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[Objectives] To explore effective biocontrol methods for diseases in the process of ginseng cultivation, and develop an efficient and environmentally friendly biocontrol agent. [Methods] In this study, 2 strains were isolated from biogas slurry, and Cylindrocarpon destructans (XF), Fusarium solani (GF), Botrytis cinerea Pers (HM) and Alternaria panax Whetz (HB) were used as test materials. The strains were isolated and identified by dilution plate method, 16S rDNA sequence identification method, confrontation culture method, filter paper method and ultraviolet spectrophotometer method, and the bacteriostatic activity and bacteriostatic rate were tested. [Results] Strain 15 (Sphingomonas) and strain 19 (Pseudomonas aeruginosa) were screened out through identification and analysis, and they grew stably within 8-10 d. The bacteriostatic rates of strain 15 against A. panax and B. cinerea were 47.37% and 43.40%, respectively, and the bacteriostatic rates of strain 19 against A. panax and B. cinerea were 62.30% and 63.27%, respectively. The bacteriostatic activity of the extract of strain 19 increased with the increase of OD600 value, and the bacteriostatic effect was optimal when the OD600 value was in the range of 0.8-1, up to about 70%, so it had a strong biocontrol potential. [Conclusions] This experiment provides convenience for more effective inoculation, establishes a fast, simple and accurate method for the determination of the best bacteriostatic rate of P. aeruginosa culture solution to HM, and lays a foundation for large-scale culture of P. aeruginosa culture solution. Besides, it is expected to provide a theoretical basis for the efficient control of ginseng B. cinerea in field production, use it for the prevention and control of ginseng shoot diseases, and provide a reference for the efficient and diverse development of biocontrol agents for ginseng shoot diseases.

In order to investigate the effects of slurry recirculation technology on anaerobic digestion performance of maize straw silage, maize straw silage was fermented with recirculated biogas slurry, and the gas production, pH value, methane content, volatile organic acids (VFAs) contents, chemical oxygen demand (COD) removal rate and other indicators were studied. The results showed that the fermentation time was positively correlated with daily gas production, methane content, cumulative gas production, VFAs and COD removal rate. Although the pH value fluctuated, it was still in the normal reaction range. The daily gas production was about 1.26 L. The acetic acid content increased first, then decreased, then increased, and finally stabilized. The biogas slurry recirculation technology saves water resources by 40 mL/d without affecting the normal gas production of anaerobic fermentation, and reduces the consumption of environmental resources. It has important development significance for the sustainable use of biomass resources.

To decrease fertilization amount of chemical fertilizer and improve the quality of vegetable crops, spinach was taken as the test material, and the impact of different fertilizer on spinach growth and yield was studied via the manners of biological organic fertilizer and organic fertilizer+chemical fertilizer. Experimental results showed that in the formula of organic fertilizer+chemical fertilizer, chlorophyll and nitrogen contents in spinach leaves obviously increased; in the formula of only adding organic fertilizer, spinach leaf temperature, leaf width, root length, plant height and fresh weight were all better than those in the formula of organic fertilizer+chemical fertilizer, and better formulas were A5, E5, F3 and I5, in which spinach plant height in E5 was 5.63 times higher than G5, root length in E5 was 2.67 times higher than G5, and fresh weight in G5 was 32.6 times higher than G5. By comprehensive analysis, the most suitable formula for spinach production was E5, and the research could provide theoretic basis for fertilization amount of organic fertilizer required by spinach growth and development.

Through analyzing the soil organic matters (N, P, K) of farmland cultivated with different years of Panax ginseng, this paper studied the changes in soil nutrients of farmland with different vertical depths and cultivation years of P. ginseng. Results indicated that the vertical structure was obvious in soil nutrients of farmland with different cultivation years of P. ginseng; in most cases, the soil nutrient content gradually declined with the fibrous roots of P. ginseng spreading downward; the soil electrical conductivity (EC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen, available phosphorus were manifested as surface layer > root layer > bottom layer, while the available potassium was manifested as surface soil and bottom layer > root layer; the soil pH changed in the range of 5.69-6.22, suitable for growth of P. ginseng. It is expected to provide theoretical basis for improvement of soil nutrients of farmland with cultivation of P. ginseng.

In order to explore the substitution substrate for rice seedling on upland fields, this paper uses spent mushroom substrate to study the physical and chemical properties of substrate, enzymic activity and number of tillers during the cultivation of rice seedling on upland fields. The results show that at the three stages of rice seedling cultivation (two-leaf stage, three-leaf stage, four-leaf stage), the content of organic matter and EC in spent mushroom substrate is higher than in the control soil, pH is within the range suitable for the growth of rice, and other nutrients (total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus) are slightly different in different periods; except phosphatase, there are significant differences in urease, catalase and sucrase between spent mushroom substrate and the control soil; the number of tillers under spent mushroom substrate is larger than under the control.

Anaerobic fermentation can increase biomass energy use efficiency of crop straws and realizes win-win of energy and environment. This paper explored the biogas generation performance of anaerobic digestion of cow dung liquid as nitrogen source in three different levels of stirring intensity at 30℃ constant temperature condition. Through pH value, biogas production, chemical oxygen demand (COD), methane content, volatile fatty acid (VFA), principal component analysis (PCA) and modified Gompertz model, effects of agitating intensity on anaerobic digestion performance of corn straw silage were evaluated. Results indicate that the COD removal rate of three agitating intensity levels is higher than 85%, and pH value is about 6.5; the cumulative biogas production after 20 days is 2 h ＞ 4 h ＞ 1 h of agitating; in the 49th day, the biogas production is 1.9 L at 30 min / 2 h, 1.7 L at 30 min / 4h, and 1.6 L at 30 min / h; the maximum biogas production rate is 30 min / 2 h ＞ 30 min / 4 h＞30 min / h; and the maximum methane production rate is 30 min / 4 h ＞ 30 min / 2 h ＞ 30 min / h; in the same energy consumption, the biogas production at 30 min / 4h is higher than 1 h. In conclusion, overall analysis of energy consumption and economic factors indicate that 30 min/ 4 h agitating intensity is more suitable for straw biogas fermentation project. This study is expected to provide theoretical foundation for biogas fermentation project.

朝鮮総督府は，1931年の「満州事変」以降，東亜勧業株式会社(以下東亜勧業)を通して，1932年から1935年にかけて，「満州」に五ヵ所の「安全農村」を建設した。1945年に「安全農村」は日本の敗戦により「満州国」とともに崩壊した。その歴史は今からそれほど遠くない70年前のことであるが， 実際に五ヶ所の「安全農村」でのフィールドワークを通して，「安全農村」に関する記憶が継承されず風化していることを痛感した。「安全農村」を検討対象にした研究は，さほど多くはない。「安全農村」は，これまでの先行研究においては，文献資料によるマクロの視点で考察されてきている。筆者は先行研究での論考を踏まえたうえで，本稿で朝鮮人移民一世（以下移民一世）のライフ・ヒストリーによるミクロの視点で「安全農村」について考察したい。「安全農村」で暮らし，体験したライフ・ヒストリーは，移民一世の個人史でありながら，彼らを取り巻くその時代の社会史でもあると考える。本稿の目的は，「安全農村」で暮らした移民一世の証言に基づき，「安全農村」の建設から瓦解に至るまでの事態の細部を明らかにし，「満州国」の社会史の一断面を照らし出すことである。

Based on the present situation and problems concerning ginseng cultivation as well as soilless cultivation features, we analyze the growth indicators and input-output ratio of different ginseng cultivation patterns, and conform that the soilless cultivation technology for organic ginseng is feasible. And this technology provides theoretical basis and technological feasibility for the sustainable development of ginseng industry.