Tan Sheep Grazing Effects On Growth And Propagation Of Herbage In Typical Steppe

Rotational grazing system is the basis of the sustainable development of modern grassland animal husbandry.To study,with 15 years rotation grazing system of Tan sheep-typical grassland as the research object,analyzes the effects of foraging,excrement and trampling on the growth and reproduction of three dominant species,respectively.And further,we analyze effects of stocking rate and grazing season on soil seed bank and the role of livestock manure in seed germination.The main results are as follows:1.Effects of Tan sheep excreta on growth and reproduction of dominant speciesAfter 1 month of urinary addition,the growth and flowering branch rate of Artemisia capillaries reached the smallest at 1.5 L/m2 and significantly lower than that of the untreated group(P <0.05).The growth rate of L.davurica and S.bungeana were not significantly affected in 2015(P <0.05).But the growth rate of the two forages was higher than the blank control group in the urine after 2 months in 2016.It can be seen that the urine has a short-term inhibiting growth effect on plants,but this effect can transform into a promoting effect over time.This effect is primarily determined by plant species and environmental conditions.In the short term,the growth and reproduction of the three forages were not significant,but with the decomposition of manure,there is a trend to promote the growth of three forages.2.Effects of trampling on forage growth and reproductionThe trampling promoted the lateral growth of Lespedeza davurica and Stipa bungeana,and trampling on a month was significantly higher than that in the untreated group(P <0.05).In the short term on the grass trampling on the role of sexual reproduction varies from species to species,the same trampling intensity,Artemisia promoted by sexual reproduction(P<0.05)and Lespedeza was inhibited(P<0.05)3.Effects of ingestion on forage reproductionThe livestock grazing shows that increases first and then decreases trend with grazing time.With the increase in grazing rate,feed intake has a downward trend.The grazing can increase the ratio of reproductive branches of Artemisia capillaries and Lespedeza daurica,but did not produce significant effects(P> 0.05).4.Effect of grazing on soil seed bankThe soil seed bank of the warm and cold season grazing land was the lowest at 8.7 sheep / ha grazing rate and significantly lower than that of 0 sheep / ha grazing rate(P <0.05).The seed bank density of 5-10 cm soil layer in grazing land was increased with the increase of stocking rate.It indicated that grazing can significantly reduce the total density of soil seed bank and affect the vertical distribution of seed bank.The soil seed bank species diversity increased with the increase of stocking rate(P<0.05).This shows that grazing can change the species diversity of the soil seed bank,but there are differences because of the different grazing season.The grass fecal spots covered area reached a maximum of 8.7 sheep/ha warm season grazing land,and there was a significant difference between the years(P<0.05).This suggests that fecal patch distribution is affected by forage resources and grazing time.In the warm season,the number of seeds in the dry feces was significantly higher than that of the fresh feces(P<0.05).There was no significant difference between the dry and fresh feces in cold season grazing(P<0.05).The seeds of germination were mainly with Artemisia capillaries and Potentilla bifurca Linn,it can be seen that the seed dispersal of livestock through the feces was affected by grazing time,feces shape and seed morphology.The results showed that grazing could reduce the density of soil seed bank and improve the diversity of species.Excreta,food intake and trampling have positive effects on the growth and reproduction of the typical grassland dominant forage under certain conditions.Therefore,this study shows that appropriate grazing will help the sustainable management of grassland farming in the typical grassland.The germination rate of the seedlings was decreased by 14.5%(P <0.05),30%(P <0.05)and 32%(P <0.05)under 0.05,0.1 and 0.15 L urine.Lespedeza in 0.1L urine output,the germination rate dropped to 0%(P <0.05).This shows that urine can inhibit the flow of Lespedeza,longan grass seeds,and Lespedeza tolerance threshold lower.