Effect Of Nitrogen, Phosphorus And Potassium Fertilization On Accumulation Of Different Carbohydrate In Silage Corn

As the basic of development of livestock breeding industry, silage corn (Zea mays L.) are high quality feed of cattle sheep and other ruminants. Carbohydrate is an important fermentation substrate, the amount of its content directly affect the quality of silage corn. Different structural style's carbohydrate such as monosaccharide, disaccharide and polysaccharide and so on has different influence on quality of silage. Fertilizater (nitrogen, phosphorus and potassium fertilization) not only directly affects on yield in silage corn, but also on carbohydrate content of different structural style. The experiment utilized Dongqing No1 silage corn as materials to study nitrogen, phosphorus and potassium fertilization on accumulation of varieties carbohydrate in silage corn, and used the gray relevancy theory to evaluate the yield and content of carbohydrate in silage corn in different harvest periods, in order to select suitable usage of nitrogen, phosphorus and potassium fertilization and the best harvest time of Dongqing No.1 silage corn in Harbin region. The main conclusions of this experiment are as follows:1. From milk stage intitial to dough stage telophase, fructose content in the whole plant silage corn was decreased; content of sucrose and total soluble sugars and fresh yield were first increased and then decreased; starch content and dry matter yield tended to increase; content of neutral detergent fiber and acid detergent fiber were first decreased and then increased.2. Obtaining the highest biomass of corn silage, the highest content of fructose, total soluble sugar and starch, the lowest content of NDF and ADF, fertilizer combination was N2P2K₂, that was used nitrogen (N) 200kg/hm², phosphorus (P₂O₅) 100kg/hm² and potassium (K₂O) 112kg/hm².3. Obtaining the highest content of sucrose, fertilizer combination was N2P3K₂, that was used nitrogen (N) 200kg/hm², phosphorus (P₂O₅) 150kg/hm² and potassium (K₂O) 112kg/hm².4. The results evaluated by gray correlation analysis showed that it was best cultivation use way for silage corn that the optimal quantity application was N200 kg/hm², P₂O₅100 kg/hm² and K₂O112 kg/hm² and the optimal harvest period was dough stage initial which the content of total soluble sugars and fresh yield in Dongqing No.1 silage corn were the hightest.