Adaptability Evaluation Of Inductive Perennial Grasses In Saline-alkali Grassland In Songnen Plain

Screening excellent forage varieties adapted to saline-alkali environment grassl in Songnen Plain isvery important for providing forage resources for the vegetation recovery of saline-alkali grassland andalso has great reality significance on the ecological function recovery of grassland ecosystem andsustainable development of animal husbandry. The growth characteristic and nutritional quality offorage varieties and the effect of20forage varieties introduced and gathered on soil properties wereevaluated in the typical saline-alkali grassland in Songnen Plain. At the same time, the ecologicaladaption of20forage varieties was synthetically estimated by method of Analytic Hierarchy Process(AHP). The results indicated:Survival rate of less than30percent after winter of P. pratensis L, P. pratensis L. var. anceps, P.pratensis L. Qinghai,Festuca sinensis Keng and E. nutans Griseb indicated that5forages has lowerability of over winter. These5forages died three years later. Overwintering rate of other15foragerswere beyond80percent, this means these forage varieties can adapt to the climate and soil condition insaline-alkali grassland in Songnen Plain.Some characteristics of15forage varieties (such as plant height, growth rate, plant density, yield andbelowground biomass) and their dynamics were different. The plant height and growth speed ofRoegneria nutans (Keng) Keng were highest compared with other14forage varieties, and the averageof plant height and growth of4years were107.2cm and1.84cm/d respectively. The plant height andgrowth speed of Agropyron cristatum var. Pectiniforme were lowest and they were63.80cm and0.75cm/d that showed significant differences among15forage varieties(p<0.01). The average of plantdensity of4years were between643.6～2020.2plant/m2, and the plant density of Hordeum bogdaniiWilensky was significant higher than other14forage varieties (p<0.05). The fresh grass yield and hayyield (fresh grass yield was13989.0kg/ha and hay yield was6599.3kg/ha) of Hordeum bogdaniiWilensky were highest among15forage varieties. The grass yield of Agropyron cristatum var.Pectiniforme was lower than other14forage varieties and fresh grass weight and hay weight only33.90%and36.18%of Hordeum bogdanii Wilensky. The belowground biomass of Elymus dahuricuswas highest and it was466.72g/m2and the lowest belowground biomass was Agropyron cristatum var.Pectiniforme.The crude protein content of Elymus dahuricus Turcz. was15.22%and it was significant higher thanother forage varieties. The crude fat content and its seasonal dynamics of every forage varieties weredifferent and the results of analysis of variance showed significant differences between any foragevariety(p＜0.05). The crude fiber content showed significant differences between every forage variety(p＜0.01), but no significant differences was found between every month(p>0.05).Soil physical and chemical conditions and nutrients were significant ameliorated than before. The soilmoisture content, pH, bulk density and soil salt content of forage field planting were significant lowerthan control pilot. The soil moisture of plant field was20.55%to22.35%and lower3.99%to5.79% than control pilot (control pilot soil moisture content was26.34%). Soil pH was8.49to8.74and lower0.49to0.74than control pilot (control pilot soil pH was9.23). The soil bulk density was1.49to1.66and less0.19to0.36than control pilot (control pilot soil bulk density was1.85). The total salt content ofsoil was0.4478%to0.5192%and less0.1058%to0.1772%than control pilot (control pilot soil totalsalt content was0.6250%). The nutrient content of soil planting forage of significant higher than controlpilot. The organic matter content of soil planting forage which had plant four years was twice2.86timesthan saline-alkali grassland, and available nitrogen increased by130.5%and available phosphorusincreased by159.1%.The order from high to low for forage evaluated by Analytic hierarchy process (AHP) was: Leymuschinensis（Trin.）Tzvel. Nongjing No.4, Hordeum bogdanii Wilensky, Elymus dahuricus Turcz., Elymus dahuricus, Leymuschinensis（Trin.）Tzvel., Bromus inermis fleet, Bromus inermis Leyss., Elymus trachycaulum, Roegneria nutans (Keng)Keng, Agropyron cristatum L, Agropyron desertorum Schult., Roeneria japonensis, Agropyron cristatum var.Pectiniforme, Agropyron mongolicum, Festuca sinensis Keng, Agropyron cristatum (Linn.) Gaertn, P. pratensisL.Qinghai, E. nutans Griseb, P. pratensisL. var. anceps and P. pratensisL.. Some forage was not suitable for plant in thisregion, such as, Festuca sinensis Keng, P. pratensisL. Qinghai, E. nutans Griseb, P. pratensisL. var. anceps and P.pratensisL.