Study On Agronomic Characters And Silage Quality Of Different Silage Maize In Northern And Southern Xinjiang

Objective:As the growth period advances,silage maize has a series of changes in its morphological characteristics,nutritional components and water content.There are significant differences in agronomic traits and nutritional quality in different growth periods.To study the changes in agronomic traits and nutritional quality of silage maize in different growth periods,Has guiding significance for the production of silage corn.In view of this,the purpose of this study is to explore the dynamic changes of agronomic characteristics and fermentation quality of silage maize in the southern and northern Xinjiang regions,and to screen the best silage maize varieties and the best harvest period in the three divisions of southern Xinjiang and the Shihezi region of northern Xinjiang.Methods:Using 15 commonly used cultivated silage maize varieties in southern Xinjiang and12 commonly used silage maize varieties in northern Xinjiang as experimental materials,the experiments were carried out in the Sanshi area of southern Xinjiang and Shihezi area of northern Xinjiang.In the silage corn filling period（FS）,1/4 milk line（1/4ML）,1/4 milk line（1/2ML）,3/4 milk line（3/4ML）and maturity period（MS）were measured respectively.The agronomic characteristics of silage corn（plant height,ear height,fresh grass yield,whole plant fresh weight,stalk fresh weight,ear fresh weight and grain fresh weight）were harvested to prepare silage,and its nutritional quality[Dry Matter（DM）),crude protein（CP）,neutral detergent fiber（NDF）,acid detergent fiber（ADF）,soluble carbohydrate（WSC）,starch（ST）,crude fat（EE）]and fermentation quality[p H,lactic acid（LA）),acetic acid（AA）,propionic acid（PA）,ammonium nitrogen/total nitrogen（NH₃-N/N）].Finally,the in vitro gas production method was used to study the gas production within 0-48 h of each silage corn feed in different growth periods,and analyze the organic matter digestibility（OMD）and metabolizable energy（ME）.Result:The results showed that:[Southern Xinjiang]the plant height,ear height,fresh grass yield,fresh weight of whole plant,fresh weight of stem,fresh weight of ear and fresh weight of grain of silage maize increased with the growth period（from filling stage to 3/4 milk line stage）.The contents of DM,WSC and St were increasing,while the contents of ADF and NDF were decreasing,and there were significant differences among different growth stages（P<0.05）.CP content in 3/4 milk line stage was significantly lower than that in other stages（P<0.05）.The p H value and AA content of fermentation index first decreased and then increased,NH₃-N/N and PA content decreased,LA content first increased and then decreased.The OMD decreased,ME increased,and the difference was significant in different growth stages（P<0.05）.There was significant difference in gas production rate among different growth stages（P<0.05）.[Northern Xinjiang]With the development of growth period（from 1/4 milk line stage to maturity stage）,the plant height and ear height of silage maize increased continuously,and the fresh grass yield,whole plant,stem,ear and grain fresh weight increased first and then decreased.The contents of DM,WSC and St increased,while the contents of CP,ADF and NDF decreased.The p H value and NH₃-N/N of fermentation index first decreased and then increased,and LA content first increased and then decreased.The OMD decreased,ME increased,and the difference was significant in different growth stages（P<0.05）.There was significant difference in gas production rate among different growth stages（P<0.05）.Conclusion:（1）considering the agronomic characters,nutritional quality and fermentation quality of whole plant silage maize,the best harvest time of whole plant Silage Maize in Sanshi of Southern Xinjiang and Shihezi of Northern Xinjiang is 3/4 milk line stage.（2）Xinwo 1,Q1901,Tunyu 765,Dafeng 30 and Tieyan 53 were the top five varieties in the three divisions of Southern Xinjiang.The top five varieties in Shihezi area of Northern Xinjiang were Q1901,,Xinsiyu 13,Tieyan53,Xinsiyu 10 and Tunyu 168.