Abstract:
Agriculture is one of the important activities for us to produce foods. Rice production is
considered as a sustainable farming activity due to its thousands of years of history. As of 2018,
rice was produced more than 700 million tons in the world. By region, Asia produces the most
rice and accounts for about 90 % of world production. In Japan, around 100 years ago,
modernization of agriculture (rice farming) such as mechanization and chemical fertilizer
application started, and then, around 70 years ago, large-scale field integration and application
of herbicide started. As a result, rice production was stabilized and increased. However, on the
other hand, rice farming started to show negative impact for the Environment, especially water
quality. Thus, it is a keen issue to evaluate the relationship between rice farming and drainage
water quality influencing downstream water environment, and reduce nutrient loadings from
the fields by managing drainage gate and water depth in the critical periods for water quality
conservation. In addition, it is necessary to remember rice fields are not only the place for
producing food, but also the place for nurturing life by other animals. Thus, it would be great if
we could share the value of rice fields with wildlife, and obtain benefit for rice production from
them, such as organic nutrient inputs. For achieving eco-friendly and sustainable rice farming
with less environmental impact, it is very important to understand their activities in the fields
and evaluate the benefit such as nutrient inputs to the fields and use it in next season. In this
presentation, as examples, research findings for reducing adverse effects from paddy fields to
the Environment are introduced.
