The Integrated Technology Research On Bermudagrass Sod Production Using Sludge From Municipal Wastewater Treatment Plant

The problems of the traditional sod production and the drawbacks of solid waste disposal prompt a new mode of sod production-waste soilless sod. However, many factors including excessive heavy metal, heavy sod roll and long sod-forming days limit the soilless sod production and promotion. This paper focuses on the research that using waste to produce the bermudagrass sod, using randomized block design to explore the optimal choice of a single waste, using single lattice design to explore ways to choose the best substrate composition, using regressive and rotation design exploration to select the best substrate thickness and sowing quantity and fertilizer ratio combinations, using principal component analysis and correlation analysis to explore the relation of independent and dependent variables and dependent variables themselves. The main results are as follows:1、The sod quality character, operating costs and environment benefit of the five soilless medium (coal cinder, sawdust, municipal sludge, waste compost and mushroom) were analyzed. The result indicated that the content of heavy metal was obviously reduced. The sod colour, coverage and overground biomass of municipal sludge were good, and the difference with other treatments was significant(P< 0.05). The total biomass and underground biomass of municipal sludge were good, and the difference with other treatments was significant(P< 0.05) except coal cinder. The difference of sod freshness was not significant(P>0.05).All index were considered, the order from good to bad was municipal sludge (δmunicipal sludge=0.885)>mushroom(δmushroom =0.674)>sawdust(δsawdus=0.598)>waste compost(δwaste compost=0.550)>coal cinder(δcoal cinder=0.543). That was to say, municipal sludge was the best soilless medium of the bermudagrass sod.2、Through making use of municipal sludge as the major medium and choosing coal cinder, mushroom, and sand as compound materials to produce bermudagrass soilless sod, the medium selection and compounding were carried out. The result indicated that, the content of the municipal sludge, coal cinder, mushroom and sand were 51.41% to 1.83%, 18.32% to 18.86%,18.19% to 18.81% and 10.87% to 11.72% respectively.3、The correlation between thickness and turf-establishment was positive. The correlation was negative between thickness and root system activity. The relation trendline was sunken parabola including thickness with sod weight, biomass and density and sowing quantity with turf-establishment days and sod-forming days. The relation trendline was raised parabola including thickness with sod-forming days and sowing quantity with underground biomass and density. Besides, other relations were all unconspicuous. The comprehensive of quality evaluation of correlation analysis with the grey systematic theory were used for searching for the optimize section. Then the optimize section range of thickness and sowing quantity were respectively 0.677cm to 0.726cm and 152.697g/m2 to 162.885 g/m2.4, The correlation of N with chlorophyll was positive. The relation trendline was raised parabola including N with biomass, density, root system activity and relevancy value. The relation trendline was sunken parabola including N with sod-forming days and turf-establishment days. The relation trendline was raised parabola including P with biomass, density and root system activity. The relation trendline was sunken parabola including P with sod-forming days. The correlation between P and turf-establishment days was negative. The relation trendline was sunken parabola including K with sod-forming days, he relation trendline was raised parabola including K with density and overground biomass. Besides, other relations were all unconspicuous. Then the optimize section range of N and P were respectively 13.313 to 14.541 g/m2 and 5.827 to 6.549 g/m2.5、The correlation analysis of the experiment of thickness and sowing quantity results showed that:Biomass was removed after principal component analysis. The correlation between thickness and all sod quality character was significant except density. The correlation between thickness and root system activity was significantly negative. The correlation between sowing quantity and density was significantly negative. The correlation between sowing quantity and turf-establishment days was significantly positive. The correlation analysis of the experiment of fertilizers test results showed that: Overground biomass was removed after principal component analysis. The correlation between N and underground biomass, density and chlorophyll was significantly positive. And the correlation between N and P and sod days was all significantly negative. The correlation between P and underground biomass and root system activity was significantly positive. Relative to other indicators, the density was greater influenced by K content.