Institute for Agro-Environmental Sciences, NARO

Elucidating the relationship between biodiversity and organic & low input farming

NARO has clarified the existence of more plants and animals in organic and low input agricultural chemical rice fields than in conventional farming field by means of a national scale field survey. This research result helps to mitigate the negative environmental impacts through biodiversity-friendly rice farming and also helps to add new value to agricultural products through branding using biodiversity.

Overview

Agriculture is not solely meant for producing food and living materials. It has multifaceted functions including the conservation of biodiversity in farmland and its surroundings, and the entire population receives the benefits (ecosystem services). Environmentally friendly agriculture such as organic farming and low input agricultural chemical farming is attracting attention as one of the means to realize sustainable agricultural production in consideration of biodiversity. However, research to verify the effect scientifically is limited to a case study in one area, and verification based on a survey of biodiversity in a wide-area rice field has not been conducted yet.

Therefore, a research group including NARO researchers conducted a nationwide survey of living creatures in both organic & low input farming rice fields and conventional rice fields and the number of species and number of individuals(population) are compared. From the survey it was revealed that the number of endangered plant species and natural enemies of pests such as of Tetragnatha spiders, Sympetrum dragonflies, Pelophylax frogs, and waterbird species such as heron etc., was found to be more in organic rice field compared to conventional rice field. It was found that rice fields with low input of agricultural chemicals have more plant species and Tetragnatha spider population than conventional cultivation paddy fields, while the number of Hyla japonica frogs are less. In case of Hyla japonica frogs and Cobitidae loaches, it was found that the specific management practices greatly affected the population rather than reduced usage of chemical fertilizers and chemical pesticides.

Publication

Katayama N, Osada Y, Mashiko M, Baba YG, Tanaka K, Kusumoto Y, Okubo S, Ikeda H, Natuhara Y (2019) Organic farming and associated management practices benefit multiple wildlife taxa: A large-scale field study in rice paddy landscapes. Journal of Applied Ecology, 56: 1970-1981.

Reference Information


Fig.1 Summary of this research result

We found that organic farming, followed by Low input farming, has large number of species or individuals in multiple organism groups than conventional farming. Also, the impact of specific management practices varies greatly depending on the organism group.
1 For plants number of species, for birds number of species and individuals and number of individuals for the other organism are evaluated.
2 The number obtained by adding the number of types of components included in each herbicide.
3 Neonicotinoid or phenylpyrazole



Fig.2 Relationship between organic rice field proportional area and
number of waterbird species and individuals.

It was found that the larger the area of organic rice fields, greater the number of species and individuals of waterbird such as herons. The solid line shows the estimated number of species and individuals while the gray represents the 95% confidence interval.

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