Studies On Intercropping And Mixture Ensilage Of Annual Wild Soybean And Forage Sorghum

Annual wild soybean(Glycine soja Sieb. et Zucc.) has great potential in forage production in Agriculture Region of South China due to its tolerance of high temperature and moisture, great adaptability and fine feed quality. However, the forage yield of monoculture annual wild soybean is low because of the thin and twining stem. But the forage yield of annual wild soybean can be enhanced by intercropping with tall stalk cereals such as sorghum(Sorghum bicolor (L.) Moench) and Sudan grass(Sorghum sudanense (Piper) Stapf.). After the intercrops are harvested, they can be mixed and ensiled. The annual wild soybean-tall stalk cereal mixture silage can not only avoid high buffering capacity and low water soluble carbohydrates(WSC) in annual wild soybean, but crude protein(CP) in mixture silage can also be increased compared to the silage made from cereals alone.Effect of intercropping proportion of annual wild soybean and forage sorghum on forage yields was investigated in order to provide scientific basis for high yield cultivation of annual wild soybean. Influence of mixture proportion of annual wild soybean and forage sorghum, and forage sorghum harvest date on silage quality, and effect of addition proportion of rice bran or wheat bran on silage quality of annual wild soybean were investigated in order to find out practical methods for silage making of annual wild soybean.The results of intercropping trial indicated that, the annual wild soybean forage yield in treatment that 2-row annual wild soybean with 1-row forage sorghum (WS2FS1) tended to increase as compared with annual wild soybean monoculture and the proportion of annual wild soybean forage yield to total forage yield in WS2FS1 was about 10%. The forage yields and climbing heights of annual wild soybean, and the proportions of annual wild soybean forage yield to total forage yield in treatments that 1-row annual wild soybean with 1-row forage sorghum(WS1FS1) and 1-row annual wild soybean with 2-row forage sorghum (WS1FS2) were lower than those in WS2FS1.The results of study on mixture silage of annual wild soybean and forage sorghum showed that, the silages made from forage sorghum alone(FS), 10% annual wild soybean mixed with 90% forage sorghum(WS10FS90), 5% annual wild soybean mixed with 95% forage sorghum (WS5FS95) and 2.5% annual wild soybean mixed with 97.5% forage sorghum(WS2.5FS97.5) had excellent fermentation qualities and there was bad fermentation in the silages made from annual wild soybean alone(WS). The CP of WS10FS90 could be increased compared to that of FS significantly(p<0.05), but WS5FS95, WS2.5FS97.5 and FS didn't differ in the CP content(p>0.05).The results of study on influence of harvest date on mixture silage quality indicated that, with the harvest dates delayed, the changes in fermentation quality of WS10FS90 and FS were not significant(p>0.05), but the CP of silages dropped. On the contrary, the fermentation quality of WS was improved and ammonia nitrogen content dropped, while the CP content of the silage increased. The results suggested that the feasible harvest duration for forage sorghum ensiling was comparatively long at its late elongating stage.The results of research on effect of proportion of rice bran or wheat bran added on silage quality of annual wild soybean showed that, rice bran and wheat bran could improve fermentation quality and nutritive value of silages significantly as compared to silages made from annual wild soybean alone(p<0.05). The fermentation quality of silage with 20% rice bran or wheat bran was not different with that of the silages with 10% rice bran or wheat bran respectively(p>0.05). Rice bran was better than wheat bran in improving wild soybean silage fermentation quality.All results revealed that, annual wild soybean forage yield in WS2FS1 could be improved compared to annual wild soybean monoculture and the proportion of annual wild soybean forage yield to total forage yield in WS2FS1 was about 10%. During relatively long period, forage sorghum was suitable for ensiling at the late elongating stage. The mixture silage made from the above intercropping treatment not only fermented well, but the CP content could be also increased compared to FS. The fermentation quality of the silage made from monocrop annual wild soybean could be improved by adding 10% rice bran or wheat bran.