Montreal Low Price Medium Silicate Sand Making Machine North Kalimantan About 20.80 ha rice field area at the kuningan research station contained low and medium c-organic on 8.68 ha (41.75%) and 12.12 ha (58.25%) area respectively. at muara experimental station, soil c-organic was classified as low and moderate for 8.14 ha (40.72%), and 11.86 ha (59.28%) area respectively