Relationship Between Planting Density And Seed Yield, And Turf-used Properties Of Cleistogenes Songorica

The native grasses play an important role in development of grassland animal husbandry, ecological protection and lawn industry. Present study were conducted with Cleistogenes songorica in the third year and the fourth year after sowed to explore the relationship between planting density and seed yield, and in the first year and the seconed year to study turf-used properties of C. songorica in the northwest of China (Gansu province) during two continual growing seasons from 2008 to 2009. The results showed that:1.Planting density significantly affected the seed yield, harvest index and aboveground biomass of C. songorica (P<0.05), and as plant density increased from 5 plants/m2 to 50 plants/m2, they are increased first and then declined during two continual growing seasons. In 2008 and 2009, the highest seed yield(636.2 kg/hm2 and 387.6 kg/hm2, respectively) and harvest index(21.3% and 15.9%, respectively) were obtained in two growing seasons under 30 plants/m2 treatment. Aboveground biomass (3127 kg/hm2 and 2860 kg/hm2, respectively) under 50 plants/m2 treatment performed great significantly than the other treatments, except for 30 plants/m2.2. Seed yield in 2008 was significantly higher than in 2009 under all treatments. Ratio of actual seed yield and potential seed yield under 5 plants/m2 (52.5%, 47.3%) and 10 plants/m2(42.8%, 35.3%) were significantly greater than other treatments in two years.3. In two years, plant height increased when the plant density increased from 5 plants/m2 to 50 plants/m2, but the canopy width declined. The highest plant height were 70.1 cm and 71.6 cm under 50 plants/m2 treatment, and the canopy width (89.3cm and 89.7cm, respectively) reached the maximum value when the plant density at 5 plants/m2.4. Plant density significantly affected the seed yield components, such as fertile shoots number/m2, spicas/shoot, seeds/spica and 1000-seed weight. The seed yield most closely correlated with fertile shoots number/m2, the former were significantly positive correlated with the latter for each treatment in two growing seasons, the simple correlation coefficients were 0.741 in 2008 and 0.780 in 2009, and the direct path coefficients were 0.362 in 2008 and 0.788 in 2009, respectively, which implied fertile shoots number/m2 was the most important key botany component in determining seed yield, we should improving the fertile shoots number per unit area when constructed seed production field of C. Songorica.5. The field experiment was conducted to comprehensively evaluate and compare turf-used properties between C. songorica and two varities of tall fescue in this study. Under the ralative drought condition(irrigated every 10 days), compared with two varities of tall fescue(Houndog 5 and water saver), C. songorica have the good turf-used properties, such as turf texture, coverage, density etc. Performance of C. songorica in different types of turf were different, and the results of assessment score were order from highest to lowest: ecological turf> ornamental turf> recreation turf> athletic fields turf, and the comprehensive assessment score was 9.81, and Houndog 5 and water saver were 8.08 and 8.54 respectively. C. songorica can be used as a key native grass varities for establishing ecological turf and ornamental turf in arid area.