In the field of agriculture, conventional agriculture uses a lot of chemical fertilizers and pesticides, which has a lot of negative effects on the environments in both regional and global scale. Therefore, in terms of environment and sustainability, establishing the low input agricultural system is strongly needed. “Nature Farming (NF)” is one of the low input agricultural systems, which doesn’t use chemicals with no-tillage. Also, the fields were covered by weeds, which might be the key of nutrient cycle in this farming system. The object of this research is to clarify the nutrient cycle on nature farming.

The research was conducted in Ibaraki University. The experimental plot has 4 treatments with 4 replications, which was decided randomly. The treatments consisted of 2 tillage treatments (a)NT+m: no-tillage with weed mulch [“Nature Farming”], (b)CT-m: conventional tillage without mulch, and 2 fertilizer treatments (a)no-fertilizer, (b)fertilizer (2ton/ha of rice bran). The soil samples were taken in each seasons in 2010 and 2011, then soil total nitrogen and inorganic nitrogen was analyzed. Also, the decomposition rate of weeds and the contribution of soil fauna on it were analyzed using litter bag in 2011. In this poster, I’m going to present about them.