Studies on Sustainable Agriculture and on Genetic Resources

1.环境保护与农业可持续发展：通过对我国利用土壤有益微生物防治土壤病害的现状进行调查，探索出一种新的防治方法。本文还对中国特有昆虫种类进行了调查，并与日本的生态足迹进行了比较。此外，还考察了当地最常见的种蛋品种--绍兴鸭的饲养场，以了解其饲养制度和管理方法。母鸡用特定的饲料混合物喂养，并补充在邻近河流中生长的水葫芦（凤眼莲），排泄物被丢弃到河里。这种管理系统非常有效地利用了当地的环境条件，但劳动效率不高：8,000只母鸡由三名员工饲养。虽然这种相当传统的管理符合区域环境保护，但如果农场计划进行大规模饲养和生产，就需要改进。2.新的遗传资源的开发和应用：杂交水稻品种的培育是为了提高水稻产量和品质。目前，中国种植的水稻超过50%是杂交品种，预计每公顷稻谷产量将高达0. 1吨。对于种子收集，预计需要1/100或1/200形成的育种场以进行充分的种子收集。在浙江和安徽两省的沿着山地高地地区，水稻种植在河岸的稻田或山坡的梯田里。玉米、大豆和甘薯都是在山脚下的高地上种植的。玉米与小麦或大麦轮作，在三年内生产四种作物，这使农民能够维持粮食生产以维持生计。

1. Environmental protection and sustainable agriculture : Current methods of controlling soilbome diseases using beneficial soil microorganisms in China were investigated to develop a new technology for pest control. Also studied in this context were survey of indigenous insect species in China and their ecological trails in relation to those in Japan. Besides, the poultry farm raising Shaoxing duck, the most common species for egg production, was visited to study their feeding system and management for the conventional livestock in the region. The hens were fed with a specific feed mixture supplemented with water hyacinth (Eichhornia crassipes) growing in an adjacent river, and the excretions were discarded into the river. This management system exploits the local environmental condition very effectively but is not labor-efficient : 8,000 hens are raised by three employees. Although this rather traditional management is in accordance with regional environmental conservation, improvements will be needed if the farm plans to operate mass raising and production. 2. Exploration of new genetic resources and their applications : Hybrid rice cultivars have been bred to improve yield and quality of rice production. Currently, more than 50 % of rice growing in China is hybrid cultivars, and the yield of unhulled grain is expected to be as high as 0.1 tons per hectare. For seed collection it is expected that a breeding field in a 1/100 or 1/200 formation is needed for adequate seed collection. In the region of mountainous highlands along rivers in Zhejiang and Anhui Provinces, rice is grown in paddies in riverbanks or terrace on the hillsides. Maize, soy bean and sweet potato are grown in upland fields in foot areas of mountains. Maize is rotated with wheat or barley to produce four crops in three years, which allows the farmers to sustain food production for their subsistence.