Effect Of Silicon Fertilizer On The Growth And Quality Of Alfalfa Under Drip Irrigation

Alfalfa (Medicago sativa L.) is a perennial legume herbs of the genus Medicago. Alfalfa has high nutritional value and good palatability. It has widely ecological adaptability and highly output. Alfalfa lives long and it is a green manure planted in the fall. Alfalfa can improve the quality of farmland and increase soil nitrogen content. It is widely used as forage for livestock. Alfalfa is known as "the king of forage" reputation. In order to explore the influence of integration of irrigation water and fertilizer on the growth and quality of alfalfa under drip irrigation (SDI), the pot culture experiment and field experiment were carried out. The pot culture experiment had four treatments of silicon concentrations (SO,S1,S2,S3) and five duplicates for every treatment. The field experiment had five treatments of silicon fertilizers concentration (CK, S1, S2, S3, S4) and three duplicates for every treatment.1. The potting experiment showed that six growth indexes of alfalfa applied silicon fertilizer were higher than that of without silicon fertilizer. As for the quality of alfalfa hay, CP with 0.02 g· kg-1 silicon fertilizer was the highest, NDF with 0.02 g·kg-1 silicon fertilizer was the least. So the conclusion was that the integration of irrigation water and silicon fertilizer under subsurface drip irrigation can promote growth of alfalfa and silicon fertilizer promote the early growth stage of alfalfa more than the late growth stage of alfalfa.S2 plants has higher quality than other plants.2. The field experiment showed that silicon fertilizer was positive to promote alfalfa growth. Compared S1, S2, S3 and S4 to CK, the leaf areas increased 68.0-117.2% and 37.9-133.7% for the first and second cut respectively; the ratio of green to hay increased 9.5-37.7% and 15.7-33.3% for the first and second cut respectively; the increment of early growth stage heights increased 50.0-163.2% and 22.0-46.5% for the first and second cut respectively; the increment of middle growth stage heights increased 27.2-69.7% and 10.5-44.4% for the first and second cut respectively; the intermodal distance increased 14.9-32.5% and 13.6-39.3% for the first and second cut respectively; the number of internodes increased 15.8-32.2% and 25.0-65.0% for the first and second cut respectively; yield increased 53.5-96.9% and 18.2-46.4% for the first and second cut respectively; dry leaf weights increased 49.8-80.6% and 13.6-39.3% for the first and second cut respectively. S3 promote alfalfa growth at the most extent when compared to S1, S2 and S4, which the research results implied that 105g/m2 was the optimum concentration of silicon fertilization for alfalfa growth.