Studies on Herbage Production and Nutritive Value of Soiling Paddy Rice : II. Effects of the variety and fertilizer application on the herbage yield, silage quality and the feeding value of whole crop silage

This study was conducted to determine if the types and varieties of paddy rice (Oriza sativa L.) under different fertilizer application are related to herbage yield, silage quality and feeding value. Two Japonica varieties (Kinmaze and Matsuyamamii), three Indica ones (Ambar, British Honduras and Gaiya Dhan Tosar) and Sen one belonging to Chinese paddy rice (Peikuunen) were used for this examination. Those paddy rice were transplanted in submerged paddy field and then, hervested at the milk-ripe stage for whole crop silage. Each silage quality was estimated by the FLIEG's method and each digestibility of chemical composition was also examined by the conventional collection trial with three sheep. The results are summarized as follows. 1) The Indica varieties including Peikuunen ripened earlier and had longer culm than the Japonica one. Peikuunen and the Indica varieties except British Honduras at the ripenning stage lacked in ability of lodging resistance. The fresh forage yield was more in the Indica varieties including Peikuunen than in the Japonica ones. However, dry forage yield was more in the Japonica varieties and Peikuunen than in the Indica ones. Matsuyamamii, the Japonica varirty, which showed the highest yield among varieties was about 145kg of dry forage yield per are in heavy dosage of fertilizer application. 2) The contents of NFE and water soluble carbohydrate of the Japonica varirties in ensiled material were higher than those of the Indica ones including Peikuunen. While the crude ash and SiO_2 contents of the former was lower than the those of the latter. 3) The silage qualities were ranked either "excellent grade" or "good grade" by the FLIEG's method. Each silage quality of the Japonica varieties and Peikuunen was supperior to that of the Indica. 4) The digestibilities of crude protein and crude fiber were higher in heavy fertilizer application than in standard one. Each NFE digestibility of Gaiya Dhan Tosar showed the lowest value among both fertilizer treatments examined. 5) DCP content of silages were higher in heavy fertilizer application than in standard one. TDN contents ranged from 49.5 to 58.2% in standard fertilizer application and from 54.4 to 58.9% in heavy one. 6) TDN yield of silage ranged from 43.2 to 61.3kg per are in standard fertilizer application and from 51.1 to 75.2kg per are in heavy one. The digestible nutrient yield (TDN) of the Japonica varieties were higher than those of the Indica ones. 7) This study has shown that silage of the Japonica varieties and Peikuunen were higher forage yield and digestible nutrient yield than those of the Indica ones, but, Peikuunen at the ripenning stages was lodged easily by visiting of typhoon and evening showers. From above mentioned results, it is recommended that the Japonica varieties with longer culmed and late ripenning, such as Matsuyamamii, suited for whole crop silage of paddy rice in warmer districts of Japan.