Back M. Fujita
International Nature Farming Research Center, Agricultural Experiment Station, 5632 Hata-machi, Nagano 390-1401, Japan
Full Paper (PDF File: 34KB)
Abstract
Oribatid mites, one of the major soil fauna groups in crop fields, were
compared in the abundance and diversity between conventional fields (CT)
and nature farming fields with tillage (OT) or no-tillage (ON) practices.
The values of abundance, species richness, diversity and evenness were
significantly larger in OT and ON than in CT, indicating that the abundance
and diversity were greater in nature farming fields than in conventional
farming fields. The abundance in OT was similar to that in ON, while the
species richness and diversity were smaller in OT than in ON, suggesting
that no-tillage practice under nature farming management might contribute
to the improvement in quality of oribatid communities. Oribatid mites were
classified into three feeding groups. Macrophytophages, microphytophages
and panphytophages feed on dead higher plants, microorganisms, and dead
higher plants and microorganisms, respectively. Only microphytophages were
obtained in CT. The density and species richness were significantly smaller
in CT than in OT and ON. All of the feeding habits were observed in OT
and ON. The density and species richness in each feeding habit were larger
in ON than in OT. Panphytophages were the most abundant in ON, suggesting
that panphytophagous species played a significant role in decomposing soil
organic matter in nature farming crop fields.