不同刈割期低纤维苜蓿茎秆生物力学试验研究

Experimental Study on Stems Bio-mechanics of Medicago Sativa Lower Cellulose in Different Harvesting Periods

本文以北方多年生豆科牧草低纤维苜蓿和甘农三号、绿宝石小冠花(对照品种)初花期、结荚期茎秆为研究对象,测试了茎秆的主要力学性能及在不同状态下主要化学成分含量。结果表明:三种牧草刈割处茎秆应力与应变曲线近似呈线性关系;结荚期茎秆抗拉强度大于初花期;初花期刈割处茎秆平均抗拉强度分别是24.62MPa、24.82MPa、15.96MPa;三种牧草茎秆随含水率的降低(或初花期到结荚期的变化),纤维素、木质素、蛋白质含量均增高;低纤维苜蓿平均蛋白质含量介于绿宝石小冠花和甘农3号之间。考虑蛋白质含量、消化率及机械化收获难易,新品系低纤维苜蓿具有更广阔发展前景。此研究为指导牧草优种筛选和选育,设计开发新机具、新工艺提供理论依据。

Three kinds of stems of perennial forage,such as Medicago sativa lower cellulose,Medicago sativa Gannong No.3,Coronilla varial.cv,in different harvesting periods,were chosen to perform the experiments of tensile,the major chemical compositions in different conditions was also determined.The results showed that in the three species,curves of tensile stress-strain of stems were depicted by the straight line relationship.The tensile strength of bottom stems at fruiting stage were greater than at initial bloom stage;the tensile strength of bottom stems at initial bloom stage were 24.62MPa,24.82MPa and 15.96 MPa respectively.The contents of cellulose,lignin and protein of the three kinds of stems were increased with the reduction of moisture content.The contents of protein in Medicago sativa lower cellulose were situated between the Coronilla varial.cv and Medicago sativa Gannong No.3.Considered the contents of protein,the rates of digesting and mechanical harvesting,the new species of Medicago sativa lower cellulose is more popular.The conclusions were the foundation for designing new type of machine,and providing guidance for selecting and breeding the fine varieties.