Production of Soiling Rice Herbage and Grain from Regrowth : I. Effects of cropping season and soiling time and height on herbage and grain yields and feeding value

Abstract

With the objectives to develop a simultaneous production system of rice for soiling herbage and for grain from the regrowrth, wre investigated effects of cropping season and soiling time and height on herbage and grain yields and their feeding value. As the soiling time delayed, the herbage yield linearly increased but the grain yield from the regrowth linearly decreased. Later soiling brought a remarkable reduction of crude protein and also a slight reduction of crude fat concentration of the herbage. These concentrations of rice herbage soiled until 30 dayrs before heading were higher than those of average over 6 temperate grasses. The total yields of crude protein and fat summed over the herbage, grain and straw of the regrowth reached a maximum at the soiling of 30 to 40 days before heading and were higher than those of unsoiled rice by 6-28%. The 5cm soiling reduced the grain and straw yields of the regrowth and also crude protein, fat and organic matter concentrations of the herbage, especially at the late transplanting. In conclusion, earlier transplanting and soiling at 30-40 days before heading at the height of 10cm are considered to be an optimum for the total yield of herbage, grain and straw and also for the feeding value of herbage. Under a traditional fertilizer application and planting density, this production system enables us to produce about 1.5 t/ha of herbage and 70-90% of grain yield of unsoiled rice.