Effects Of Gustatory Regulation Of Yak On Grazing Behavior,Vegetation And Soil Trait In Alpine Meadow

The behavior of grazing livestock is affected by taste,and indirectly acts on vegetation and soil.Therefore,the regulation of the taste of grazing livestock is a possible way to manage soil,grass and livestock interaction.Therefore,a three-year warm and cold season experiment was conducted in alpine meadows of the Qinghai-Tibet Plateau to study the effects of bittering agents,sweeteners,and salty agents on the grazing behavior of yaks and their effects on soil physical and chemical properties and soil microbes.The main results are as follows:1.The effect of flavor on grazing behavior.During the three years,bitter tasting agents reduced the feed intake of grazing calves in the summer,and salty agents increased the feed intake of calves.In winter,sweeteners increased feed intake in 2015 and bitterers reduced calf intake in 2016.In 2017,sweeteners and bitterants inhibit calf intake and sweeteners promote calf intake.The effect of the taste agent on the calf's feeding rate was as follows: the taste of sweet and sour taste of salty taste,bitterness,and taste;the effect on the calf's foraging speed was opposite.2.Salty agents,bitters,and sweeteners have different effects on different pastures.Salty agents can significantly improve the palatability of pastures and promote the feeding of grazing livestock;the effect of sweeteners is not obvious;the bittering agents are different.Pastures all play a broad inhibitory role.3.Effect of yak taste regulation on alpine meadow vegetation.The existing amount of alpine meadow land under the treatment of various flavors is: bitter miso control,sweet taste,salty taste.From June to August,under the treatment of the same flavor,there was no significant change in the existing amount of grassland above-ground,but it was significantly lower in the warmer season of December.The existing quantity of dominant species or functional groups.The index of community diversity was: bitter taste,control,sweet taste,salty taste.Taste regulation had no significant effect on the contents of ADF,NDF and CP in dominant plants of alpine meadow.4.The effect of yak taste regulation on alpine meadow soil.The soil pH value graduallyincreased from 0-10 cm to 30-40 cm in the soil layer;in 2016,the pH of the deep soil in the plots treated with sweeteners and bitterants decreased in the warm season and the cold season respectively;in the summer of 2017,the salty agent Significantly reduce surface soil pH.The bittering agent significantly improved the soil moisture content of 10-20 cm in summer 2016,and the salty agent reduced the 0-10 cm soil moisture in winter 2017.The salty agent reduces organic carbon in the topsoil of the 2016 and 2017 summers and winter 2017.The regulation of salty seasoning caused the content of total nitrogen,ammonium nitrogen and nitrate in the surface soil in summer and the nitrate content in surface soil in winter 2017 decreased.5.Effect of yak taste regulation on soil microorganisms in alpine meadow.Soil microbial carbon in 0-10 cm soil was significantly reduced in the bitter agent-treated plots,and the salty agent plots were significantly increased;microbial nitrogen was significantly increased in the salty,bitter and sweetener treatment plots.In 2016,there was no significant change in the microbial diversity index of the flavor treatment plots;in 2017,salty additives significantly reduced the soil microbial diversity index.Salty agents reduce the abundance of Actinomycetes,bitter agents decrease the abundance of Chloroflexi and Bacteroidetes,sweeteners reduce the abundance of Actinomycetes,and three types of taste improve Gemmatimonadetes and Nitrospirael richness;Proteobacterial door richness did not change significantly.