甘肃省不同草原类牧草生长中后期养分含量及动态研究

Study on Nutrient Content and Dynamics of Different Grassland Types for Middle-Late Growth Stage in Gansu Province

为评价甘肃省不同草原类草地可食牧草生长后期养分含量及动态变化,分别于2020年7月上旬、8月中旬和9月下旬选择代表性样地布设样方进行地面调查并采集可食牧草样品进行常规营养成分检测。结果表明,7—9月各草原类可食牧草CP含量随牧草生长期延续降低,而NDF和ADF含量则增加,平均CP含量从7月的11.54%,分别下降至8月和9月的10.87%和8.43%,位于南部高寒和高山区的山地草甸、高寒草甸和高寒草原牧草CP含量较高,而中部干旱区的温性草原较低。各草原类的EE含量介于3.47%~3.85%之间,以温性草原较高。各草原类Ca含量呈先下降后上升而P含量呈逐渐增加的趋势,分别介于0.57%~1.00%和0.10%~0.23%之间。各草原类营养类型由NC型逐渐向CN型转变,其中山地草甸、高寒草甸、低地草甸和高寒草原9月转为CN型,暖性灌草丛8月转为CN型,温性草原7月即为CN型,而温性荒漠全期均为A-NC型。

In order to evaluate the nutrient content and dynamic changes of edible forages in different grassland types of Gansu province,selected representative sample plots,laid quadrats for ground investigation,and collected edible forage samples for routine nutrient detection in early July,mid August and late September in 2020 respectively.The results showed that the CP content of edible forage in different grasslands decreased with the continuation of forage growth period from July to September,while NDF and ADF were opposite.The average CP content decreased from 11.54%in July to 10.87%in August and 8.43%in September,respectively.In the southern alpine region,the content of CP in mountain meadow,alpine meadow and alpine grassland was higher,in warm steppe was lower.The EE content in each grassland was between 3.47%-3.85%,and all of them were higher in warm steppe.The Ca content decreased first and then increased which between 0.57%-1.00%,the P content increased gradually which between 0.10%-0.23%.The nutrient types of grassland gradually changed from NC to CN type.Among them,mountain meadow,alpine meadow,lowland meadow and alpine grassland changed to CN type in September,warm shrub tussock changed to CN type in August,the warm steppe was CN type in July,the temperate desert was A-NC type in the whole period.