| The Qinghai-Tibet Plateau is the most widely distributed traditional pastoral area in China.At present,the gramineous grass with strong cold resistance is the most important forage in the region,and the protein content is low,which can not satisfy the nutritional requirements of grazing livestocks.It is necessary to introduce high quality leguminous forage with high crude protein content.However,planting alfalfa has the problem of slow growth and wintering in the same year in the alpine region.Studying the mechanism of furrow and mulch film planting method in promoting growth and increasing the wintering rate of alfalfa under dry farming conditions in the alpine region,it can provide a basis for alfalfa planting in alpine regions or similar areas.The experiment was set up with film mulching on ridge and furrow(FMRF),film mulching parallel to the ground(MPG),ridge and furrow treatment(RF)in the northeastern margin of the Qinghai-Tibet Plateau,the Tianzhu alpine region of Wuwei City,Gansu Province.The temperature and moisture,nitrogen characteristics,organic matter content,enzyme activity,morphological indicators,photosynthetic indexes and underground physiological indicators of alfalfa were studied.The research results are as follows:1.The FMRF treatment and MPG treatment increased the germination rate of alfalfa on the northeastern edge of the Tibetan Plateau.Compared with the RF treatment,the emergence rate and emergence days under the FMRF and MPG treatment were increased by 67.84%,41.06%and 10 d and 8 d;the number of alfalfa branches and stem base under the FMRF and MPG treatment increased by 100.00%,53.2%,55.74%and 35.25%;FMRF and MPG treatment significantly increased plant height,aboveground biomass,underground biomass,root bud number,main root diameter,main root length,root neck diameter and number of lateral root;the overwintering rate of alfalfa under the FMRF and MPG treatment was increased by 25.76%and 23.79%.Compared with the RF treatment,the FMRF and MPG treatment significantly increased the leaf area and SPAD content of alfalfa,which increased the P_n,G_s,T_r,WUE and L_s value,and decreased the C_i concentration.2.Film mulching increases soil temperature and moisture content.The descending order of the contents of nitrate nitrogen,ammonium nitrogen,total nitrogen,alkali nitrogen,organic,invertase,urease and catalase active under the soil layers of 0-10 cm,10-20 cm and 20-30 cm is MRF-R>FMRF-F>MPG>RF-R>RF-F.3.The ascending order of the contents of reducing sugar,starch,soluble sugar,soluble protein and PRO is FMRF<MPG<RF,and the FMRF treatment was significantly lower than that RF treatment(P<0.05).The descending order of the content of MDA is FMRF>MPG>RF,while root SOD,CAT and AsA-POD content under the FMRF treatment were lower than that of MPG and RF treatment.The FMRF treatment significantly increased the content of hemicellulose in the cell wall of the roots(P<0.05),increased the cellulose content in the cell wall of the plant roots,while significantly reduced the content of ADL in the plant cell wall(P<0.05).4.Film mulching increases soil temperature and moisture content.The overwintering rate of alfalfa was extremely significantly positively correlated with plant height,main root diameter,main root length,root neck diameter,root bud number,underground biomass,aboveground biomass,branch number,stem base,lateral root number and leaf area(P<0.01),and it was correlated with alfalfa root SOD,CAT,MDA,hemicellulose and cellulose were significantly positively correlated(P<0.05);While negatively correlated with root starch,reducing sugar,soluble protein,soluble sugar,AsA-POD,PRO,and ADL(P<0.01). |
PDF Full Text Request