Effects Of Fertilization On Grassland Vegetation And Soil Physical And Chemical Properties Of Bashang

The grassland in Bashang,Hebei is a green barrier in the Beijing-Tianjin-Hebei region and has rich grassland resources.In recent years,due to the effects of overload and overgrazing,climate warming and other artificial and natural pressures,the grassland on the dam has deteriorated.Grassland degradation is mainly manifested in the decrease of the types of fine pastures,the deterioration of the quality of various pastures,the decline of pasture yields,the fluctuation of the community structure,the deterioration of soil quality,the decline of the grassland ecological function and so on.The quality of grasslands on the dam has deteriorated,leading to the weakening of its main functions such as wind protection and sand fixation,water conservation,soil and water conservation,and greening and beautifying the environment,which will eventually affect the ecological environment in the Beijing-Tianjin-Hebei region.Therefore,the restoration and management of grassland degradation on the dam must be carried out without delay.In view of this,in this experiment,the typical degraded Leymus chinensis grassland in the Zhangbeiba plateau area of Hebei Province was taken as the research object,and the nitrogen,phosphorus and potassium fertilizers were added to the grassland in combination with the enclosure.The experiment investigated the vegetation community composition in August 201 8,and conducted a grassland fertilization experiment in May 2019.Fertilization adopts the "3414" test plan,and sets four-level orthogonal tests of three factors of nitrogen,phosphorus,and potassium,for a total of 14 fertilization treatments.The study analyzed the effects of fertilization measures on grassland pasture yield,quality,nutrient absorption,vegetation community and soil physical and chemical properties in Bashang area.(1)According to the effect of fertilization on grassland forage yield,it can be seen that fertilization can significantly increase grassland forage yield,of which nitrogen,phosphorus,and potassium fertilizers increase the yield in turn by nitrogen fertilizer,phosphate fertilizer,and potassium fertilizer,increasing yields by 58.55%,45.17%,and 42.80%,respectively.Compared with the control,the N2P2K2 forage yield reached the maximum with an increase of 85.70%.Therefore,the optimal amount of N,P,and K fertilizer applied for forage yield was N 60.00 kg·h2-2,P2O5 90.00 kg·hm-2,and K2O 40.00 kg·hm-2.(2)According to the effect of fertilization on the quality of Leymus chinensis,it can be seen that fertilization can significantly improve the quality of Leymus chinensis,and N3P2K2 fertilization treatment has the best effect on the quality of Leymus chinensis,The crude fat content was significantly increased by 30.29%,and the crude fiber content was significantly reduced by-6.69%.Therefore,the optimal amount of N,P,and K fertilizer applied to Leymus chinensis was N 90.00 kg·hm-2,P2O5 90.00 kg·hm-2,and K2O 40.00 kg·hm-2.(3)According to the effect of fertilization on nutrient absorption of grassy Leymus chinensis,it can be seen that fertilization can promote nutrient absorption of Leymus chinensis,and N2P2K2 fertilization treatment has the best effect on nitrogen and phosphorus absorption of Leymus chinensis,of which Leymus chinensis Total nitrogen increased by 28.41%,total phosphorus increased by 37.09%;fertilization treatment N2P2K3 had the best effect on potassium absorption of Leymus chinensis,of which total potassium increased by 14.71%compared with the control,therefore,the most suitable nitrogen and phosphorus absorption by Leymus chinensis nitrogen and phosphorus The combined application amount of potassium fertilizer is N 60.00 kg·hm-2,P2O5 90.00 kg·hm-2,K2O 40.00 kg·hm-2;the optimal combined applicatiol amount of nitrogen,phosphorus and potassium fertilizer for potassium absorption of Leymus chinensis is N 60.00 kg·hm-2,P2O590.00 kg·hm-2,K2O 60.00 kg·hm-2.(4)According to the influence of fertilization on the characteristics of grassland vegetation communities,it can be seen that fertilization can increase the vegetation density and coverage,and reduce the species diversity of the community.Among them,the fertilization treatment N2P2K2 vegetation density reached the highest,an increase of 25.62%compared with the control,while fertilization treatment N3P2K2 The vegetation coverage is the highest,which is 53.85%higher than the control.The Simpson index,Shannon-Wiener index,and Pielou index of grassland vegetation diversity showed a decreasing trend with the increase of fertilizer application,and the richness index did not change significantly.(5)According to the effect of fertilization on the physical and chemical properties of grassland soil,it can be seen that fertilization has no significant effect on grassland soil bulk density,porosity,and water content,but has significant effects on grassland soil pH,organic matter,total nitrogen,available phosphorus,and available potassium,of which the soil effect of 0～10 cm soil layer is more obvious than that of 10～20 cm soil layer.As for the 0～10 cm soil layer,the fertilization treatment N3P2K2 the soil significantly reduced pH by 5.73%,and the soil organic matter significantly increased by 13.86%and the soil total nitrogen significantly increased by 33.83%;the fertilization treatment N2P3K2 soil available phosphorus significantly increased by 54.71%;the fertilization treatment N2P2K3 soil available potassium significantly increased by 21.52%.(6)According to the principal component analysis,the comprehensive score of each fertilization treatment is as follows:N2P2K2、N3P2K2、N2P3K2、N2P2K3、N2P2K1、N2P1K2、N1P2K2、N2P1K1、N1P2K1、N1P1K2、N2P2K0、N2P0K2、NOP2K2、NoP0K0,among them,with fertilization treatment N2P2K2 had the highest score,with a score of 3.49,and without fertilization treatment N0P0K0(CK)had the lowest score,with a score of-5.25.In summary,comprehensive forage yield,quality,nutrients,vegetation community characteristics and grassland soil physical and chemical properties,when fertilizing and improving the typical degraded Leymus chinensis grassland in the Bashang plateau area,the recommended nitrogen,phosphorus and potassium application rate is N 60.00 kg·hm-2,P2O5 90.00 kg·hm-2,and K2O 40.00 kg·hm-2.