이 낮으나 보리짚과 볏짚을 50:50으로 혼합(混合)하면 볏짚과 대등(對等)한 수량(收量)을 얻을 수 있었다. 다) 퇴비배지(堆肥培地)의 전유기태질소(全有機態窒素)와 자실체수량간(子實體收量間)에는 정(正)의 상관(相關)이 있으나 암모니아태질소(態窒素)와는 균사생장(菌絲生長) 및 자실체수량(子實體收量)에 부(負)의 상관(相關)이 있었다. 라) 볏짚을 주재료(主材料)로 사용(使用)할때 무기태질소원(無機態窒素源)으로서 요소(尿素)가 가장 좋았고 유안(硫安)과 석회질소(石灰窒素)는 부적당(不適當)하였다. 요소(尿素)는 3회(回) 분시(分施)할때 손실(損失)이 감소(減少)되었고, 퇴비(堆肥)의 질소함량(窒素含量)이 증가(增加)하였다. 마) 유기태영양원중(有機態營養源中) 들깨묵, 참깨묵, 밀기울, 계분등(鷄糞等)의 첨가(添加)는 퇴비(堆肥)의 발효(醱酵)를 양호(良好)하게 하고 자실체수량(子實體收量)을 증가(增加)시켰다. 바) 양송이 볏짚퇴비(堆肥)를 제조(製造)할때 터널기계화(機械化)하므로 수량(收量)이 13 % 증수(增收)되었고,생산비(生産費)가 34 % 절감(節減)되었다. 사) 볏짚과 밀짚을 이용(利用)하여 느타리버섯 재배(栽培)가 가능(可能)하고 자실체수량(子實體收量)을 뱃짚구(區)에서 높았다. 아) 느타리버섯 볏짚배지(培地)를 $60^{\circ}C$로 6시간(時間) 열처리(熱處理)하므로서 균사생장(菌絲生長)이 양호(良好)하였고 자실체수량(子實體收量)이 높았다.

As in many other country, the use of organic matter in Korea has long history. Farmers understand the value of organic matter as the source of plant nutrient and soil improving agent in general. Since 50 years ago, the sources of organic matter in paddy soils were compost, rice and barly straw, green manure, animal waste, fish and beancake, etc.. Application of green manures such as vetch and chinese milk vetch showed no significant effect on the yield of brown rice in paddy soil. On the other hand, the effects of compost and rice straw showed more significant on the yield of brown rice in paddy soil. Application of rice straw in rice cultivation is commonly made at different times between harvest, early spring and several weeks before transplanting. Considering the suitable paddy soil for application of rice straw under well to moderately well drained soil, the yield was pronounced more than poorly drained soil. Based on laboratory and field experimants, application of rice straw promoted the decrease of oxidation-reduction potential in well to moderately well drained soil. This results to be enhanced the release of some mineral nutrients,. such as potassium, calcium, silicon, and increase of availability of soil phosphorus. In the field experiments, results obtained from nitrogen fraction on the immobilization-mineralization of the tracer nitrogen applied in paddy soil,the amount and index of organic nitrogen incoporated in soil was more pronounced in rice straw application than control. Rice straw and its transformation products incoporated in the soil, provided the inflow of energy necessary to maintain heterotrophic microbes activities. Rice straw and its transformation products, especially soluble carbohydrate, enhanced the population of free-living heterotrophic $N_2$ - fixing microbes. Moreover, rice straw and its transformation products in paddy soil, enhanced the activities of soil enzymes such as dehydrogenase and urease.

An increased population and rapidly expanding industrial development have led to enormous amounts of various domestic and industrial wastes. The proper disposal of ever-increasing wastes is a growing global problem. Land treatment is one of the rational approaches that are environmentally safe and economically practical. It has long been practised in many sites. Recycling of industrial wastes on agricultural land can provide better possible means for maintaining environmental quality and utilizing waste-resources. Even though industrial wastes are beneficial as soil amendment and fertilizer, they have some limitation on land application because of wide variability as well as physicochemical problem in their composition. A direct application of solid and liquid wastes on land is being practised in Korea and some experimental results are presented. The direct application of fermentation waste on rice resulted in a 6 percent yield increase. Another organic residue from glutamic acid fermentation is widely used not only as a direct application as a liquid fertilizer but also for a raw material of organic compound fertilizer. These wastes are much promising as sources of plant nutrients, since they have large amounts of nutrients, especially nitrogen with few toxic metals. On the other hand, fertilizers developed from inorganic industrial wastes include calcium silicate, calcium sulfate and ammonium sulfate. The calcium silicate fertilizer simply produced from slag, by-product of iron and steel manufacturing plant is one of the most successful example of the conversion of wastes to fertilizer and slag production capacity totals to over three million MT/year. About 200,000 MT of calcium silicate fertilizer is currently applied in the paddy rice every year. Calcium sulfate, a waste from the wet phosphoric acid process is to some extent used as a filler of compound fertilizers but quite large quantites are directly applied for the reclamation of tidal flat.

Although traditional Korean diet consists of Very little fats and oils, the increase of their consumption, especially vegetable oil, has been truly remarkable in recent years and this increase is attributed to the improvement of their dietary habit and the development of Korean food industry. On the other hand, domestic production of the edible vegetable oil did not increase at all. Naturally, foreign exchange (over a several hundred million U.S. dollars) is annually used in importing oil seed and/or oil per se. Under these circumstances, it is of utmost importance to maximize the domestic production of edible vegetable oil, although its complete self-sufficiency cannot be achieved. In this seminar, intake of fats and oils by Korean people, status and outlook of the domestic production and consumption of fats and oils will be discussed, with. emphasis on the utilization of agricultural by products and waste as a source of fats and oil.