This study was conducted to evaluate soil inorganic N concentrations and N uptake efficiency of sorghum × sudangrass hybrid (Sorghum bicolor (L.) Moench) as affected by organic nutrient sources from 2009 to 2011. The treatments included chemical fertilizer, compost, oilcake, alfalfa hay mulch, and control. Nutrient applications were made at rates equivalent to approximately 210 kg of actual N per hectare. The precipitation during the growth period from May to September was higher in 2011, followed by 2009, and 2010. Oilcake had the lowest C:N ratio in the raw materials. Compost treatment slowed N-mineralization rate in soil during the measured years. Soil mineral nutrition and dry matter production were not consistently affected by treatments, but the dry matter production was negatively correlated with the amount of precipitation from May to September for three years. Chemical fertilizer treatment increased N efficiency in plants in the first two years, observing with lower N efficiency in plants treated with compost for 3 years. Increased precipitation from June to August improved N efficiency in sudangrass plants treated with compost but reduced the efficiency with the chemical fertilizer. Total dry matter production and N efficiency in plants were not affected by the C:N ratio of the raw materials rather than weather condition.

We conducted a survey of actual using conditions of farm-made liquid fertilizers by investigating their formulation types, materials, making processes, using methods and various beneficial effects on 29 farms certified by National Agricultural Products Quality Management Service to produce environment-friendly agricultural products in 2009. Most of the materials used to make liquid fertilizers are those that can be easily obtained around the farms. Molasses or black sugar are added as an energy source of microorganism. And leaf mold, bacterial cultures supplied by agricultural extension centers of local governments, and cultures of native microorganisms were used as microbial sources for fermenting effective microorganisms. Types of the farm-made liquid fertilizers were fermented liquid fertilizers, fermented plant juices, amino acid liquid fertilizers, calcium-liquid fertilizers, and phosphoric acid liquid fertilizers. Effects of liquid fertilizers used by the farms were found to promote plant growth by supplying nutrition, to accelerate blooming and flower bud formation, to enhance the quality of agricultural products such as increase of sugar contents and improvement of storing conditions, to induce resistance against diseases and insect pests, and to cause endurance to high temperature stress. Chemical properties of the liquid fertilizers collected were analyzed. As a result, pH and EC range showed differences according to kinds of the liquid fertilizers. Amount of macro-nutrients, such as nitrogen and phosphoric acid, in most of the collected liquid fertilizers, was found to be low. Even though the liquid fertilizers were made from same materials, their contents was found to be different depending on the making process.

This study was conducted to investigate the changes in physicochemical and microbiological properties during fermenting process of farm-made organic liquid fertilizer made of the mixture of organic materials such as blood meal and molasse during fermenting process. The pH level of organic liquid fertilizer during the fermentation decreased from 7.2 to 4.3. The EC of organic liquid fertilizer was increased from 13.9 dS/m to 99.3 dS/m during the fermentation. The total population of aerobic bacteria decreased from 8.2×105 cfu/ml to 3×104 cfu/ml, but Bacillus spp. increased from 2.1×102 cfu/ml to 4.2×103 cfu/ml during the fermenta-tion. Bacterial isolates were obtained from organic liquid fertilizers and identified by fatty acid-base typing. The Genus Bacillus was dominant as fermenting proceeded. The denaturing gradient gel electrophoresis (DGGE) profile showed changes of bacterial communities in organic liquid fertilizers.

Consumers’ interest and government’s support for the fruits rapidly increased organic fruit productions. This study was examined to compare the soil physicochemical and microbial properties of orchards soil in conventionally and organically management systems. Organic cultivation had lower soil bulk density, solid phase, and penetration resistance than the conventional cultivation. Soil pH and organic matter contents increased from March to August, and the values were greater in the organic cultivation than the conventional cultivation. Total nitrogen (N) and phosphorous concentrations decreased from March to August, and the organic soils had greater N but lower phosphorous concentrations than the conventional soils. Soil microbial carbon biomass increased 36% and 15% for organic and conventional cultivations, respectively, from March to August. Soil microbial N biomass was greater in June than March or August, and the organic cultivation had a greater biomass N compared to the conventional cultivation. Soil dehydrogenase and chitinase activities were greater in June than in March or August. β-glucosidase activity declined in both cultivations, while the phosphatase activity increased. Organic cultivation had greater enzyme activities in March, June, and August, except for the acid phosphatase activity in June.

This study was conducted to develop an organic control of powdery mildews of cucumber by using mayonnaise in green house. The treatment of 0.1~2% mayonnaise resulted in 8.3%~99.2% control efficiencies against powdery mildew of cucumber. 0.5% mayonnaise treatment resulted control values over 97% in disease. It did not adversely affected the photosynthesis of foliages. Although one application of mayonnaise to the foliage was not practically effective enough, two or three application of mayonnaise to the foliage at the 0.5% concentration resulted in excellent control against powdery mildews. This treatment could provide protection for 10~14 days after application. Among the type of mayonnaise, general mayonnaise revealed 97.5% control value, but mayonnaise containing low oil content revealed 39.3%~97.5% control values on powdery mildews at the 0.5% concentration. Therefore, oil content in mayonnaise played a essential material to control powdery mildew. Results indicated that mayonnaise could be used as organic control of powdery mildews of cucumber. This control might be environmentfriendly as well as cost-effective.

동계 피복작물의 파종 시기는 월동 후 회복률과 생산량에 아주 중요한 영향을 미치나, 포장에서 피복작물은 주작물의 수확이 끝난 후에 파종되기 때문에 주작물의 수확이 늦어질 경우 파종 시기를 놓쳐 안전한 월동이 어려울 수 있다. 본 실험에서는 4종의 피복작물에서 파종 시기에 따른 생육의 변화를 알아보았다. 1. 실내 발아 조사를 실시한 결과 모든 피복작물에서 25℃ 와 20℃ 에서는 비슷한 경향을 보였고, 15℃ 이하 처리구에서 온도가 낮아질수록 초기 발아율이 낮게 나타났다. 호밀은 5℃ 에서 처리 4일 후부터 발아를 시작해 처리 7일 후에는 90% 이상이 발아되었다. 2. 월동 전 생육 조사에서 크림손클로버, 알팔파, 헤어리베치는 지상부 길이와 생체중이 9월 파종구와 10월 파종구간에 차이를 보였고, 호밀은 9월 파종구와 10월 파종구 간에 큰 차이가 없어 다른 작물에 비해 내한성이 뛰어났다. 3. 월동 후 생체중은 모든 피복작물이 9월 파종구와 10월 파종구 사이에 차이가 나타났다. 호밀과 헤어라베치는 월동후 지상부 길이가 파종일에 따라 차이가 크지 않았으나, 크림손클로버와 알팔파는 10월 11일 이후 파종구에서 감소했다. 4. 크림손클로버는 10월 4일 이전 파종구에서는 피복률이 80% 이상으로 높게 나타났으며, 이후의 파종구에서는 점차 감소되어 10월 25일 파종구에서는 11.9%로 나타났다. 알팔파는 10윌 파종구에서 파종일이 늦어짐에 따라 피복률이 감소되었으며, 호밀과 헤어리베치는 파종 시기에 관계없이 우수한 피복률을 보였다.