Studies on Utilization of Rice Plant and Barnyardgrass as Soiling Crops : 2. Growing rice and barnyardgrass solely as soiling crops under both lowland and upland conditions

Abstract

Japonica, Indica and Java rice varieties as well as barnyardgrasses (Tainubie : Echinochloa crus-galli Beauv. var. oryzicola Ohwi and : Echinochloa crus-galli Beauv. var. caudata Kitagawa) were tested as soiling crops under both lowland and upland conditions, but Japonica upland varieties were tested singly under upland condition. The upland condition was rather swampy by the leaking water from the adjacent paddy field. The results were as follows (Fig. 1 and 2). The total yield of three clippings was slightly more under lowland condition than upland condition except Tainubie. The order of the yield among species was almost the same under lowland and upland conditions. Namely, Keinubie ranked the first, Tainubie, Tetep (Indica) and Danahara (Java) came to the second, CO 13 (Indica) and Nepby (Java) came to the third almost the same yield as Shioji and Tsurugiba (Japonica) and upland varieties (Japonica) came to the last. As for the yield of each clipping under lowland condition, was the top and Tainubie was the last at the first clipping, and Tainubie were superior than the others at the second clipping and there were not so remarkable differences among species at the third clipping. Under upland condition, was the top and there was little difference among others at the first clipping, Tainubie was the highest and upland rice was the lowest at the second clipping, and barnyardgrasses and paddy rice were higher than upland rice at the third clipping. More difference was seen between the yield of each clipping in Tainubie than in other species. Nitrogen content of rice plant was higher than barnyardgrasses and under upland condition all species showed a higher nitrogen content than under lowland condition. Cosequently the yield of crude protein was almost the same between barnyardgrass and rice although the former gave a higher fresh or dry yield than rice. All the species gave a higher yield of crude protein under upland condition than under lowland condition. Cows seemed to prefer barnyardgrass to rice plant depending, perhaps, partly on the former's lower silica content than the latter, but rice plant was also proved to be a good roughage by the digest test using sheep. From these results it can be said that ride and barnyardgrass are suitable as roughages to be cultured on an in drained or swampy land, and that, among the varieties used in this experiment, Keinubie, Tetep and Danahara are considered to be most appropriate.