Study On Evaluation Of Nutrient Quality And Anti-nutritional Factors Of Alfalfa In Saline-alkali Soil

In this thesis,under the background of shortage of cultivated land resources and high-quality forage in China,the development of alfalfa industry in saline alkali land is not only in line with the national development strategy of grassland and animal husbandry,but also can change the situation of lack of high-quality forage.The experimental site is located in Jiuyuan District,Baotou City,Hetao area,Inner Mongolia,taking"Zhongmu No.3"as the research object.In order to provide theoretical basis and technical support for high-quality alfalfa production in saline alkali land,the dynamic law and correlation of the degree of salinization on alfalfa agronomic traits,nutritional quality,anti nutritional factors and other indicators were studied by comprehensively,taking the degree of salinization and stubble times as the breakthrough point.The results are as follows:(1)The degree of salinization had a significant effect on the agronomic traits of alfalfa.The fresh grass yield and plant height of alfalfa in each stubble of mild saline alkali soil were the highest,which were 2567.95kg/hm~2 and 79.50cm,respectively,which were significantly higher than those of other treatment groups(P<0.05);The yield and plant height of the first stubble were significantly higher than the second and third stubble,but there was no significant difference in leaf number,leaf length and leaf width among the three stubble.(2)The degree of salinization and stubble times had an effect on the accumulation of nutrients;The content of crude protein and non structural carbohydrate had a positive relationship with the degree of salinization,and the degree of severe salinization increased by 9.60%and 42.31%on average compared with the control group;The content of neutral detergent fiber and acid detergent fiber decreased by 10.90%and 15.34%respectively.(3)With the increase of salinization degree,the content of Na~+and K~+of alfalfa increased gradually.The contents of Na~+and K~+of alfalfa in severe saline alkali soil were significantly higher than those in other groups,and compared with the control group,it increased by 87.50%and 30.83%respectively.(4)The salinization degree and stubble times had an effect on the accumulation of anti nutrition factors of alfalfa;The contents of phytic acid and total polyphenols in severe saline alkali soil were significantly lower than those in control group(P<0.05),decreased by 13.4%and 30.3%respectively;The content of saponin was significantly higher than that of the control group,increased by 30.36%The content of oxalic acid was the highest in each stubble of Alfalfa in mild saline alkali soil;There was no significant difference in tannin among treatments(P>0.05).